2017 hottest summer in California history; Cut-off low may bring widespread thunderstorms

Filed in Uncategorized by on September 9, 2017 4,167 Comments

Overview of recent all-time record California heat

2017 was the warmest (or near-warmest) summer on record over most of the Western U.S. (NOAA/NCDC)

2017 brought extraordinary summer heat to California. While record-breaking early-season heatwaves largely spared the immediate coastal areas (but brought endless weeks of searing triple-digit heat to interior areas), extreme temperatures extended all the way to the beaches over the past couple of weeks.

The late summer and early autumn months are traditionally warmest of the year in coastal California, as the marine layer tends to become suppressed and offshore winds occasionally allow hotter air to encroach from the east. But the late August and early September heatwave that California just endured was on an entirely different level than those historically experienced–breaking (and, in many cases, shattering) temperature records of all kinds. Countless daily (and monthly) temperature records were set statewide, and this heatwave continued the already record-breaking streak of 100+ degree days across much of the Central Valley. Overnight temperatures stayed well above average daytime highs in many places, and new all-time “warmest minimum” records were set. Quite a few coastal or near-coastal California cities matched or exceeded their all-time temperature records for any month–an impressive list that spans from the North Coast (Eureka) to the central coast (San Luis Obispo) and apparently even includes (amazingly) the Farallon Islands in the midst of California’s cold oceanic upwelling zone. Easily the most amazing statistic during this extraordinary event was the fall of downtown San Francisco’s all-time temperature record, where the observed 106 degrees surged past the previous hottest temperature (103) in 147 years of record keeping.

It might not be a surprise, therefore, that summer 2017 was officially California’s hottest on record (and much of the Labor Day heatwave actually fell out outside of the formal June-August definition of “summer”). In fact, 2017 broke (by a considerable margin) the previous record set…just last year, in 2016. Indeed, this year once again puts an exclamation point on a sustained, long-term warming trend over the past century in California. Increasing frequency and intensity of extreme heatwaves is one of the clearest hallmarks of our warming climate, and it’s likely that “extreme” temperatures like those experienced this summer will become fairly routine in just a few decades.

California has experienced a sustained long-term warming trend in summer, and 2017 was the warmest season on record. (NOAA/NCDC)

 

Unusually widespread thunderstorm outbreak possible across California

An offshore cut-off low will be in a favorable position to produce relatively widespread thunderstorm activity. (NCEP via tropicaltidbits.com)

A slow-moving cut-off low pressure system is currently setting up shop off the Southern California coast, and has the potential to bring some very active weather to certain parts of the state over the next 5 days. Mountain and desert thunderstorms have already been quite active over the past few days, but beginning on Sunday convective development is likely much closer to (and perhaps including) the coast. In fact, convective parameters for late tomorrow afternoon for much of Southern California and the Central Coast are quite impressive, with able mid-level instability, sufficient column water vapor, and even some large-scale ascent forced by diffluent flow east of the offshore low.

With all of these ingredients in place, numerous thunderstorms will likely develop over the mountains of Southern California tomorrow afternoon, at least a handful of which will sustain themselves as they move east to west over the coastal plain and even offshore. At least a few of these storms may be quite strong (or even severe), bringing intense downpours along with possible hail and gusty winds. This, tomorrow could be a pretty active weather day even in places that rarely see this kind of vigorous thunderstorm activity.

An offshore jet streak will provide dynamical support for thunderstorms over the SoCal Bight on Sunday. (NCEP via tropicaltidbits.com)

There is at least a modest risk of flash flooding in interior areas hit by strong storms, and some localized issues could even occur outside of the mountains. It’s actually possible that thunderstorms may be more widespread tomorrow across portions of SoCal (including Los Angeles County) than they were during the recent “Lidia” tropical remnant event. (On a related note, if you haven’t checked out this video showing extraordinary webcam footage of the highly localized but quite damaging Santa Barbara microburst last week, you really should. Also, this one.).

On Monday and Tuesday, the thunderstorm threat will shift northward to encompass most of the rest of California–even including the Bay Area and Central Valley.

The GFS is showing fairly widespread precipitation accumulations over most of California over the next 5 days. (NCEP via tropicaltidbits.com)

Scattered thunderstorms may ultimately occur uniformly over much of NorCal as moisture and instability will be present virtually everywhere. This sort of synoptic set-up–with a fairly deep offshore cut-off low and modest amounts of late monsoonal moisture–is reminiscent of the sort of pattern that has historically caused spectacular early autumn lightning displays over parts of California. Hopefully, this event will be associated with enough wetting rainfall to avoid numerous wildfire strikes, but given the time of year and the antecedent heat/dryness, this event will probably pose a significant fire weather threat.

Later next week, the cut-off low will finally move inland and perhaps bring a final round of isolated showers and thunderstorms to a fairly broad area (perhaps even the coast), though coverage and intensity should be less than earlier in the week. After that, quieter weather conditions will likely return.

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  • Taz & Storm Master

    am in joying the snow fall on this cam tonight

    • Taz & Storm Master

      I want that please

      • GR

        Jimmy Stewart going to come running into the frame shouting ‘Merry Christmas’?

  • Great Winter of 2017 (SMC)

    My thinking, storm door opens in late October and several significant storms occur through early December and then gets much colder with more moderate storms to end December!

    • Hollow Scene (Riverside)

      About time for a December 2008 repeat storm down here

  • Fairweathercactus

    Gather around it is time for an old cactus story.

    When I was a younger much more optimistic cacti I remember one of the fastest moving storms that I recall. It was February of 1998.. The rain was expected to move in early in the morning. I woke up and it was 100% clear. No clouds at all where found. I remember my dad as he was dropping me off to school said that it looked like the storm was a bust. Then I remember the kids at school saying the same thing. I was telling everyone the storm was still going to take place.

    We had a field trip down the block to the local library that day. We walked over and it was still nearly clear and I was starting to lose hope. We where in there for only an hour. Time we got out the street was flooded on the way back. Huge convective drops and even a bit of hail. It dried up quickly before the end of the day. Over 2 inches of rain fell in a short amount of time.

    • weathergeek100

      Nothing like the storms of Feb 1998. Nothing. I was in 6th grade that year and I got distracted by the pouring rain outside the classroom as the teacher was trying to teach math/science/english/history. Weather channel was my source. I recall wording like “heavy rain” and “rain/wind” forecasted for the next 3 days in the local forecast and I would get beyond excited.

      Besides the weather channel, local news was my source. John Coleman and Loren Nancarrow were my favorite celebrities on TV (the latter recently passed away from cancer unfortunately). This was in San Diego.

  • Cap’n

    2016-2017 water year is now wrapped up. Looking at my highly scientific jottings in the $1.00 notepad purchased from CVS and measured with an $8.00 glass rain gauge and yard stick; I’m relatively confident in my recordings, especially comparing them to some of the great graphs I’ve seen posted here regarding the measurements throughout the stations in the Sierra. Having said that, it appears that the elephant in the room of my recordings are the huge rain totals for both January and February. There was so much precipitation falling as both snow and rain back and forth that it was tough to be accurate. I’d say the rain totals for those months are too high. I got a tremendous amount of precipitation as I sit directly below the crest in what I’ve scientifically named “The Toilet Bowl,” but I find it difficult to believe that we received more than Blue Canyon. If I used snow ratios of 8:1 or even 10:1, that would put me over 100″ which again sounds high. 12:1 ratios would bring that down a bit, but the average snow ratios of our storms was Not that high. So these are the numbers I have logged but I’d feel confident in calling the margin for error 15-20″ for the rain column and maybe 3-6 feet for the snow. What a crazy January that was…

    Apparently I was in a blackout for the months of May, July, and August.

    Attached two pictures from March 5th of my back porch and the snack shack down the street. Maybe I’ll be showing these to my grandkids in 50 years.

    https://uploads.disquscdn.com/images/47bc88d11f97ccd9240a775a69e5611fc1a1f3874fe16045dfaf5aee1d76ec21.jpg https://uploads.disquscdn.com/images/a56fcb1dbcadc0b3adab3fe5adf0da8d98a7c1ea67d5860dcbf7e5ca4f8b22b1.jpg https://uploads.disquscdn.com/images/651aba458c4271c8925eea0ceb3c97f1032096dde2d57c13fa8ad2a6d862850f.jpg

    • Jason Jackson Willamette

      Wow! 18.4″ of rain in Feb. Hoping for a repeat.

    • I’d say your numbers are probably pretty accurate. The storms you had last water year were favorable for your location with so many of the AR’s directed your way. I remember you being so excited about moving there because it was an area that was known for a lot of precipitation.

    • Great Winter of 2017 (SMC)

      I remember you being tired of the storms in January, how do you feel now?

  • Fairweathercactus

    Here are some Octobers where Downtown got shut out for rain in October.

    1997
    1998
    1999
    1991
    1992
    1990
    1980
    1977

  • Jason Jackson Willamette
  • Jason Jackson Willamette

    Anyone know if it’s going to rain this winter in California?

  • Great Winter of 2017 (SMC)

    Thanks WY 2016-2017
    Oct: 4.11 inches| 11 days of rain
    Nov: 1.72 inches| 10 days of rain
    Dec: 4.49 inches| 9 days of rain
    Jan: 13.58 inches| 18 days of rain
    Feb: 10.27 inches| 19 days of rain
    Mar: 3.55 inches| 6 days of rain
    Apr: 3.22 inches| 9 days of rain
    May: .10 inches| 2 days of rain
    June: .10 inches| 1 day of rain
    Aug: 0 inches | 0 days of rain
    Sep: .25 inches| 1 day of rain

    WY totals: 40.81 inches of rain ( 199% of average) 86 days of rainfall ( 143% of average)

    • BRP (Ventura)

      Great data from San Carlos! Thanks for sharing with us. 86 days of rain falling from the skies, incredible. Just 300 miles south of you, I had 37 days. Damn Pt. Conception!

  • Darin

    It’s article in The Guardian about LA, the death of palm trees, and how heat may change the LA visage. ( https://www.theguardian.com/us-news/2017/sep/29/los-angeles-palm-trees-dying?mc_cid=682ab2f687&mc_eid=9f33451ef2 )

    • To add I’ve never seen so many redwood trees scorched by the Labor Day heat wave. It was 108 and 114.

  • Daniel quoted in the NYTimes today:
    https://goo.gl/KhtePX

    • Excellent points brought up especially Daniel’s.
      Correct me if I’m wrong but when the author says “other soothsayers” and only has one (Farmers Almanac) doesn’t that imply the others mentioned are also? They are not of course.
      Also: Weather Scientists in the beginning of the article and later in the article there is a transformation to Climate Professionals.
      I’m nitpicking the writer not the subjects information.

    • Chris

      Great article.
      I just wish The Farmers Almanac….. as well as other fake news…. would just go out of business.

  • Thunder98 (Santa Maria Valley)

    45F and patchy fog. Cooler than the forecasted low.

  • Taz & Storm Master

    we could see a major pattern shift come around mid OCT right now thats still a little low but models do seem to be hitting at may be some rain around mid oct too the 3rd week of oct

  • weathergeek100

    Very ‘Santa Ana’ like morning here in the bay area. As of 8:05 AM, dewpoint is 34 with a temp of 63 at Oakland Int’l. Humidity is 34%.

    I know it’s still a bit early in the season, but I’m ready for some rain. A few more weeks of the dry season left and by then hopefully we’ll have some sort of pattern change.

  • DayHoe Herald

    Sustained wind event in Yolo that’s rearranging the dust — looking forward to first rains to cleanse things a bit

    • Pfirman

      Chico and north to CHeden gets the same as we do. You might have some dust from Cottonwood on your windowsills and in your lungs today.

      • It was cranking across the valley along 152. A real mess blowing dirt/dust everywhere

  • CHeden

    GFS still flirting with something moving up from the tropics….but still can’t get more than a toe in the water. After the 00Z run spit out another promising solution, as usual, the very next run (06Z) shows bupkis.
    Wonder what the 12Z will show?
    Methinks until a tropical system actually does/if comes together off Cent. America, these kind of tease and hide runs from the GFS are going to continue.
    But, it’s sure been fun to watch from the sidelines….even if there is no credible reason to believe any of the forecasts (ATTM).
    https://uploads.disquscdn.com/images/666972fd1bf1c15386d90eec9a068d8923e67e17bc0aba3cb3f148ac9176ff1f.gif https://uploads.disquscdn.com/images/17f52229f3a9ef4443a08d44a6fc342554b56f99b3b4f6eb9d4936d36f90d447.gif

    • Tyler Price (Carmel Valley)

      00z had a bullseye on my house! 🙂 and the Monterey Bay peninsula! Haha I got a feeling something is brewing around the 10-15th

      • Pfirman

        “But, it’s sure been fun to watch from the sidelines….even if there is
        no credible reason to believe any of the forecasts (ATTM).” CHeden.
        Not everyone needs credible reasons, eh?

    • Great Winter of 2017 (SMC)

      90E, As of 5:00 am PDT Mon Oct 2 2017 …
      A small low pressure system located a couple of hundred miles south
      of southeastern Mexico is accompanied by disorganized showers and
      thunderstorms. Environmental conditions are expected to gradually
      become more conducive for development over the next few days while
      the system moves slowly west-northwestward or westward.
      * Formation chance through 48 hours…low…20 percent.
      * Formation chance through 5 days…high…70 percent.

  • rob b-Truckee/East Bay

    Wow-nobody caught Howard’s latest update (Saturday) with this lil nugget at the end!
    “Longer Range:
    The ECMWF week two and CFS models seem to be trending toward a stronger system moving in from the west, the middle of October that may bring significant snowfall to the high country…”

    • Great Winter of 2017 (SMC)

      I always look for stuff like this in his discussions and I forgot to do that!

    • Bombillo1

      Disappointing that “long range” is now 2 weeks and is as murky as ever.. Meteorology has been beat up the last 2 years, sorry to see…

      • Pfirman

        A little mystery keeps us on our toes. And maybe seat edges.

