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

Filed in Uncategorized by on September 9, 2017 2,875 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.

Tags: , , ,

  • happ [Los Angeles]

    Cloud porn
    Peter Tellone posted this photo of Borrego Valley yesterday evening https://uploads.disquscdn.com/images/8d6856e20a1b50c7d18f663e6a59dec431908fe6fdd6a0a6e73975b99edca4d7.jpg

    • RunningSprings6250

      Clouds to the east are like that this morning too – gorgeous sunrise.

    • Jason Jackson Willamette

      Beautiful!

    • Dan the Weatherman

      Is Borrego Valley part of Anza-Borrego, or is that somewhere else entirely?

      • Stevo Pusser

        It’s part of Anza Borrego.

    • alanstorm

      A low of 42° for Willits on Monday.
      Shall we build a fire?

      • malnino

        Don’t you guys have enough of those of the unplanned variety for the time being? ?

      • malnino

        I know my daughter up in Portland says the smoke is still an issue (Monomah not withstanding) .. hope Mother Nature lends you a helping hand soon and snuffs that out, but quick.

    • Is this illustration rudimentary evidence of larger spreads between highs and lows?
      https://uploads.disquscdn.com/images/41a09386a35e50801f3ec32aed50e27a1c69de1af212694525310115a22095d6.jpg

      • RunningSprings6250

        I read that as ‘thighs and legs’

        I’ll excuse myself now, lol!

        • Pfirman

          Probably got tripped up with the ‘larger spreads’. I will also now excuse myself.

    • Dan the Weatherman

      This summer started earlier than normal, so it makes sense that we start cooling off earlier as well. I am ready for the cooler temperatures!

  • Taz & Storm Master

    i see the 546 line all the way down too CA with snow in the mts

    https://www.tropicaltidbits.com/analysis/models/gfs/2017091312/gfs_mslp_pcpn_frzn_swus_23.png

  • Taz & Storm Master
    • Darin

      Does data exist that tracks first snow by location/station/zip/something? Better yet, first X inches as a way to discriminate from outliers…?

      My imagination is a map by epoch day for each year. Then a trend map of over last Y years. “Change in average date of first snow between 1970 and 2016”. (Everything is easier to calculate from *nix time ;). Then the delta of the given year to the regressed beta could show how early/late a given winter for a given location is. Swap out rain for snow and then do the rest of the state. An interactive website where the depth could be adjusted would be really trick! #onecanhope

    • It’s been trending that way for 3 days now, was at 240 hrs now 168, Lucy is looking less and less of a threat….

  • Craig Matthews

    Very active early morning over Carmel Valley, as Tyler was mentioning. The best activity occurred from central part of Carmel Valley to points west off the coast just after 4am, and again just before sunrise. Was very difficult to capture a shot of the lightning, due to the thick marine layer. But sure was fascinating to watch the constant lightning being amplified through the marine layer. I have never seen the marine layer hold firm in the area throughout an elevated thunderstorm event like what we saw this morning here. Usually the turbulence in the atmosphere(updrafts and downdrafts) associated with elevated convection-thunderstorms over the top of the marine layer next to the coast and in coastal valleys mixes the marine inversion layers out, but was not the case at all this morning. Was able to capture an ok shot of lightning here that probably touched the ground not too far from Tyler’s. https://uploads.disquscdn.com/images/2d68080ef2d9bbc2ee0b04d7c3c31633301c46a2ebad6f3737a295dce8e48e53.jpg

    • Pfirman

      Otherwise known as a ‘Hector Shot’.

  • happ [Los Angeles]

    “Apparent climate-mediated loss and fragmentation of core habitat of the American pika in the Northern Sierra Nevada, California, USA” http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0181834

    • Sokafriend

      This is a fascinating and majorly important study.
      Thanks for posting.

    • Yolo Hoe

      Thanks for posting — reminds me that crop yields will be generally down a bit this year due to ‘hottest summer on record’ — if Daniel’s most recent post is correct regarding this sort of summer becoming more ‘normal’ during coming decades, then we will need increased help from biotechnology advances to rapidly create crop varieties that can deal with new stresses associated with insects, pathogens, heat, etc — food security is resurfacing as a real challenge in feeding a rapidly increasing population

      • If you’re referring to tomato harvests it was the nighttime lows that were too high and blossoms did not set. Maybe with other row crops as well? We all, myself included tend to look at daytime temps.

        • Yolo Hoe

          Tomatoes for the reason you note, walnuts and some others — also tough year for insects and pathogens with the heat + moisture

    • I’m not denying that it’s gotten warmer, however a lot has been going on around the Mt Pluto (Lumber and now Skiing) area from human alterations as well as human induced changes on the Truckee River. Some of those words are too big for me. Were the pika in the blue dot area before 1955? I’m not familiar with the area as many contributors are here so maybe I’m way wrong.

      • Bombillo1

        Habitat fragmentation. Population driven as is climate change.

        • Did the article state specifically human driven habitat change or just climate change? I don’t mean to make you do the work but I’m fragged.

          • Bombillo1

            Habitat Fragmentation is an artifact of urban development that leaves small parcels of land that are unable to sustain wildlife. Usually because access to important feeding areas or seasonal migration routes are cut off. I’m sure everyone here understands this but sometimes jargon gets in the way.

          • Tuolumne