    • Great Winter of 2017 (SMC)

      Where does he find the week 2 ECMWF?

      • AntiochWx

        I know the “free” version runs out to 10 days, as far as a 2 week version, might have to pony up for that.

    • AlTahoe

      I have been noticing that most model runs show the GOA low setting up around the 2nd week of Oct. This would be a normal progression like we used to see in the pre 2012 years. Then cold fronts should start to work there way down to Norcal out of the mother low. Our first snow is usually around Halloween so this would be a pretty normal progression.

      • Is your ‘groundhog’s (respect here…not a dig) winter forecast still looking okay? It seemed like a rather typical Nina for CA. Norcal down to Central Sierra may do well as far as snow ratios and other precip. The rest of the State might call 85% a victory. Just my guess

        • AlTahoe

          I was going with 425″ of snow for the Donner summit station this winter. Winters that featured a major blocking pattern (like last year) tend to happen in back to back years. Kind of like winters with a major RRR happen in consecutive years. The block usually shifts a little bit from the previous season and I was guessing that it would go further west this year allowing more cold air to come up and over into California. Higher snowfall ratios with less moisture overall.

          I will probably be totally wrong and we will end up getting nothing but tropical AR’s all winter. Lol

          • Wow further west….hmm. I hope so but I don’t see it happening. You’ve been on the money recently so I’m pulling for your forecast. 🙂

          • AlTahoe

            The further west option is purely a wish cast on my part. I have nothing to back that up 🙂

          • Not even a 2160hr run??? :))

      • Pfirman

        The mother low in the Mother Lode?

      • rob b-Truckee/East Bay

        Halloween is usually the target opening for Boreal. Hopefully we see it happen!

        • inclinejj

          Since I’ve been going up to Tahoe regularly late 1970’s, moved there in 1986, I remember Boreal open once top to bottom for Halloween. I think it was either 2005 or 2006.

          • rob b-Truckee/East Bay

            They tend to hit it once every few years, usually one run but enough to generate the press coverage about the opening of the season. Their original plan was to target the 15th but not sure that will be happening.

  • AntiochWx

    Middle to end of Oct does look interesting, would like to see a few more runs of consistency though. Is nice to see the ridge breaking down in the GOA, hope it happens.

    • Tyler Price (Carmel Valley)

      Yeah it’s that pesky subtropical ridge sitting around the desert southwest to a point offshore of SoCal and encompassing the southern half of CA I’m worried about that subtropical ridge is what steers storms more north along the west coast like a deflector over CA especially SoCal.. the Aleutian ridge would be a grea friend for us if it weren’t for that pesky desert southwest ridge in the MR and LR..

      • Pesky = Climatology 🙂

      • SoCal Al (El Monte-SGV)

        That Hadley cell has been our nemesis in SoCal over the last few years, pushing potential fronts/AR’s north and away from us. It seems to develop and strengthen into early-winter, thus our dry weather pattern. Hope things change for us.

        • Dan the Weatherman

          I am hoping that the subtropical Hadley Cell ridge is suppressed to the south more this year.

          • AlTahoe

            I don’t know where to look for the measurements but apparently the Hadley cell has been contracting the last few years. Hopefully that continues.

          • Dan the Weatherman

            I have been seeing the same information about the Hadley Cell contracting recently on another forum.

          • inclinejj
          • AlTahoe

            Found an interesting part in that link. Since we are entering one of the strongest solar minimums in a long time maybe that is why the cell has started shrinking the last couple of years?

            “The hypothesis, that a decline in solar activity reduces the latitudinal
            extent of the Hadley Circulation and decreases mid-latitudinal monsoon
            intensity, is matched by data, showing increased dryness in central west
            Africa and increase in precipitation in temperate zones north.
            Meanwhile, mid-latitudinal storm tracks in the temperate zones increased
            and moved equatorward.[9]”

        • AntiochWx

          It’s going to continue to be our nemesis, the expansion of the Hadley cell is a consequence of AGW. So we just better learn to accept it and hope the El Nino years overperform to get our fill.

  • Thirstier Nick (Santa Maria)

    43 degrees for the low in SMX. Enjoy the fall weather while it lasts. Another Santa Ana-styled Indian summer heat wave breaks out Wednesday-Sunday. What’s it going to take to have a full week of “average” fall weather?

    • thlnk3r

      This is average Fall time weather for this time of year ¯_(?)_/¯

      • AlTahoe

        Seriously why is everybody acting like it is late November and the models are showing nothing but high pressure and heat waves till Christmas?

        • Dan the Weatherman

          That’s a good question. We are just entering offshore wind season for Norcal, and will be so shortly in Socal. It is normal to have dry warm offshore wind-related weather alternating with cooler onshore flow this time of year. I wouldn’t really expect any storm systems until the middle of the month or later.

          • matthew

            Exactly. I spent a good part of my life in the Bay Area and late-Sept/early-Oct we expected one last blast of warm weather.

        • Nathan

          I think because the bags are packed, the windows are shut, and we’re ready to go on a trip but it’s still an hour early to head too the airport.

        • AntiochWx

          Maybe because we are two years removed from a super El Nino, and historically the few years after a strong El Nino are typically dry. The hope is we can squeeze out an average winter before the La Nina takes hold.

    • Thunder98

      Coolest low of the season so far.

  • Great Winter of 2017 (SMC)

    Look at that big winter storm in Montana and Alberta dropping feet of snow! https://uploads.disquscdn.com/images/74af3d1abf29acbe1132f64d4e0b050aecb53732abb83f756b20d2ff7edbb81e.jpg

    • Craig Matthews

      Nice upslope on the Front Range of the Rockies with this one..

    • Bombillo1

      Whew, we’re at 41.02. It sucks to be everyone else.

      • Tuolumne

        If Connecticut’s original land grant had held up you would be just inside the south boundary. Yes, everything between 41 and 42 degrees north latitude across the continent.

        • Bombillo1

          That would have been a pretty unwieldy dimension to control! Strange that would have even been considered.

          • Tuolumne

            A king in England who had no idea what was out there.

      • Yeah something like that. Keep chirping ?

  • DayHoe Herald

    Flew out over Tahoe this morning — looking south, was surprised to see as much high elevation snow as I did — it’s hung tough since that nice little storm — unfortunately didn’t have window seat so couldn’t take a picture

    • Pfirman

      Last flight I took was a couple years ago, to Seattle. Also did not have a window seat, but was on the east side of the plane so figured I could still rubberneck the Cascades. Nope, guy at the window dropped the shade and pulled out his computer. He was wearing a suit and said he took this flight regularly. I could barely contain my disgust.
      Finally, as Hood reared into view I was practically in his lap and he got the message.

  • honzik

    A friend of mine is a photography enthusiast, and posts on his website. I bring it up because he just posted over the weekend beautiful photographs from Hetch Hetchy, which I think, may be of interest to the WW crew.

    https://home.demerjee.com/2017/09/29/a-short-hike-at-hetch-hetchy/

    • Pfirman

      Really fine, thanks. Not sure John Muir would be so happy.

      • honzik

        Yep. They say that this dam is what broke John Muir’s heart. It’s Yosemite valley’s little brother and spectacular in its own right.

    • Bombillo1

      If these photos are recent and the spillway is still spilling and the hydro plant below is going like this picture denotes, now, what did it all look like in March or April? I wonder if DWR is a little nervous about this one? Is that cement getting near the 100 year birthday?

  • Hollow Scene (Riverside)
    • malnino

      We love us some early-fall trekking up to Baldy and thru the Cucamonga Wilderness!! Or the 3 T’s!! Looks pretty clear up there despite the leftover schmaze from the Corona fire, I guess … go out of Icehouse Cyn?

      • Hollow Scene (Riverside)

        Yup, beginning of ice house to the saddle and then to the peak. I wasn’t planning on going all the way but I pushed myself to after other hikers told me how gorgeous the view was. It was my first time out there, I loved it!

    • Nathan

      those are some tough f’in trees.

  • Craig Matthews

    NWS Sacramento Tweet mentioning the possibility of snow showers over Northern Sierra passes Tuesday afternoon/evening with a quick 1-2 inches of snow I-80 south. https://uploads.disquscdn.com/images/b73c3e00baf30d116b521a14449f05cc3941ae6fd919a8b3ee2e418ce758fb9e.png

    • rob b-Truckee/East Bay

      The GFS had been showing a chance of showers off an on the last week or so. Hopefully Cap’n has the camera ready!

    • matthew

      Nothing in the Truckee forecast out of the Reno office.

  • Craig Matthews

    Too bad moisture is lacking and this cold Low is passing through the sacramento valley at night-tonight rather then during the afternoon. But at least this Low is going to bring snow showers to the sierra with a dusting of snow esp where convective snow bands line up and possibly train for a time. https://uploads.disquscdn.com/images/57eacdbda3810e6509f06c4a8009de08d5245278409a39e2cb3b2d454c8108cd.png

    • Pfirman

      We just had two days of strong north wind. If this merely signals a stop to that tomorrow, I am down. Snow on Cap’n, Matthew, Al etc. is just a bonus.

    • AntiochWx

      Kind of an early preview to what I expect. A lot of inland runners with drier than normal precip, but enough to fall in the form of mountain snow.

  • Great Winter of 2017 (SMC)

    Not a breeze here in SMC the last 2 days

  • Great Winter of 2017 (SMC)

    Well we have till November 30 to look at winter storms over California and off the coast on the GOES 16 until it moves to the GOES east position. http://blogs.agu.org/wildwildscience/2017/09/28/new-goes-16-weather-satellite-will-turned-off-14-days/
    Then we will have a shitty angle view of the West Coast and Pacific until the GOES-S launches whenever that will be

    • I think it’s moving 15 degrees. Thanks for the notice I knew it was moving just not when

  • Chowpow

    Nothing says early October like a red flag warning bordering a freeze warning. https://uploads.disquscdn.com/images/876d75b9125dd670d47049f482369fe05aabd09a8d0e10a8c7942e16116ce220.jpg

  • Bombillo1

    http://www.goes.noaa.gov/dml/west/nhem/weus/rb.html

    Wtf? Are the Gods really this funny? Bombillogenisis right over extreme N Cal?

  • Craig Matthews

    Interesting feature developing over Norcal tonight(in Bombillio1’s domain) as a cold upper level Low is developing over the Shasta drainage and northern Sacramento valley out of a vigorous shortwave pivoting down from the nnw on the sw side of a rather elongated trough stretched from ne to sw across the interior NWUS. Appears there is some moisture associated with the developing cold upper level Low(cold for this time of year). This feature bears watching tonight IMO, as satellite shows enhancement of cloud formations around this developing feature over Norcal, particularly the Shasta and Pit river drainages. Though with low dew points in the valley, any showers that develop tonight would likely be light and confined to the Shasta drainage and mtns surrounding the Sacramento Valley, and then, as the Low continues to develop as it moves down the Sacramento Valley, showers would develop in the Northern Sierra by tomorrow morning. IMO tomorrow afternoon could get quite interesting over the Northern Sierra as solar heating enhances lift in the cold/unstable atmosphere, particularly over the mtns, esp the Sierra. I wouldn’t be surprised to hear an isolated report of thundersnow somewhere around the Tahoe area by afternoon. Could see a few showers develop in the foothills as well. Anyway, the lines I drew over the clouds stretched across extreme Norcal is a questionable weak deformation-like zone. It is basically meaningless irt precip so ignore it. https://uploads.disquscdn.com/images/57ee99ed4743702cb6a811920de380daf221ef5965f2b726217557388df102c5.jpg

    • Bombillo1

      I deleted my comment last night about this. Bombillogenesis right over us, the gods do have a sense of humor. Extremely windy, the trees whistling all night, something afoot. The Loop showed it appearing out of nowhere.

      http://www.goes.noaa.gov/dml/west/nhem/weus/rb.html

      • CHeden

        Clearing now in Cottonwood. Winds still howling.

  • 46 here right now.

    • osc3_el cerrito

      48 near the Bay in El Cerrito. Feels nice!

      • jstrahl

        54 for a low in central Berkeley, 55 at 8AM, considerably cooler than the 8AM temp the last several weeks, but still warmer than last year;s readings at this point.

        • AntiochWx

          yeah had 49 this morning, was really nice to finally see some sub 50 lows. Still have to battle through the next week of higher than normal temperatures.

          • Bob G (Gustine)

            Going to warm up over the weekend.

  • CHeden

    Following up on CM’s post, we are indeed under mostly cloudy and blustery conditions here in Cottonwood. Redding apt. is reporting northerly wind gusts to ~40mph, and so far hit 43mph up here on my little hill. With an air temp of 63F, the wind chill is pretty much jacket weather. Radar is showing some likely virga north of Redding, but can’t rule out some light rain is falling north of town.
    Given the local winds, I suspect the mountains will be seeing some additional upsloping winds on the south side of the low as it drops south today…so even though there is a relatively dry air mass still in place, upper level support plus orographics may spark off some Sierra showers later today.

    • AlTahoe

      32F this morning with around a 25mph East wind. The dog walk this morning was very cold. Mittens were required.

  • CHeden

    Once the current CoL ejects out of the area, the GFS has a new low getting pinched off from the mean NE-SW oriented trough off the west coast. The low will then track WSW under a dominant anticyclonic flow to it’s north, eventually becoming part of a well defined Rex Block by next weekend. The low underneath the high is forecast to continue a slow retrograde track, and eventually makes it’s way NNW along the western flank of the high. Once the low “turns the corner” in an up-and-over pattern, the low will weaken the H.P. ridge and the whole mess migrates east. In it’s wake, a more zonal flow should set up, but the jet will stay well north. Here’s the 300mb pattern on the 7th. Hope we don’t see too many of these setups this Winter!

    https://uploads.disquscdn.com/images/34969fb1d040d5800fc204811912ebe1baf9a2b8d635457c0d9edbed0c129727.gif

    • Darin

      When this happens in winter, is it the Snowmageddon setup for the likes of upstate New York?

    • 15N?

      • CHeden

        15N is too far south. The northern ridge ideally would be around 30N, or about 20deg further south than it is now.

    • Craig Matthews

      The fact that that CoL is being rotated anti-cyclonically itself in the eastern NP at that latitude tells of the depth and strength of the anti-cyclonic flow that will be developed for a time in the GOA of the NPac from what I am seein’.

      • CHeden

        Agreed…it’s not good having retrograding activity off the west coast near our latitude….but it is very early in the transition period and a lot can change. It’s not we didn’t have our share of blocks last year…just that they were more favorably located in focusing the jet over California.

    • AntiochWx

      La Nina years general have a more focused area of HP further to the north into the GOA than non La Nina years. It is one of the reasons La Nina years tend to be drier than non La Nina years. Teleconnections during La Nina years suck for prolonged rainfall for central to southern CA. Just hope the HP is further north, might get some undercutting action.

  • tomocean

    47.3F in Auburn this morning. Perfect sleeping weather. I for one, always welcome these final warm days of early autumn. One last chance to get up to high altitudes in the Sierra and enjoy the colors. https://uploads.disquscdn.com/images/b0382a867eb33c5fa3fb7f536d8ac792f0b8985e508d9f8d8e8fd4a65aa6252d.jpg

    • Craig Matthews

      That is a very beautiful shot.

    • cthenn

      Location?

      • tomocean

        That’s in Hope Valley, just to the east of Carson Pass. Last year.

    • Thunderstorm

      Auburn -Above the fog and below the snow.

  • CHeden

    @ tomocean…I wonder how the Fall colors are progressing state-wide?
    Quite a bit of color now along the banks of the Sacramento, but it’s too early down at my elevation for anything more widespread.
    Time fer a day-trip into the hills for some photo ops?

    • tomocean

      There was a good article the other day in the SF Chronicle about the fact that the leaf change is extremely late this year, so there still plenty of time to get up there. I’m hoping to take a trip up to Hope Valley in a few weeks. Here’s a nice map that shows the current leaf state (just click on the ‘View larger map’ icon in the upper right corner.)

      https://www.google.com/maps/d/viewer?mid=12FSQxbVe9CedswOvJaWaeI5vvYU&hl=en_US&ll=37.85374624754116%2C-120.27017115937497&z=7

      • Craig Matthews

        Cool map, thanks

    • Dan weather maniac (ORINDA)

      nothing much to note yet in the Orinda hills. A few crepe myrtles are getting some nice color but thats about it. There are some great Ginko’s, gum trees, mulberry, pepper trees, japanese maples and others on my street that are still generally green, but I will post a few pictures when they turn, usually around mid Nov. We get pretty good color on the street, from non natives generally!

      45 this morning in the yard and noticably chillier even in the city on the walk to work from BART. It feels great!

      • rob b-Truckee/East Bay

        I’ve noticed some of the liquid amber’s starting to change their colors. A few other trees are just doing the annoying green to brown to falling and making a mess in the yard.

    • Thirstier Nick (Santa Maria)

      Foliage is becoming more colorful in Santa Maria recently.

    • cthenn

      I usually do Hope Valley, but this year was thinking of going over to the 395 corridor (Lee Vining, Bishop, and points in between). Our last hiking trip we did was in late September, and even then there were a few Aspens turning. Not sure when the peak color will be, but I’d imagine it’s soon. Hope Valley is usually early/mid October.

  • SoSocal (Chula Vista)
    • rob b-Truckee/East Bay

      I was waiting for someone to post this…figured there was too much partying in the streets of So Cal for someone to take the time to post it.

    • Rose

      What are the chances of this coming to fruition?

      Btw, I’m new here. I don’t know much about weather science at all but stumbled across this forum. I’m intrigued!

      • Bob G (Gustine)

        It is long range. And those storms are pretty unpredictable as to where they will end up traveling. Right now I would say still iffy

        • Rose

          Thanks for your reply. 🙂 What is considered long range? I’ve heard anything beyond day 5, is that right?

      • Who Killed Kenny Strawn?

        IMO, pretty close to zero. The hyperactive Atlantic has put an early end to the EPAC hurricane season. I am expecting a bone dry fall alternating between record heat and chilly weather with the first cold front hitting Southern California around Thanksgiving with very light rain.

    • Nathan

      DAMMIT! I would be out of town that weekend! I always miss this stuff when it hits SD!!!

  • Charlie B

    People are fretting about a dry October. Some historical perspective, based on San Francisco stats (that accurately go back to 1849).
    During the record year of 1861-62 San Francisco received over 49″ of rain for the season. How much in October? None. Thus, October contributed 0% toward that year’s record. I then checked SF rain in October during several epic snow years. (Historical October average is a shade over 1″). 1894: 1.73″. 1889: 7.28″. 1879: .78. 1951: .81. 1937: .9. 1981: 2″. 2010: 1.81. Any discernible pattern?
    During the mid 70’s drought (the one that really raised public awareness of California’s drought susceptibility) October 1975 saw 2.73″ (which was a shocking 34% of that year’s seasonal total) and October 1976 brought .43.
    Since 1849 there have been 14 years with 0.0″ rain in October. Of those, the year end totals averaged 19.54″. Since 1849, there have been an additional 19 years with October totals of less than .10″. Of those, the year end totals averaged 21.76. Historically, San Francisco receives around 23″ near the ocean and 20″ or so inland and near SFO (SFO average is 19.94′). If you mash these together, then years that saw either completely dry or almost completely dry Octobers saw, on the average, about average seasonal rainfall. Of course, some years were really really dry and some really really wet.
    It seems to me that “average” in this part of the world is a number that bears little relationship to what we might expect, or what we will end up with, which was in the past and is now a crap shoot (in my opinion, bolstered by the widely perceived colossal “failure” of seasonal models in the past couple of years…by this time last year Daniel had two blog posts already out “predicting” a dry winter with little chance of drought relief) .

    • Dan weather maniac (ORINDA)

      Fantastic post, and I 100% agree! That said I cant wait to see the first front roll off the pacific!

    • AntiochWx

      The main problem with this is 0″ in October in the year 2017 means more than it did before the big El Nino in the late 1990s. The climate state is much different now, we now have to worry about the persistent ridging and a further north jetstream, especially during La Nina years.

      • jstrahl

        You think there wasn’t persistent ridging in those other Octobers?

        • AntiochWx

          Sure, but persistent ridging takes on a whole new meaning now. We are talking RRRs, and climate aided extremes. Natural progressions aren’t the same anymore. Jet stream is further north than normal in a lot of winters now a days, which makes it even harder for precip to persist in already dry weather patterns aka La Nina.

          • jstrahl

            A lot of winters? You are talking about a period of five years. Just like ’86-92. You again are arguing everything is different while using the past to predict the future. I think you are doggedly determined that this is gonna be a dry year. Or else think that by saying that over and over, it will turn out wet. 🙂

          • AntiochWx

            I’m fairly confident what we have experienced during the RRR years will become the new normal, especially during atmospherically condusive conditions for drier than normal weather during La Nina years. Heck even neutral conditions will have drier than expected outcomes. Our main hope will come down to persistent troughing patterns during El Nino years, or quit hitters during Neutral years. The expansion of the Hadley cell is going to cause a lot of problems in the near future for California.

          • jstrahl

            As others have posted here, that Hadley cell is actually contracting, but who cares about facts?! Not to mention studies, including one Daniel was involved in, showing there will be more dry years but also more wet ones, resiling in average rainfall staying the same or possibly (per a study Daniel was not involved in) in increased overall rainfall. Have fun stewing. This is too far back in the discussion for me to engage in any more.

    • Bob G (Gustine)

      I agree. October means little to me. Especially the first half of October. Is a transition month.

    • jstrahl

      Plus, 0.))in October ’77, before the drought busting drenching rest-of-season, very dry October ’94 before a HUGE season, bone dry (.10 inches) October and a whole T in November to begin a very wet ’95-6., fairly dry October and below average November to begin 2005-6.

      • AntiochWx

        All those years were either in the warm phase of the ENSO or direcly coming off the warm phase. Usually year after a weak-strong Nino will carry wetter conditions. None of those years were 2 or 3 years removed from the El Nino heading into a La Nina.

        • jstrahl

          Really? Which warm ENSO preceded October ’77? October ’94? And what about the WET October preceding ’75-6? In addition, you’re trying to both have your cake and eat it too, claiming that everything is different but at the same time using (alleged) past results. I myself don’t know what’s gonna happen. Given the huge changes in the polar regions, i think that past patterns are pretty much useless for predicting the future.

          • AntiochWx

            January 77′ was unofficially a weak El Nino that was just coming off a 73-76′ La Nina. October 94′ was coming off a weak El Nino 93′ and a strong El Nino 91-92′ , which never went into cool anomalies before October 94′ . October of 75′ was wet, but it was in the heart of a La Nina, and the rest of the year turned out to be bone dry. The wet October of 72′ was because of the strong El Nino. Everything is beginning to become different, but there is still an underlying trend in atmospheric variability under AGW. I don’t forecast only on the past, I blend the past analogs with future AGW stagnation in mind. AGW will make La Ninas drier and El Ninos possibly wetter, which is why I’m really concerned about this upcoming year, and especially 2018-2019 being drier than normal.

          • jstrahl

            So, El Nino 2015-16 was really wet, right? Grasping at straws.

          • AntiochWx

            This is the first very strong El Nino to behave this way, I guess one could argue it took the atmosphere a full year to respond to the very warm SSTs, or one could argue hopefully this isn’t a sign of an underproducing El Nino compared to the other very strong El Ninos going forward. I guess we are going to have to agree to disagree. Some think our long term rainfall may increase, I’m a firm believer the long term trend will decrease, The Hadley cell maybe contracting in the short term, but as long as AGW is influencing the weakening of the polar cell via warming, the Hadley cell will continue to expand, and an expanding Hadley cell spells longterm drying, especially for SoCal.

          • jstrahl

            “ome think our long term rainfall may increase, I’m a firm believer the long term trend will decrease”
            I posted links to a recent (3 months ago) study much further towards the top. If you have contentions with that study (i.e. methodology, bad record of the scientists involved,…..) i’d like to know, seriously. Up in that post. not here please. 🙂 And what AGW is doing is melting the ice cap, which means flows become much more varied and unpredictable, at the global level. No telling what this does as the melting proceeds, especially with Antarctica now melting as well.

  • mattzweck

    Typical day here in the high desert Lancaster area. nice in 70s . Partly cloudy. And windy.

  • Fairweathercactus

    Looks like we will be shut out of any real rain for the first half of this month unless you trust in that crazy 12z. I think October might go in the books for most parts of So Cal with the big old 0.00.That should aid to the cold and dry winter I am expecting.

    • Dan the Weatherman

      I don’t know whether the entire month will be shut out, but I believe it will be dry during the first half of the month. We will probably have a Santa Ana wind event within the next week or two for our first widespread event of the season.

    • Thirstier Nick (Santa Maria)

      You’re 20 days early to call it.

    • AntiochWx

      I’m thinking along the same lines cactus. Cold dry from San Simeon and points south, San Simeon and points north below to average. Tahoe and north Mountains will see above to slightly above snowfall. Thinking 17-21″ inches of rainfall for SFO.

    • Hollow Scene (Riverside)

      I think it would be more normal if SoCal is dry the first half of October. I can remember a few times where the first rain was right at the end of the month!

    • BRP (Ventura)

      Hey “Killjoy”, just because you live in an area that has an average annual precip total of 6.0″, and are used to 340 days of sunshine a year, quit trying to make us in desperate need of rain pissed off with your “Fairweather” procrastinations! Thanks!

      • AntiochWx

        If being a realist pisses off people, then I don’t know what to say. If patterns are conducive for a wet pattern, I will say it. We are heading into a La Nina, hard to get high hopes for that just alone.

    • happ [Los Angeles]

      I did enjoy drizzle this morning but October is not a wet month for us. Do SST [near 70] play a role at all?

  • CHeden

    As I’ve been mentioning for over week or so, the GFS continues to struggle with the evolution and track of a TS moving our way out of the ITCZ.
    As a couple of other posters just noted below, this time the GFS is putting far SoCal in the crosshairs. Note that this is not the first time a similar solution has popped up, but it is a little more within the SR/MR forecast period instead of out in Fantasy Land. Let’s see if any consistency at all emerges over the next 3-4 runs. https://uploads.disquscdn.com/images/0dfb687e119b2938529f3a0cee6e945d10ed4dd821cc3f7e3fd086e185b2b155.gif

    • You’re suggesting 10 days and not 16 day total posted, right?

    • molbiol

      Checked the ensembles and there is zero support for this solution. Also the operational CMC has nothing resembling this and instead has split flow across the NPAC N-america teleconnection. The Euro also votes ‘No’ on any tropical system even coming close to Socal (or developing); it instead has the first major deep fall-like trough of the season impacting the (gasp!!) upper midwest with strong ridging across the west coast. Enjoy the warm fall weather. October is especially nice here in Lancaster with crystal clear skies, warm temps and little wind.

      • Great Winter of 2017 (SMC)

        Euro and CMC suck for the EPac, CMC is bad overall for all TC’s

  • happ [Los Angeles]
    • AntiochWx

      It was hot, that is why I was laughing when some people continuously were understating the veracity of the summer temp anomalies and calling it typical summer time heat. Hottest summer on record for quite a few locations.

    • I’m curious to see what JAS when the September update is available.

      • AntiochWx

        Going to be warm, really warm. Wouldn’t be surprised to see JAS as top 10 warmest in California.

  • Hoping the next damn 6hr run will fulfil one’s subjective sign of a very wet winter is now the official definition of insanity.

    • molbiol

      Summer ended only two weeks ago. We are three days into October. Everybody calm down 😉

      • molbiol

        Also, given recent events, remember that life is short, precious, and unpredictable. Try to make the most of it-Seriously

      • SloTruckeeJohn

        This is what we do on this site. There’s no calming down until it is coming down!

    • Nathan

      ….is anyone actually doing this?

  • SoCal Al (El Monte-SGV)

    According to the latest GFS 12z, Friday the 13th will be a day of “good luck” for us here in SoCal.

  • Cap’n

    While we wait for the GFS wrist slashers hotline to be linked to the blog, might as well enjoy a little dark blue lurking around the Sonora Pass area. I’m camping at Leavitt Meadows this weekend, glad it’s moving through now. It’s brisk and the clouds are forming here near the crest but I’m not counting on that little blue blob to make it here.

    https://uploads.disquscdn.com/images/4dcf95f2e71971c08fe71f61867d0fea897d14176165190b8003e381c27e4f01.png

    • SloTruckeeJohn

      Do you remember that fishing spot I told you about last spring? This could be a killer time to hike in there for a slaying! I’ll be up there in 3 weeks.

      • Cap’n

        I do remember that, and thanks! I haven’t fished for years (not that I was ever that experienced) and although I was contemplating throwing out a line earlier this year, it hasn’t happened. This camping trip is a hiking one, so your secret fishing spot is safe from my invasion for now!

  • Taz & Storm Master

    getting some vary strong out flow winds right now

  • Charlie B

    October is the wettest month, by far, in SE Alaska. Juneau, Yakutat and Ketchikan all have twice as much precipitation in October as they have in March.
    November is the wettest month in BC and most of Washington state.
    December is the wettest month of the year in Oregon (Portland and Eugene, for instance).
    January is the wettest month in most of California (outside of SE deserts), although a few places in the south average slightly more in February than January.
    This shows the tendency of the jet to sag south as winter sets in and takes hold.

  • AlTahoe

    Check out the Temp anomalies for January 1949!. I was always fascinated by this event so i decided to run the maps. I can’t find any other cold snap that encompassed so much of the West. Really a phenomenal event https://uploads.disquscdn.com/images/9e3dadf7dccb1c4c0fa3d985bf7977b3a2e803019be91b6b12efc1d93d3bcf87.jpg

    • AlTahoe

      Actually January 1937 was very similar. Weird that it happened twice in a 15 year period and then never again. Must have been some huge blocking/wavy jet stream back in that 1930’s – 1940’s period. https://uploads.disquscdn.com/images/45dfca768cf13c13ada20e3f87ce9a1d523f88adb9eda5e57575c50aa4e2dcf9.jpg

    • Thirstier Nick (Santa Maria)

      According to WU’s city history, Santa Maria had a rare snowfall at that time. Quite a polar vortex in the West.

    • Great Winter of 2017 (SMC)

      I’m almost sure I remember hearing about snow here that year, I know the last snow here in SC was 1976 and we’ve had many instances in the past where there’s always been a slight chance of snow here. Once a year we usually get snow levels down to 2,000 feet in the Bay Area, anybody remember in January when the Santa Lucia’s were hit with feet of snow?

      • Craig Matthews

        Which January was that? I can remember a few in the 1980’s and one in 1993 that dropped about 2 feet of snow on Anderson Pk before it all changed to rain.

        • Great Winter of 2017 (SMC)

          This January

      • Tuolumne

        Early 1974 for sure, not to exclude other years. That event also caused a huge snowfall in the Santa Cruz Mountains.

    • Nate
      • Cap’n

        John Fante has a great short story about that winter.

    • AntiochWx

      Would be nice to experience that kind of cold snap, when was the last time we have seen snow near the bay?

      • AlTahoe

        We had snow in downtown San Jose twice between 2003-2008 not sure what years though. 89 and 90 featured back to back snowfalls in Morgan Hill.

        • AntiochWx

          Yeah would be nice to see. I just hope the pattern is conducive sooner rather than later. Before AGW makes it even harder. Low level snow was already rare, now its going be even rarer. What was once a 2 or 3STD event probably becomes a 4STD event.

        • AlTahoe

          Also in 1998 i remember an actual snow squall line came through Morgan Hill from the east over Henry coe park. We picked up a quick inch of snow in about 15 minutes and there was actually blowing snow. My grandparents house in Madera picked up 2-3″ from the same event. This event was very localized though as the moisture was just over Morgan Hill. San Jose got nothing in that one

          • Craig Matthews

            Was that on Christmas Day? It snowed huge silver dollar size flakes on my deck at 1750ft on Christmas Day 1988 in Big Sur. Unfortunately it stopped snowing right when it began to accumulate.

        • Craig Matthews

          We had snow in Big Sur in early February 1989. It snowed in the form of convective graupel showers rotating inland off the ocean, which produced minimal accumulations down to sea level where the heavier showers occurred. This event may have been the one that brought 1/4″ accumulations of graupel on the golf courses at the AT&T golf tournament one morning which caused a delay in the tournament. In mid-late Dec 1990 we had graupel snow showers that brought very minimal accumulations down to sea level as well. For some odd reason my area along the Big Sur Coast got missed by the snow showers that came down the coast. But areas that did get hit by those showers dropping down the coast picked up minor accumulations at sea level. The Dec 1990 event was followed by a week of near record low temps that killed many small Eucolyptus trees in the canyon bottoms around Big Sur.

        • Great Winter of 2017 (SMC)

          I guess San Caelos has really missed out on snow events in the 80s, 90s and 2000s, never knew that

        • e e

          March 2006. Thundersnow north of Waldo Tunnel. I-280 between San Carlos and Redwood City was closed for a few hours due to brief blizzard conditions.

    • Craig Matthews

      I’ve actually been thinking that this winter we are going to experience a record cold snap out west, with near record breaking snowfall at very low elevations and areas near sea level in Ca. Just look at what has happened irt weather extremes in South America this last year. Take Santiago Chile for instance, where record breaking heat wave occurred in mid December 2016, followed by near record cold and a snowstorm in Santiago Chile in mid July 2017. Santiago happens to be at the same latitude as Orange County CA. Not saying our weather correlates closely to Chile but it is interesting all the same. Here’s some links, sure hope they work….

      Link on the Chilean heatwave: htttp://santiagotimes.cl/2016/12/15/chilean-heat-wave-breaks-record-temperature-set-a-century-ago/

      Link on the Santiago Chilean snowstorm: https://www.washingtonpost.com/news/capital-weatther-gang/wp/2017/7/17/photos-santiago-chile-saw-most-snow-in-decades

      • Thunderstorm

        1972 would be hard to beat for cold. Lasted 18 days. 1990 was also cold but did not last as long. Killed the Eucalyptus trees foliage everywhere. Big fire hazard. 1961 was the biggest snow I remember 3 inches in Menlo Park.

        • Craig Matthews

          Yep snowed on my birthday December 6th 1972 that year though I barely remember it as I was only 18 inches tall back then. Dec ’72 holds a lot of records for cold across Norcal.

  • molbiol
    • Great Winter of 2017 (SMC)

      Was looking very fishy down there in the models and the SST’s in that area are significantly warmer than they were in 2005, that gyre will sure help its development

  • Great Winter of 2017 (SMC)

    Hoping this will be the year we get our average number of days at or below freezing, usually this happens when Tahoe gets near 0. First freeze is usually by November 15 and we haven’t freezed once since atleast 2013.

    • AntiochWx

      Better hope we get some freezes by the end of this decade and enjoy it, its going to be very difficult the farther we get into AGW.

  • Craig Matthews

    Looks like an outflow boundary is making its way out of the foothills into the
    Sacramento area, with the middle part of the outflow appears to be weakening as it is making its way toward the Delta. Convection appears to be forming on the north and south end of the outflow, with convection occurring near the s Motherload and central foothills. In the are I circled, I think there will be a descent dusting of snow in certain places where bands of precip form and train along the east side of the Sierra crest where some upslope occurs this evening and night. Looks like a dusting of snow is also possible in the Sweetwater Range and possibly White Mtns this evening and night as the Low over central Ca brings a mid and upper level southerly flow to the central Sierra along with an upslope flow on the east side of the crest that will be spreading east into NV as the Low begins to move ne. Will be interesting to see how the mountains look by tomorrow morning if clouds clear. https://uploads.disquscdn.com/images/c6f29429091b8a5674224520b767a37a41e04508b2fe73d2baafc0ce4a1d8531.jpg

    • CHeden

      Good call! The daytime heating is just enough.

      • Craig Matthews

        Thanks. Will likely see a decline in action once the sun goes down, tho its possible bands of precip could keep going overnight in upslope flow east of the central Sierra crest and northeast over NV as the Low moves up thatta way IMHO.

        • CHeden

          BTW, this morning’s call on the CoL dropping down from the north was spot on. Another high five from here.

          • Craig Matthews

            Thanks. That means a lot coming from you!

  • Great Winter of 2017 (SMC)

    Thought I share a photo of Crater Lake from 7/24, a much different scene from this pic now that we are in the early Fall. https://uploads.disquscdn.com/images/59148c2c91ca97a124f6bff299f740516db86558cc770d49e99c6472478989e0.jpg

  • AntiochWx

    Fun fact! Did you know the 1861-1862 record rain year of 49.27″ in SF also had an October of 0.00″ . One can dream right? Lol

    • Great Winter of 2017 (SMC)

      The return of the ARKSTORM is coming this year after a usual absence of 150+ years! ?

      • AntiochWx

        I wonder what the ENSO state was for that year. I highly doubt it happened during the cold phase.

        • CHeden

          Keep in mind, in 1862 the planet was still in recovery mode after The LIttle Ice Age. The base state (equilibrated) of the atmosphere was radically different then vs. now.

          • AntiochWx

            Right, which is one of the reasons we won’t fully know what atmospheric conditions aided the extreme pattern.

          • ben

            The sediment records off of santa barbara indicate that the 1862 flood was a small one. It could be that socal missed out on the serious action that year, or that the 250 year storm season is apocolyptic.

          • Pfirman

            Wiki differs from your report ben.

            The plains of Los Angeles County, at the time a marshy area with many
            small lakes and several meandering streams from the mountains, were
            extensively flooded, and much of the agricultural development that lay
            along the rivers was ruined. In most of the lower areas, small
            settlements were submerged. These flooded areas formed into a large lake
            system with many small streams. A few more powerful currents cut
            channels across the plain and carried the runoff to the sea.

            In Los Angeles County, (including what is now Orange County) the flooding Santa Ana River created an inland sea lasting about three weeks with water standing 4 feet (1.2 m) deep up to 4 miles (6 km) from the river.[15] In February 1862, the Los Angeles, San Gabriel, and Santa Ana Rivers merged. Government surveys at the time indicated that a solid expanse of water covered the area from Signal Hill to Huntington Beach, a distance of approximately 18 miles (29 km).[21]:38

            At Santa Barbara County, the narrow coastal plains were flooded by the rivers coming out of the mountains. The San Buenaventura Mission Aqueduct that was still drawing water from a tributary of the Ventura River for the town of Ventura water system, was abandoned due to the damage in the area that become the separate Ventura County in 1873.[22]

            In San Bernardino County, all the fertile riverside fields and all but the church and one house of the New Mexican colony of Agua Mansa,
            were swept away by the Santa Ana River, which overflowed its banks.
            Father Borgotta ringing the church bell on the night of January 22,
            1862, alerted the inhabitants to the approach of the flood, and all
            escaped.[23]

            In San Diego, a storm at sea backed up the flood water running into the bay from the San Diego River, resulting in a new river channel cut into San Diego Harbor.
            The continuous heavy downpour also changed the look of the land, the
            previously rounded hills were extensively cut by gulleys and canyons.[21]

          • ben

            I was talking about the varved sediments offshore sb that go back thousands of years. The 1862 deposit is a fraction of the thickness of the majority of the large flood deposits which have a recurance interval of around 250 years. Im not disputing that its the largest flood modern ca has seen, just that much larger events are not just possible, but likely.

          • Pfirman

            Agree totally. Even in San Francisco Bay 1862 is basically not even a blip.

          • Pfirman

            Forgot to ask what ‘varved’ means to you.

          • ben

            Varves are laminations in sediments indicating annual changes in deposition and can be used to date a deposit by counting the varves, much like tree rings.

    • jstrahl

      I think someone told you that earlier today, right here/ 🙂 (Charlie B).

  • AntiochWx

    Whatever you do, don’t look at the CFSv2 anomaly maps for Jan and Feb. Cringe!

    • jstrahl

      Indeed. I remember how well they worked out last year. 🙂

    • Cap’n

      WW crisis center hotline should be attached?

    • Always assume the opposite of those.

      • AntiochWx

        Hope so, some of what they are depicting would be horrific.

    • Dan the Weatherman

      I wouldn’t trust the CFSv2 for any long range prediction! It has been wrong more times than I can count on the fingers of my hands in recent years.

      • AntiochWx

        I don’t really trust or rely on them for my individual forecast, it’s more for entertaining purposes only. I do often wonder what their verification scores are.

        • V1 may have been better than V2 but V2 started about the time of the RRR and sudden warming of the NP. Just a pre coffee thought of mine this morning

    • I’m waiting for CanSIPS. I think this model gets much better initialization data. October’s run should be out soon.

  • Tan

    Its fascinating to read these comments. I am very interested in Meteorology and these models. Where do I start reading?

  • Who Killed Kenny Strawn?

    Don’t look at the 00 run of the GFS

    • AntiochWx

      puff puff pass. At least the trend is there for the GOA Low at the end of the run. Just gotta fight off the SW ridge now.

      • Who Killed Kenny Strawn?

        Actually the GFS has something that would be believable if it was September of 2015 but it’s not. There is no way that model run could come to fruition this time of this year.

        • celo

          Water too cold?

          • Who Killed Kenny Strawn?

            Yep and also the pattern of La Nina vs. El Nino. It looks kinda of similar to the remnants of Hurricane Linda or Dolores.

    • Nathan

      Ridge beast mode

      • Tuolumne

        Where’s our RRT?

        • Bombillo1

          Notwithstanding Charlie B’s nice statistical research, what is happening now does not portend well for water. For us in extreme N Cal a modest rain (.75 inch) in September would be entirely normal. By mid October it should be game on with some kind of event every 7 days or so. Firewood should be laid up, heavy equipment work finished ( by law on Oct 15th), basically no more outdoor work. These anecdotal milestones have not been reached and the upper atmospheric conditions are concurring. Daniel’s disparaging outlook post from last year should get the mothballs removed and reprinted.

    • Thirstier Nick (Santa Maria)

      Thanks for the warning. If that’s true, October will be roasting as toasted pumpkin seeds.

  • Boiio

    Noticed a few contributors on here discussing low snow events. Thought I’d share this excerpt from The Marin Journal in 1922. “THE MARIN JOURNAL. VOL. LXI. NO. 5. SAN RAFAEL, CALIFORNIA THURSDAY. FEBRUARY 2. 1922 Snow Fall Covers Southern Marin Snow came Saturday night and cov•ered fully half of Marin county in a •deep blanket of white. Mount Tamalpais lay beneath a ?coating that near the peak reached a -depth of three feet. By a queer freak of atmospheric influence the snow fell heaviest in the area from Novato south to Sausalito and from the Northwestern Pacific railroad to the -coast. San Rafael hill was covered to a depth of from 3 to 6 inches, and scores •of people ascended the Boyd Memorial Par’: trail to enjoy sports which only the snow can make possible. Snow men were shiveringly built in many par’s of town by reddended little hands that were experiencing their first contact with the fluffy building material. San Anselmo and Fairfax were favored by a heavy fall, and it is reported that on White’s Hill the depth measti’ed 24 inches.”

    http://contentdm.marinlibrary.org/digital/collection/NPMJ/id/11022

    • molbiol

      Here is the upper 500mb pattern for that event. Note the very low 500mb heights across California. Temps in Downtown Los Angeles stayed in the upper 30s with heavy rain and brisk east wind according to reports. Here in Lancaster, at least a foot and a half of snow fell. Snow levels were low enough to impact the lower foothills

      https://uploads.disquscdn.com/images/1030a97fdc07defa610ef0dc2b52abc8c9fbcaeded7bb3095f890f75a1e1ff07.jpg

      • Dan the Weatherman

        From looking at the map above, the winds in Los Angeles were more likely out of the west and northwest as opposed to the east, as the flow was solidly onshore with the low centered over NW Nevada and NE California.

      • Craig Matthews

        I really like this type of reanalysis map because it includes actual values irt 500mb heights, 500-1000thinckness and MSLP . Am wondering where you got this from, if you don’t mind?…esrl interactive plotting site?

        • molbiol

          I like both esrl and meteocentre (the site that hosts runs of the GEM/CMC..

    • Great Winter of 2017 (SMC)

      Hopefully it’s still possible for event like that to happen

    • Thor

      wow. 2 feet of snow on Marin’s hills. Hard to fathom. Thanks for sharing.

  • Craig Matthews

    Offshore wind season may begin early next week, with the possibility of very strong offshore winds especially across Norcal. Look at how tight those isobars are, esp across Norcal and Sierra Sunday night. https://uploads.disquscdn.com/images/2ed83d00d922c7282817c4b476cf3cf3bf149cb5e95a2db2490decd73ca4a257.png

  • Thirstier Nick (Santa Maria)

    Looking at the latest SST anomalies, I’m pondering about this orange blob that has developed over the summer west of California that looks like ridge fuel. If recent storm-blocking blobs are bad omens, it’s not a good sign for winter rain fanatics in the Southwest. We’ll see what happens.

    • AntiochWx

      I find it more troubling that we were just under an anomalous cold ULL for this time of year, and we only managed to be 2 degrees below average. It takes more and more colder trough patterns just to get to slightly below temperatures.

      • AlTahoe

        There is very little cold air to work with this early in the year. Plus the cold has been mainly centered over the Sierra. We have had like 5 days already with highs 20F below normal. I haven’t had to use my heater this much so early in the year before. It is currently 27F out tbis morning

        • Cap’n

          NOAA showing the airport at 19F. I’m at 25F over here. Agreed, I’ve been burning wood almost daily for nearly three weeks now.

        • matthew

          Truckee airport reporting 19F this morning, about 10 below our average for October. On the bright side, Fall colors should be awesome for hiking this weekend.

          • AlTahoe

            Yep planning on getting some photos from hope valley on Saturday

          • Cap’n

            We hiked Tinker Knob from Coldstream Canyon on Sunday, the aspen groves back there are beautiful.

          • matthew

            We are planning Marlette Lake this weekend.

          • Cap’n

            Nice, I rode there via Flume a couple weeks ago, trees were barely starting to turn, should be great now. 89 is in better shape now for road biking.

          • matthew

            Thanks for the info on 89. Probably do the loop next week if the weather cooperates. Gotta get myself psych’d up for 50 miles in the saddle first…

        • AntiochWx

          There is enough cold air to work with. There was -8 to even -10C anomalies showing up in the 850hPa level. That should be enough to get some decent cooling in the lower elevations, but most areas in the bay were -2 to -5F departures, and only for one day. Not saying higher elevations weren’t much cooler than normal, it’s just lower elevations especially near the bay is getting harder and harder to get an extended colder anomalies, and need more extreme dynamics to reach those numbers. I’ve watched numerous times over the last few years, even with a average 850hPa setup, we always get 1-3F positive departures.

    • jstrahl

      Ridges are far more likely to create blobs than vice versa.

      • PRCountyNative

        Agree, based on observation. SST’s follow, more than they lead.

        • CHeden

          I concur as well. Seems like SST’s lag both the winds and cloud cover in the initial stages. Then, self-reinforcing takes over and everything becomes tightly linked.

  • Great Winter of 2017 (SMC)

    https://twitter.com/weathernation/status/915580276637618176 Just what we need, this TC has lots of extremely hot water, up to the upper 80s work with. This is the next one to watch for the US.
    Just a heads up, the GFS is not useful for this TC currently

  • CHeden

    Dovetailing onto molbiol’ re-analysis post on the setup in1922, here’s a few more notable examples of NorCal cold/snow events.
    Note all examples had a NE-SW trough that was the source of the cold air (continental in origin).
    Regular Wx watchers of the current patterns will instantly recognize the similarities we’re seeing already this year to these unusual cold air events.
    Assuming what we’re seeing today is indeed the developing (synoptic) west coast flow pattern, a continuation of periodic NE-SW troughs are likely to bring at least one or more very cold incursions into California later this Fall and Winter. While I think the flow pattern may indeed continue it’s current trend and evolve in this general direction, I still question how much/how cold the air will actually be around by the time it makes it into California. We shall see.

    1st image: 1972, first week in December featured the coldest period in my lifetime in the Bay Area. Massive, long lasting freeze(s) ocurred, which killed huge areas of cold-intolerant plants and animals (local iceplant in particular was devastated. Lows in isloated spots in the immediate area plunged to ~ 13F as I recall.
    2nd image is from the last of the bona-fide snowfalls in/around the Bay Area. The low associated with snow/hail falling down to sea level near SFO was very convective as the initial CF marched in from the NE. On ECR near Millbrae, we had 1/2 hr. of thunder + snow/hail around 6 p.m. Snow fell to the ocean edge north of the Golden Gate, plus the top of Angel Island got a nice dusting.
    The last image is from Jan 21, 1962, and is one of the most important days of solidifying my fascination with weather. Early in the morning, a cold low came down over our place in the hills above San Bruno, and after dropping hail around 3 a.m., the precip turned to snow, leaving almost 3″ on the ground. This was the first time I had even seen snow, let alone made a snowball. The snowman my brother and I made lasted over two days. I think what I remember most was the smell of the snow plus smoke from the fireplaces all over the neighborhood and the eerily calm conditions. From then on, the smell of snowfall became one of my favorite enjoyments whenever I see some.

    https://uploads.disquscdn.com/images/d4380bce001cf0da7b1d16d97cb46993d74a95a1276db72935bac14178e0fed0.gif
    https://uploads.disquscdn.com/images/d93670d28c00a892d7c60d0fa7ced26957cd7eeb08b1495134805cdeb329b71f.gif https://uploads.disquscdn.com/images/f3505da499296c45a46bef1b12e1c6e01671ece598cf46c46f8d130eb1c14000.gif

    • rob b-Truckee/East Bay

      The 72 snowfall was before my time, but I have heard stories about it form my parents. I also recall there was a snowfall in the Bay Area that was significant around 1976 too? Other than that the cold outbreak around Dec 1990 sticks out as well.

      I feel bad I’ve noticed the smell of snow….but I know what you mean on the fireplaces. Not something you smell in the Bay Area much anymore (BAAQMD laws) but still prevalent around the Tahoe/Truckee area during the winter.

    • CHeden

      Note the similarities in the NE-SW troughing from today’s initialization to the historical cold air patterns/events I noted above. https://uploads.disquscdn.com/images/a4ab92df742f6e6f85ffdc2debde23042baaaf9703c7a436c0f24ba951040fec.png

      • AlTahoe

        That high west of the Aleutians is where I thought it would setup this winter. As that high pressure ebbs and flows through the winter I would expect some decent cold air shots to make it into California.

        • AntiochWx

          As long as the average position of the HP stays closer to the islands, and not over the GOA, I like our chances of some nice cold shots. La Niña just adds to the increased probability.

          • CHeden

            Uhmmm, note that in virtually all of the re-analysis’ we’ve been posting, the common thread is a highly amplified HP ridge that’s nosing into/BC/western Canada. It’s the anticyclonic flow coming down the ENE flank of the high that’s pulling down the frigid continental trough into/over California. So, if you want the REALLY cold air, then you’ll have to contend with a H.P. ridge hanging overhead.

          • AntiochWx

            Right, but I’m willing to sacrifice the really cold air if it means the average HP is closer to the islands as to not rob us of moisture. Not a fan of dry cold, rather have moist cold.

          • AlTahoe

            Yeah I am aiming for a slightly wetter and less frigid winter than those ones. The really cold winters tend to be dry. I am thinking along the lines of good snow events were heavy accumulations start at about the 3-4k level. Like Dec 1996, Jan 2008 ect

          • CHeden

            Gotcha.
            Hope yer right. Prolonged 30’s is not my cup of tea (unless there’s a couple of inches of snow on the ground!).

        • CHeden

          IMHO, the H.P. now NE of Hawaii will be the bigger player in determining our west coast weather pattern.

          • AlTahoe

            I think the cut off low that is wondering around out in that region is pumping the ridge up in a bunch of weird locations. I will revisit it a week once that pesky thing is gone 🙂

          • CHeden

            You mean “if” it’s gone…and whether it’s a phoenix-type of system.

    • Chris

      What is so noteworthy to me is that the freeze in 1972 occurred in EARLY December.
      What if this pattern set up several weeks to a month later when the arctic would be much colder!
      If the jet stream is indeed trending towards more north/south orientations, I would suspect that more arctic air masses from the NE would descend upon California more frequently.
      Any others have thoughts to add to that?

      • CHeden

        I think that’s the jist of what these recent threads are implying.
        Many of us have been seeing repeated signatures of NE-SW troughiness, which in past events, can be correlated with anomalous cold snaps/snow.

    • molbiol

      In a couple of those cases, the Aleutian block isn’t in the typical position that you would expect for these types of patterns…but it is still a prominent feature of all of these outbreaks

    • Dan the Weatherman

      It is amazing that the entire weather pattern nationwide was almost identical in these cold air outbreak setups, especially with 1962 and 1976.

  • Charlie B

    Long range (seasonal) model warning.
    Continuing on my theme of the past few days, I take early season signals (whether anecdotal or model based) with a grain of salt (and perhaps an entire salt shaker). It is now early October, and Daniel is probably (hopefully) working on a seasonal outlook post. Consider these posts from last year:
    AUGUST 23, 2016. Early indications not encouraging for drought relief this winter. The set up depicted my seasonal models is characterized by persistent west coast ridging that is a fair bit like the RRR pattern and is similar to the kind of atmospheric pattern we have seen more frequently in recent decades.
    SEPTEMBER 18, 2016. “The blob” returns to the north Pacific. The jury is still out re the winter outlook, with some indications of enhanced west coast ridging.
    OCTOBER 25, 2016. “Unusually active October continues across California; but winter doesn’t look so promising.” Latest data regarding coming winter not encouraging for California. Ensembles hinting at a warm winter with the potential for a “north wet/dry south” split.) Other models are showing a widespread dryness that looks “eerily familiar.” Overall, conditions “suggest that we are still likely to be talking about the ongoing California drought well into 2017.”
    NOVEMBER 20, 2017. Dry continues to be depicted by seasonal models for December-March.”
    I still do believe in the law of average. What “is” average is an open question as we move forward in a land that “average” is only a number with wild departures toward super wet and hyper dry. Think about it: When was the last time we really had an “average” year. My take (from a Reno perspective) on the last few years? 2009-10 pretty good and maybe the closest to average. 2010-11 was a top ten snow year. 2011-12 dry with some decent late season storms. 2012-13 wet early, really dry later. 2013-14 really really dry. 2014-15 worst snow year ever (but December was really wet but it did not translate into any snow to speak of). That was also the year that the east coast experienced a brutal winter with record snowfall in major cities such as Boston, which received 108.6 inches of snow, and that was far more than most Lake Tahoe/Truckee locations, and not all that far behind Donner Summit). 2015-16 el foldo for the south; near “average” in the north in terms of precip, but warm for temperatures. 2016-17…wettest ever for the north; reasonably wet for south, very warm with relatively high snow levels (but boy, what a snow year it was in those higher elevations.)
    Average? What is it? I doubt that last year was anything other than an historical anomaly. I suspect (hope beyond hope) that the extended 4 year drought was an historical anomaly as well, and that we are not slipping into a decade or even multi-century long mega drought was this area apparently experienced in the distant past.
    So, what is my take on the upcoming winter? slkdghangeggvfsksk83884@@!!

    • rob b-Truckee/East Bay

      I tend to agree Charlie, we look at the water years in our lifetimes….most people really only look back 10 to maybe 20 years of winters. When in reality we’re talking about thousands of years. So the average can be totally different if you’re 20 yrs old versus if your 70 years old. We only know what we read about in history books or see in pictures. But beyond that it’s all based on research on what they think happened. Much like you I’d think we’re bound for a few average winters and some cold snaps…beyond what we normally call “Cold” in the winter. Last severe cold snap I remember for the area was 1990.

      • AlTahoe

        I think Dec 1998 had a cold spell very similar to the Dec 1990 one and the only reason why it doesn’t show up is because it happened on the same exact days as the 1990 one. Some places broke their minimum records from 1990 but a lot of places were 1-3F degrees warmer than they were in 1990. AS time goes on that one is forgotten about since it doesn’t show up in daily record’s
        Jan 2007 also had a major freeze as well.

        • AlTahoe

          I found the 1998 freeze article. Also confirms the snowfall that I mentioned below in Morgan Hill that year.
          Here’s the entire article about 1998
          http://www.sfmuseum.net/hist10/98wx.html

          “A COLD SNAP
          DURING LATE DECEMBER WENT A LONG WAY TOWARD VERIFYING THE COOLER THAN NORMAL
          LA NINA TEMPERATURE PREDICTIONS. AN ARCTIC AIRMASS PLUNGED SOUTH OUT OF
          WESTERN CANADA ON SUNDAY…DECEMBER 20TH AND BROUGHT WINTERY WEATHER
          TO NORTHERN AND CENTRAL CALIFORNIA. FOR THE FIRST TIME SINCE THE WINTER
          OF 1976…SNOW WAS OBSERVED IN SAN FRANCISCO AND AS FAR SOUTH AS THE
          MONTEREY PENINSULA. AFTER THE FRONTAL PASSAGE…THE REGION EXPERIENCED
          A WIDESPREAD HARD FREEZE WITH TEMPERATURES FALLING BELOW FREEZING ON FOUR
          CONSECUTIVE NIGHTS STARTING ON THE 21ST. ONLY A FEW RECORD LOWS WERE SET
          DURING THIS COLD SPELL…PRIMARILY BECAUSE IT HAPPENED TO FALL DURING
          THE SAME PERIOD AS THE BIG FREEZE OF DECEMBER 1990.”

        • CHeden
          • AntiochWx

            Inside slider, expecting quite a few of those this year.

          • Thunderstorm

            I remember that very well. Also came with an steady east wind to really get some wind chill. High one day where I live was only 35 and the low 21. Was a big cause of the Oakland hills inferno.

      • Charlie B

        I also have been wondering about Atlantic basin hurricanes. People have commented about the active year we have (are) experiencing, and then drawing conclusions from it. In my mind, that is dangerous, because then one asks why the US wasn’t hit by a single “major” hurricane for well over a decade, and draws certain conclusions from that. Why is it that the most recent Category 5 storm to hit the continental US remains Andrew in 1992, and before that it was Camille in 1969 and before that it was the 1935 Labor Day storm. Plus, what about the storms that hit what is now the US in the 1500’s or 1600’s? Here is a link to a Wikipedia article on hurricanes in the 1700’s. Looks like lots of storms. How many storms were missed because there is no record of them? (It notes that the first accurately recorded tropical system was in 1743.)https://en.wikipedia.org/wiki/List_of_Atlantic_hurricanes_in_the_18th_century

    • Pfirman

      You said it yourself….either a grain or the whole shaker.

    • jstrahl

      One editing note, you may wish to change the year on “NOVEMBER 20, 2017.” 🙂 Thanks a LOT for this.

      • Charlie B

        QC was lacking, obviously. (Change made).

    • It’s impossible to initialize data to forecast precipitation weeks and months in advance. CFS does it 4 times a day. Best to just look at height anomaly trends for one particular run for a week and save a little salt. Also heights forecast for even a month can’t take into the possibility of a honker wet week and then three weeks of 75 degrees under a huge ridge. The month might look shitty height wise and the precip forecasts follow heights almost in lockstep yet for the month described above precip may be 150% of average

    • Chris

      ……. and I think your forecast will be right!!!!

    • jstrahl

      Not my forecast, but interesting counterpoint to numerous assertions made here that drought and RRR are a new normal, an old study, all of …three months old. 🙂

      https://phys.org/news/2017-07-california-wetter-century.html

      http://www.sandiegouniontribune.com/news/environment/sd-me-california-wet-20170707-story.html

      • Pfirman

        I like this. The south will suffer but will still get its water from upstate, just like now.

        • jstrahl

          Down 3% is not really “suffer.” LA gets around 15 inches a water year, 35 is .45 inches. 🙂

          • Pfirman

            You read all the posts from there. Even the cacti complain.

          • jstrahl

            Thanks, i forgot about that. 🙂

      • AntiochWx

        I have no issue with the study, it has some sound physics. I just lean more to the long term trend decreasing due to the long term trend of the Hadley cell expansion. AGW does more than just melting the polar ice caps. It also weakens the Polar cell. The polar cell when weaker (especially during the transition months Oct-Nov), (Feb-Mar) won’t expand as far south, so the Hadley cell expanse filling the void. Well this expansion pushes the jet stream further to the north, which is already happening (the mean latitude position is further north), which causes longer periods of drier weather. Certainly during the wavy meandering periods you could get stagnant trough patterns to make up for the decreased precipitation, but the jury is still out on that one.

        • jstrahl

          So i gather you think the climate scientists who authored the study did not account for the effects of AGW on the polar cell?

          • AntiochWx

            I think they are underestimating it. You melt out the sea ice in the summer, and it’s going to have a much larger effect than most think (the sea ice is polar cell food). I side with Dr. Jennifer Francis on this one.

          • jstrahl

            Doesn’t sound , judging from the article, that they just made estimates, they used 38 climate models. I don’t know for sure, but doubt that they don’t realize the effects of melting sea ice.

      • jstrahl

        Interesting stuff, via the first link.

        “They also found the winter months of December, January and February, when California traditionally gets the bulk of its precipitation, would account for much of the overall increase in precipitation. During those three months, precipitation levels would increase 31.6 percent in northern California, 39.2 percent in central California and 10.6 percent in southern California.

        All these percentages are in comparison to data from the Global Precipitation Climatology Project observed between 1979 and 1999.

        “Most previous research emphasized uncertainty with regards to future precipitation levels in California, but the overall thought was California would become drier with continued climate change,” said Robert Allen, an associate professor at UC Riverside and one of the authors of the paper. “We found the opposite, which is quite surprising.”

        The past uncertainty as to whether California would get more precipitation in the future was due to several factors, including year-to-year variations in individual weather events, shortcomings in models and because California lies within a transition zone, where northern parts of the state are expected to become wetter and southern portions are expected to be drier.

        Allen, a faculty member in the Department of Earth Sciences, and Rainer Luptowitz, a graduate student working with Allen, analyzed 38 climate models developed around the world to reach their conclusions.

        They found that warming in the tropical eastern Pacific Ocean sea surface temperatures, an area about 2,500 miles east of the international date line, is the main reason for the predicted increase in precipitation levels.

        The warming sea surface temperatures encourage a southeastward shift of the jet stream, which helps steer more rain-producing mid-latitude cyclones toward California.”

        Read more at: https://phys.org/news/2017-07-california-wetter-century.html#jCp

  • Craig Matthews

    Along the lines of the Feb 2.1922 rare low elevation snow event, I made a succession of 500mb height anomalies of the week leading up to the Feb 2 event. I numbered the maps from #1 to #4 due to the fact that disqus tends to screw up the order. Anyway, I did this so we could see where that anomalous cold Low/trough originated, and evolved, and how the NHem anomalous pattern looked in general during that time…here goes…. https://uploads.disquscdn.com/images/de5f01e727d386788e401b9f162ecabcaf5719fd5ed3311512fecec8f76c207c.gif https://uploads.disquscdn.com/images/1a83f026420724f6a89b579b29478a231a82bb5a6c38bad6079336e267c5846b.gif https://uploads.disquscdn.com/images/b1fb6ce0d025382695acf61206effef05e2055b0e42760d9cd019259d6e77340.gif https://uploads.disquscdn.com/images/13e4f5cc49d047269a7da811096e519f08c4b6b38affe4352ff8f92e0d402d86.gif

    • Pfirman

      Almost 100 years ago. What a different world now. My mother had her first birthday the preceding December.

      • Craig Matthews

        Oh how much things have changed since then. My grandpa use to talk of the days of playing in the snow as a kid in Priest Valley, which is a Valley located between King City and Coalinga. He would say it would snow on a yearly basis in the late teens and 1920s. My dad remembers snow many times during every winter in the 1940’s and ’50s in Clear Lake when he was a kid. That rarely happens now.

        • Pfirman

          Indeed. I remember that One Mile, aka Sycamore Pool, in Bidwell Park froze and people were ice skating on it. 1972,

    • Jason Jackson Willamette

      That’s amazing you could gather those images from so long ago. What an incredible cold pool of air coming down to this latitude. Great job!

      • Craig Matthews

        During these type of regimes and events, its all about the position, strength, and shape of the anomalous Ridging in the Aleutian area that dictates where that cold pool from the north ends up sliding south, or even southwest down over the western US.

    • Thanks Craig your maps gets me lathered to do a bunch of comparison to other years. Of interest or curiosity is the SST’s in the DJFM 1921-22 year look very close to 2001-2002 in the NP and ENSO area yet precip is markedly different for the season. I then checked SOI and somewhat similar SOI pattern. My next leap would have been for MJO but LOL that was only ‘discovered’ in 1976 or so. Central Coast and SoCal did remarkably well for a neutral ENSO year. Norcal and PacNW didn’t do well at all.

      • Craig Matthews

        Very interesting will like to check that out. I’m in the process of doing some other “cold snap” winters at this time. The similarity of the position and shape of the Aleutian Ridge during every cold snap here in my findings so far is astonishing.

      • Dan the Weatherman

        It seems to me that 2001-02 was a zonal flow fest, while it looks as if 1921-22 was much more highly amplified.

    • Dan the Weatherman

      Ridge north of Hawaii and south of the Aleutians with a broad trough over the West Coast equals good storm opportunities for CA and this pattern from 1922 is a prime example of that. It does look as if it were quite an amplified weather pattern, especially on Frames 2 & 3.

      • Craig Matthews

        Especially when the Aleutian Ridge is undercut by a sub tropical jet that phases with the northern stream cold systems off the Ca coast…kinda like this last winter, and other winters like 1992-93.

    • Boiio

      This is great. Thanks for posting!

  • Thirstier Nick (Santa Maria)

    It’s not fall without the gust of those NE winds. First ones of the season right now. Not good for my allergies.

  • Question yesterday regarding weather links for education and explanations.
    Daniel has an excellent link page to many topics we discuss.
    http://weatherwest.com/links

    This link is about as good as it gets for education.
    http://www.theweatherprediction.com/
    “Google search” can be used specifically for the site, too. Be sure to tick the bubble because it doesn’t default to site search.

  • honzik

    I like this – it seems like a shift in the forecast. Has there been a projected weakening of the HP ridge over California? What saith the ECMWF?

    http://www.twisterdata.com/data/models/gfs/3/maps/2017/10/04/12/GFS_3_2017100412_F264_PCPIN_24_HR.png

  • AlTahoe

    The biggest snow I remember seeing in the Bay area mountains was Feb 2001. Almost 3′ of snow above the 3k level.

    https://mthamilton.ucolick.org/public/pictures/snowpics/

    • Dogwood

      Great link thanks for posting that.
      As a lifelong resident of San Jose I can attest to rising snow levels and at less frequency than the 70’s thru the 90’s. It used to not be unusual to see the entire prominence of Hamilton snow covered for 4-5 days.
      Mt Umhunum had its own micro climate on the north face that showed a lightning bolt shaped snow slope for a week some winters.
      Ah the days.

      • It seemed like almost every spring and a few time in the winter. I grew up in SJ too.

  • Jason Jackson Willamette

    OT, but I thought I’d share. On 60 Minutes, this past Sunday night, there was a segment on the Hubble Space Telescope that was fascinating. It’s been up there, looking out into space for over 25 years. Amazing. A number of mods and tune ups have occurred over the years to keep it operational and improve its optics and electronics. The images coming in now since the latest upgrades have opened up the Universe to allow Hubble to peer back nearly, to the beginning of time, the big bang. It’s replacement will be launched soon. That telescope will be able to see, according to the astrophysicists, THE big bang original moment…

    Here is the page link to Hubble images, and a downloaded image to share below.

    http://hubblesite.org/image/4024/gallery

    https://uploads.disquscdn.com/images/12ae2f5404bf83827d738b059a889fc4432349fb7b68b0c95b3f9a102065e10e.png

    • Bombillo1

      That will be interesting. Like a trail camera, we’ll probably see Dennis The Menace with a lit match.

    • Jason Jackson Willamette

      Edit – that image is from the “Near Field” image set that looked out into a segment of the night sky above the big dipper. To the earth located telescopes it appears to be devoid of stars. But Hubble, pointed at that location for many hours to allow the faint photons of distant light to collect on the grid, revealed in this image, GALAXIES, not stars. We cannot comprehend the vast reaches of space, for how can we grasp infinity with our finite minds/intellect? And even more amazing, is that each particle of sand, every snowflake, every leaf, every discernible object, is unique in the universe. What lay behind this infinite capacity to create anew? IMHO, that is our quest, that is the journey we’re on, to find those answers…

      • PRCountyNative

        Infinity goes the other way too – inside. I find I fit nicely in-between the infinity of the small and the infinitely large. And it provides a sense of connection to all – a non-uniqueness – a continuum in which we belong. We all inter-are, and can just be. No action required. And California Weather helps keeps things swirling (notice weather reference to stay on topic).

        • Gravity is always on topic 🙂

        • Jason Jackson Willamette

          Precisely. Speaking of the Weather…. Ummmm, whew, well, yeah, nothin’. Gonna go wash the dishes, my turn.

      • molbiol

        Pondering things like that can be scary for me sometimes. Keep in mind that we don’t even know what we are made of: organ systems, organs, tissues, cells, macromolecules, molecules, atoms, hadrons (protons/electrons/neutrons), quarks, leptons, bosons, dark matter, strings..????
        And we (outside of religious beliefs) have no idea what the point of all this is…

        • Jason Jackson Willamette

          When I ponder these “things”, I get chills, because I can sense the connectedness of it all. And yes, we’re made up of the elements birthed from the furnace of the stars, the “star dust” from which we all came. But,,, a bucket of minerals and dust does not define who we are. Those elements are just the materials that build the house of our present existence. Where does the animating “life force” emanate from?

          When we step away from the mortal coil at the end of this journey, we return to the light, and contained in that light is the song of creation. Hear it, and we’re blissfully home.

          • molbiol

            What follows after death is the great mystery and one that I shudder to ponder. I’ll just leave it at that since we don’t want to dovetail into any philosophical or religious debates…

          • Jason Jackson Willamette

            Please, only sharing and hoping to find kindred souls whose eyes and hearts are open.

      • Infinity is before the big bang.

      • CHeden

        I am not aware of a “near field” Hubble image. Are you referring to the Deep Field image, which took 10 days and 362 images to capture? There is also a Ultra Deep-Field Full range image, which is compilation of images at various wavelengths.
        Either way, remarkable.
        Lastly, that we measured/confirmed gravity waves is perhaps even more astounding, IMHO.

        • Jason Jackson Willamette

          You are so correct Professor Heden. Will this affect my grade? : ^ {

    • MetaGhost (Berkeley)

      “That telescope will be able to see, according to the astrophysicists, THE big bang original moment…”

      Wait…didn’t that already happen?

      • malnino

        Think “speed of light” .. you don’t see things the moment they happen. Even the sun dips below the horizon 8-9 minutes before you see that effect, I believe.

        • MetaGhost (Berkeley)

          I was joking.

          • Pfirman

            Jokes about light take their time it seems.

        • Pfirman

          Wow, this explains why I am always late.

          • Tuolumne

            Me too, and I’m late in responding, again.

          • Pfirman

            Still pretty spiffy.

          • Tuolumne

            Thanks.

            That’s because I’m inspired by Spaceman Spiff, my favorite-ever comics page character.

      • CHeden

        There was no light associated with the Big Bang until 240,000-300,000 years afterwards.
        https://phys.org/news/2016-11-universe.html

        • Pfirman

          Pretty sure that was because of the first universal weekend. Gloria in Excelcius Dei.

          • Jason Jackson Willamette

            You’re funny! LOL

  • Fairweathercactus

    Not just one heatwave this weekend looks like another one is coming more likely next week for So Cal.

    • AntiochWx

      Buckle up, the blocking means business so far.

  • molbiol

    Two more ‘low snow event images’ and then I’ll shut up. The first is from the Jan 10 1949 event and the second is from Jan 10 1950. The 1949 event affected California, while the 1950 event impacted the Pacific Northwest. Portland, Eugene, Seattle all received record setting snowfall. Seattle picked up an incredible 60+ inches of snow for the month. Eugene picked up 36 inches of snow. Note the orientation of the Aleutian block. During the 1950 event, the block was well offshore (toward the Bering sea) with a rex CoL underneath. There was also very cold air over British Columbia with lots of Baroclinicity over the PacNW. As a result, California missed out on all the snow as this pattern typically causes subtropical ridging to push in from the Southwest. The 1949 event is the more classic setup that CHeden etc. discussed below. One final word of caution, these patterns do not bode well for the rest of the winter, since they are typically followed by weeks of relentless ridging and dry weather. Examining the weather patterns that follow these events would probably yield some interesting results but I am too lazy right now…

    https://uploads.disquscdn.com/images/ccb0b9bc7298199b15f72f6cb01600dfad7f8138393e43c7fba76faada4cc058.jpg

    https://uploads.disquscdn.com/images/fd88297f52f3ede68febfff2b3223461f6c1e3ae18337bbdb2ea34c7b167346a.jpg

    • Craig Matthews

      Late 1940’s through mid 1950s featured some very cold outbreaks across western U.S. 1948-49 thru 1950-51 winters in particular were quite cold in Ca. Havent checked the data yet but I think the 1948-49 winter may be considered one of the coldest winters on record in this state…could be wrong and i’ll have to re-check on that. BTW, agree with you irt these patterns being followed by weeks of dry wx and ridging.

      • Pfirman

        I can tell you they were quite cold in Cincinnati also. I was in third grade and the snow kept me happily out of school.

    • Good point with meridonal dominant patterns vs zonal dominant patterns. One or the other tends to dominate and we just don’t get the long end of each one of those sticks for one winter. I guess one obvious exception would be 1861-62. A pretty good sized volcano erupted on Halmahera around that time, IMO, possibly altering the atmosphere for the winter season. Strong emphasis on ‘possibly’.

  • Craig Matthews

    Following up on earlier comments regarding the 1922 low elevation snow event, and 2Pluvious comment regarding ssta, here’s what the ssta spatial pattern looked like in the fall of 1921…I see some similarities to the evolving ssta spatial pattern potential here.. https://uploads.disquscdn.com/images/d1789bd0ee0148657aba785033161347ad3a32477db43642be725524906e8975.png

  • Nate
    • Darin

      My eyes first that low as 963 and I thought WHOA…still that is quite the setup out in 162land.

      • Pfirman

        Aka la la?

    • AntiochWx

      Looks like the Euro wants to retrograte the new developing low, the blocking is strong again this run.

      • Rose

        What does that mean in layman terms, particularly So Cal?

        • AntiochWx

          Dry. High pressure still dominating, as of now.

    • CHeden

      The low should be retrograding….ie. away from the coast.
      A Rex Block well off the coast should result if my suspicions are right.

  • Thunderstorm

    Surprised no one has mentioned the next tropical storm Nate which will evolve over the gulf this weekend. So says the -talking the tropics – blog site today. Should turn hard north with landfall between Lousiana and big bend area of Florida.

    • Nate

      Nate…great :/

    • Who Killed Kenny Strawn?

      The way this season is going, expect it to rapidly intensify to a major upon landfall.

  • This is a cool comparison of MPAS core vs NCEP-GFS (not new VF3 core) it’s initialized once a day at 00Z. This comparison is for 240hr from Tuesday 5PM PDT.

    GFS is black contour, MPAS are pink, Height difference shaded in dam and vector wind difference in m/s. I’m challenged reading this but yellow to darker shades is where MPAS forecasts higher pressure than GFS and going the other way to green MPAS height is lower than GFS forecast. These stay kinda lock-step for first 96hrs or so.

    Please note this does NOT show troughs and ridges just pressure differences, wind direction and speed in meters per second between models. Easy example is off of Baja. The low that GFS has been playing with doesn’t show up on MPAS. MPAS is not putting a ridge down there just showing the difference in height shaded yellow and difference is wind speed and direction.

    https://uploads.disquscdn.com/images/a1b482fb21eba8aa658c9e2a67c3bea07c28d5ae243217e552ad2393c62451b3.png

    • Pfirman

      With all due respect, I would like a doormat that looks like this.

      • annette johnson

        It would add a lovely splash of color to an entryway…

        • Jason Jackson Willamette

          I don’t know. Looks like a bunch of ants running around on it. First time guests would look down and start stomping the mat, or maybe screaming. And there you are, laughing from the other side, ha ha, ha ha, guess who’s here!

          • AntiochWx

            but if they don’t know what it is, do you really want them as guests? I kid I kid.

          • Jason Jackson Willamette

            I’d be more afraid is they DID know what it represents…

            Ekkkk, it’s a weather nerd : ^ ~

          • AntiochWx

            haha true true. Me, “hey did you bring the wine” , Guest, “No but I do know how to hack in and reprogram the Euro runs, want to watch the weather west crew squirm?”
            Me, “you are so evil!!, come on in”

          • annette johnson

            Lol. You might be on to something. The doormat to use when you DON’T want someone to come to your door! Reminds me, I found a dead tarantula by my door the other day. Probably the result of me spraying for other unwanted critters. Poor guy, I didn’t intend to target him.

  • jstrahl

    18Z GFS does bring considerable precipitation to the Oregon/Washington coast by 384hrs, jutting into Del Norte County, with some precipitation making it all the way to looks like northern Sonoma. Also some light stuff north of Tahoe.

  • Great Winter of 2017 (SMC)

    Forecast for future Nate can only seem to go down from here, I predict CAT 2-3 landfall on Sunday near Alabama, Mississippi coast

    • Who Killed Kenny Strawn?

      I’ll up the ante: I predict a cat 5 landfall somewhere on the Gulf Coast.

      • Great Winter of 2017 (SMC)

        What is you reasoning by this answer, not saying your wrong, but like to hear others input

      • molbiol

        Latest from NHC:

        Environmental conditions look quite favorable for strengthening over
        the next few days, with low shear and very warm and deep water in
        the path of the cyclone. The various rapid intensification indices
        are all higher than the last cycle, suggesting an increasing chance
        of rapid intensification occurring. The fly in the ointment,
        however, is all of the potential land interaction, first over
        Central America and then possibly over the Yucatan Peninsula. As
        a compromise, the intensity forecast is raised considerably from the
        previous one during the first 3 days, but is still below some
        guidance…

        • Jason Jackson Willamette

          Likely will be a cat. 2, which is pretty bad. The killer is all of the rain, as Harvey showed.

    • Jason Jackson Willamette
  • happ [Los Angeles]
    • jstrahl

      Monterey Bay a sharp dividing line?

      • happ [Los Angeles]

        I am confused by the warming of what was going to be a La Nina. The LA Nina was 2010/11 was cold.

    • CHeden

      Ridging over the west and eastern thirds of the country, with troughing over the central sections. Looks like a broad-brushed cookie-cutter La Nina forecast to me.

      • Patrick from Stockton

        Yeah, KCRA-TV Meteorologist Dirk Virdorn showed a similar graphic a little over a week ago talking about a upcoming LaNina setup. Usually they stay away from long range speculating…FWIW…

        • Pfirman

          They feel constrained to say something, especially if they are on tv.

      • Pfirman

        “…broad-brushed cookie-cutter….’ You talkin’ about my wife? Huh? Huh?

        • CHeden

          She’s a baker?

    • I’m barely on the rainy side. Lol

      • Cap’n

        The outlook is fine tuned to block by block accuracy. You might get 102.3 % of your annual average while the guy across the street might be in the orange and suffer with a dismally brown front yard.

        • What about the Barney Bowl?

          • Cap’n

            I’m curious about that thin line of white jutting through Wyoming and Montana with no “label”. Is it just no-man’s land? Or the landing pad for the coin toss?

          • tomocean

            They figured not enough people lived in those areas to bother with a forecast.

          • Pfirman

            Buncha yellowstone bellied liver-spleened forecasters if they did that.

          • AntiochWx

            That is the great line of confusion, anybody under it will suddenly become confused.

          • Thor

            passes right over…or thru me…apparently I am neither here nor there…wet nor dry…or maybe its the goldilocks line??

        • jstrahl

          Still time to move to the right side of the street.

          • Pfirman

            Or at least the other side.

          • GR

            Grab your coat, and grab your hat,
            Leave your worries on the doorstep.
            Just direct your feet
            To the rainy side of the street . . .

      • Thunderstorm

        Looks exactly the same as last year from accu-weather.

    • Thirstier Nick (Santa Maria)

      Are they just rehashing the winters of 2013-16? Let’s see…I predict more of mildly wet.

  • happ [Los Angeles]

    California’s reservoirs are full, but will this winter be wet or dry?
    http://www.mercurynews.com/2017/10/03/will-this-winter-in-california-be-wet-or-dry/

  • AntiochWx

    If anybody is interested in learning about the QBO, here is a good article.

    http://journals.ametsoc.org/doi/full/10.1175/JAS-D-13-096.1

    • QBO fascinating yet it gives me a headache. I’ll look at this tomorrow. Thanks for the post

      • AntiochWx

        Don’t worry, it gives me a headache too. Alot of the material is hard to digest, but it is some higher material for those looking at more of the advanced meteorology.

  • AntiochWx

    When exactly is the Tule fog first noticeable?

  • Flyin_Pig

    I’ve been fascinated with the recent posts about historic low elevation snowfalls. About 20 years ago, shortly after I moved to this area, there wasn’t an article in the Oakdale Leader about historic snow storms in the area. If memory serves me, it listed 10 times between 1880 and 1980 when an inch or more of snow fell. So I figured about once every decade was the average.

    The last time was 1976 so has now been over 40 years!

    We have had snow flurries every couple years and some accumulation a few times but nowhere near an inch in the 25 or so years I’ve lived around here.

    Is this because the earlier years were anomalously cool, or do you think a gradual slight increase in temperatures over the years has turned this from an “unusual” event to a truly rare one?

    I’m about 10 miles east of Oakdale and 25 miles west of Sonora. Elevation in the area is under 500 feet.

    • Pfirman

      You know what they say about pigs going to heaven. Just do the math.

      • AntiochWx
        • Pfirman

          Speaking of cards and stacks. What is that image from? I feel I should know it.

          • AntiochWx

            We don’t need no education 🙂

          • Pfirman

            Love the song but never owned the album. Only heard it on the radio back when.

          • AntiochWx

            Big Floyd fan, the flying pig is from the album Animals.

          • Tuolumne

            That was a different album, with a rather chilly and remote demeanor. Suitable for a discussion of low-snow events.

          • AntiochWx

            I know, but was giving a hint 🙂

          • AntiochWx

            Alot of their songs are suitable for what we discuss here! Like comfortably numb.

          • We’re in denial that we are sick though?

          • AntiochWx

            Yeah, I definitely have some brain damage

          • Tuolumne

            Got to keep the loonies on the path…

          • Cap’n

            There’s someone in my head but it’s not me.

          • Tuolumne

            The cover of Pink Floyd’s “Animals”.

          • But he ‘feels’ he should know it so The Wall works for another song

          • Pfirman

            Heh, you are such a brick.

          • A lot of scotch. “Now I’ve got that feeling once again
            I can’t explain you would not understand”

          • Pfirman

            That was a ‘b’ not a ‘p’.

          • Oh f. I’m snotting I’m laughing so hard. Good chuckle but a waste of some 12 y/o single malt

          • Pfirman

            So sorry. Cheden wants to know where you live.

          • I pity anyone trying to get some useful Wx info from their mobile device tonight

          • Pfirman

            Sure, but we’re all up on useful addresses.

          • Go backwards. A whole new universe opens up.

          • CHeden

            Be there in 4 hrs if the brand is right.

          • DayHoe Herald

            Thank goodness we’re comfortably…….numb

          • AntiochWx
          • Tuolumne

            Bears watching.

          • AntiochWx

            It’s on the prowl for low level snow.

          • MetaGhost (Berkeley)

            Sheep:

            What do you get for pretending the danger’s not real.

            Meek and obedient you follow the leader

            Down well trodden corridors into the valley of steel.

            What a surprise!

            A look of terminal shock in your eyes.

            Now things are really what they seem.

            No, this is no bad dream.

    • AntiochWx

      No doubt the climate state is different today. It can still happen, but the cards have been stacked.

    • Tuolumne

      I’ve noticed that snow events in the higher hills of the Bay Area have been a lot less frequent than they were back in the late 70s. These used to happen regularly in the December-February period.

      I still remember the snowfall in the Mt. Hamilton Range on April 10, 1974, which got down to 3500 feet or lower. There was another April snowfall in the Santa Cruz Mtns. on April 1, 1982. After work (I got off at 3:30) I drove up to Skyline Road and toured through a winter wonderland, in April, in the Bay Area.

      • Tuolumne

        Then I read down the comments and find others have noticed the same reduction in Bay Area snow during the same period.

        • It was a spring ritual in HS to cut a few classes, load a P/U with snow and drive it back to school

          • AlTahoe

            Up at Henry Coe? We did that a few times in high school.

          • Mt Hamilton. I was in San Jose at that time

    • rob b-Truckee/East Bay

      I think it also is part of the growth of the area, more concrete and buildings to hold the heat in. If you look at parts of the Bay Area that we’re not developed 50 years ago like they are now you see much lower lows. San Jose often sticks out, the orchards that old time Valley residents talk about are long gone taken their place are large campuses. Hard for the temps to get that low with the development.

      • AntiochWx

        But then how does that explain the decrease in snowfall trend on places with not much urban heat. Like Mt Diablo etc?

        • Tule fog is a topic we address annually. Urbanization in the valley may have something to do with less tule fog. I still think that if you get some early precip to get the soil wet It becomes a fog factory

          • AntiochWx

            I’m not sure what the affects of urbanization does to the Tule fog, I would like to see some studies on it. I have read articles about how they think AGW does play some role in it, but would love to hear more about it.

          • Pfirman

            Hear this. Drove up the valley in say winter of 1961 or so and the fog was like soup and the cold was enough to form icicles on the hood ornament.

            Think that could happen now on a regular basis like then?

          • There were huge debates. Probably two climatological eons ago. Life was simple. Probably early 2014.

          • FolsomPrisonBlues

            I have heard so much about tule fog in the valley. I have been here a few years and have yet to see any 🙁

          • MetaGhost (Berkeley)

            i grew up just east of Sacramento. The fog was epic. Sometimes, 20′ visibility. I remember a pile up on the Yolo Causeway that was literally hundreds of cars.

          • Pfirman

            If you need to drive in the winter, count yourself lucky. That was and could be still some scary conditions.

      • Flyin_Pig

        A good point but the area around me is still quite rural. Mostly open rangeland with scattered orchard plantings. Closest town only has population of 100. About 10 miles away is a small city of about 20k pop.

      • V-Ville

        I grew up in the Berryessa area of San Jose surrounded by orchards. Moved there in the late 50’s and vividly remember the big snowfall we had in the early 60’s when I was a kid. I still remind my brother that he promised to help build a snowman then ditched me to hang with his friends.

  • Nate

    This low snowfall talk is really interesting! Decided to take a look at Mt. Hamilton’s (4,200′) snowfall data, and found this data. I plotted it out, and there is a slight downward trend; however, this data should be taken with a grain of salt. There are multiple gaps and inconsistencies (don’t think the big 2001 snowfall was included), and I estimated 2017’s total (probably somewhere around 12″) to show how it compares with past years. It’s kinda cool to see though; 81-82 was apparently their biggest year with nearly 50″.
    https://uploads.disquscdn.com/images/acdea38f88d227615e9a4d2bb00ef9964452a0f4008c657fe6586557100b2233.png

    • AntiochWx

      I’m going to go ahead and make a prediction for Mt Hamilton. I think they see between 20-30″ of snow this year.

  • Boiio

    The most impressive low snow event of my lifetime in Marin was in February 2011. I hiked up the the top of Mt. Tam just as the rain was switching over to snow and watched the temp drop to 30F. By the next morning almost 8″ of snow had accumulated and people were cross-country skiing! I took these photos up at the top of Mount Tam, which is 2500ft and less than 10 miles from San Francisco. https://uploads.disquscdn.com/images/67496ceda4a4c6b0ecd571a431001edf82cf060a78f54feca97254e8d37ce9d7.jpg
    https://uploads.disquscdn.com/images/ddc4b9f69434e0f6476a198adcb73be9fe366f9ef271e07e173c93267abcf8a2.jpg https://uploads.disquscdn.com/images/d9b412346339d571b631a7f1ae16dc9f003b3a5754c6030346a6048e30a1bca0.jpg

    • Nate

      Wow, that’s awesome. February 2011 was great; that’s the only time I’ve seen snow at my location (400′) in the South Bay. On the 26th, there were slight accumulations down to 350′. It wasn’t much, but places 700’+ got about an inch (that subsequently melted by mid-morning).

    • Chris

      Here is a pic of the biggest surprise in Feb 2011.
      They had forecasted snow to sea level the night of the 23rd but never happened.
      Then, training convection developed over the east bay hills south of Mt Hamilton and spread SW toward south Morgan Hill to Gilroy with especially heavy snow where this pic was taken in San Martin!!!
      This was taken at 3:30pm on Feb 24 https://uploads.disquscdn.com/images/6c9e0158e8f6f1378689045cd1e81a0af682a889942521f0ca5e087bec3ae564.jpg

      • Craig Matthews

        That same training convection brought up to an inch of snow in Prundale of all places. Parts of Salinas also experienced accumulating snow that late afternoon of the 24th. The snow fell mostly in the form of graupel, but there were actual snow flakes mixed in. I was working in Carmel and watched that line of cells come in from the nne. Unfortunately that line of cells dissipated once it reached the big sur coast due to the sun setting too soon 🙁

  • Phil(ontario)

    December 29 2014 brought 1-3 in of snow to Temecula in riverside county at 1,017 feet. Snow lasted in the shade for about 2 days.
    What happened after was about 0.00 rain and close to the hottest January on record.

    • molbiol

      I remember that storm screwed us over here in Lancaster. It didn’t retrograde far enough to the west to pick up sufficient moisture. As a result, we got nothing but wind from that storm. Had it picked up more moisture, then a more widespread low snow event would’ve occurred.

      • Dan the Weatherman

        It seems that when we get an anomalously cold storm like this that brings snow to areas that don’t see snow all that often leads to a prolonged dry spell afterward. The dry period that followed lasted for nearly 2 weeks here in Orange (actually shorter than I thought until I checked my weather records). I had thought that January 2015 was rainless here in Orange, but my records showed that I had 1.13″ that month. However, January 2014 was completely rainless here.

        • Meridonal flow was on steroids during that time of RRR. I believe it was also rainless up as north as SFO. If not rainless it was very very little.

    • Hollow Scene (Riverside)

      That was a really odd storm during the reign of the RRR. I hope we get a cold wet storm like Dec 2008, not that one!

    • redlands

      Yes i remember that storm — if i remember correctly upper Redlands got a real slight dusting at 2000ft — where i live at 1500ft didnt anything — it came real close

  • Thunderstorm

    Definition of mass insanity. They were actually going to debate a bill for allowing concealed weapons with silencers in the Senate.

    • The NRA operates like a mafia, go against them and your days are numbered if you are red. NRA needs to go away. Now, back to the weather, 00z run came in just like the last one, bone dry. https://uploads.disquscdn.com/images/2ac0718277b9780a2ef7ae951fdf76107ce324163b30593ae0cbea38c5d0c1c8.png

      • JGold

        What do you suggest happens to the NRA? Ban them? Don’t let them contribute to candidates?

    • Chris

      I think this discussion should be under a different page.
      Let’s keep this weather related ?

    • 805 Weather (Camarillo)

      Please. You know better…

    • Hollow Scene (Riverside)

      I’m, literally, using one hand to pull the other away from the keyboard… can’t…. stop….Ooh look pretty clouds out!

  • Cap’n

    23F this morning in Truckee; a lot of chilly road workers standing around on 89.

    • AlTahoe

      Same with 28. Thank god construction season ends shorty. I have been enduring 1 way controlled traffic for the entire summer on 28. My 35 minute commute has been taking 1 hour and 15 minutes each way.

  • AlTahoe

    GFS keeps hinting at a cold bowling ball to come down the Oregon coast by the end of next week. Something to keep an eye on for future runs.

    • AntiochWx

      It’s a dry cold low. Starting the theme I think will be the main storyline of this winter. Just hope some moisture gets thrown in at some point.

  • Charlie B

    Returning to weather related topics, I am interested in what is happening up in Alaska and in particular, Barrow. I think it is important to understand what is really going on up there since the GOA (far south of Barrow obviously) is the breeding ground for many of our storms, and I also remember that the nasty cold snap in 1990 started up in the interior of Alaska with record lows. So, I think that what is happening up there is highly relevant to what is happening here. In that vein, I have noted that Barrow is consistently running far above normal in actual temperatures, and the forecast models show a tendency for far above normal temperatures in the long range. So digging around a little I came upon an Alaska weather blog “Deep Cold.” It bills itself as an Alaskan weather and climate blog. “All science, no politics.” It is very interesting, even though I have only looked at a few posts. One that caught my eye dealt with the “warm” Barrow temperatures. According to the post, Arctic Ocean sea ice is 500 miles(!) off shore from Barrow currently, which means that north winds are bringing relatively warm modified air into the area. Makes sense. There was also a depiction of the difference in ice coverage between 1983 and 2017, which showed ice hugging the shore in 1983 but now, as noted, the ice is far away. (One comment did note that other areas actually have more ice now than 1983…). Anyway, it looks like a good read for those interested in these things, and the interconnection between what is happening up north as it related to down here.http://ak-wx.blogspot.com/

    • Honestly I think what happens here affects there.

      • Craig Matthews

        Don’t the tropics,ie tropical convection/waves and oscillations affect the arctic more then here? ;-).

  • Craig Matthews

    A small interlude to the wintertime snowfall discussions…Been following this guy “Tom” for a few years now. His summer forecast this year came almost spot on. Tom is a “big picture” kind of guy, kind of like Phil Wiegand, who is another one of my top favorite mets I’ve been following on twitter for a coupla years now. Take a look at Tom’s discussion, then his analysis of how he did as far as his forecast for this summer, for those that are interested. Very educational reading, and I humbly admit there is a lot of stuff he talks about that is over my head, lol. http://www.lightinthestorm.com

    • Quagmire Cliffington

      He also started myspace.

  • thlnk3r

    I question this forecast for 2017-2018 ………

    2017-2018
    https://uploads.disquscdn.com/images/5e7d4c3def276b621e67152aabab5b4b6a4538371fdbcf287a9b933234f7f776.jpg

    2016-2017
    https://uploads.disquscdn.com/images/835e1f710bbb2e1a55bb0a093283559dc14d12d23e73a5c3e3f6c28199fd2217.jpg

    Source: https://www.accuweather.com/en/weather-news/2017-2018-us-winter-forecast/70002894

    “In the Southwest, drier and warmer weather will dominate.

    According to Pastelok, warmth will bookend the winter with temperatures capable of reaching into the 90s by early 2018.”

    • Dogwood

      Someone linked that accuweather site yesterday and after I read the whole thing it seemed like a Farmers Almanac forecast.
      A bit too heavy on vague generalities.

  • Eben

    With all the talk about low elevation snowfall, Here are some pictures. I used to take my daughter up to the Saratoga Gap (CA-9 & CA-35, 2650′) whenever I heard about snow up there, so she could build a snowman. There was a consistent string of snowfall up there at least once or twice a winter, but I don’t recall one since the recent drought. Of course my daughter is now 15 and no longer wants to make snowmen!

    March 2006: http://plunk.org/eben/Albums/talia/SnowDay2006
    February 2007: http://plunk.org/eben/Albums/talia/SnowDay2007
    January 2008: http://plunk.org/eben/Albums/talia/SnowDay2008
    December 2008: http://plunk.org/eben/Albums/talia/SnowDay2008-December
    December 2009: http://plunk.org/eben/Albums/talia/SnowDay2009

    • 82/83 El Nino baby (San Jose)

      Agreed. The instances of snow on Mt Hamilton has reduced as well. In addition, a few storms a year would blanket the top of the foothills in front of Mt Hamilton. I think climate change is a player, but its more the kinds of systems we have been getting. Fewer cold dynamic systems and more wet ARs.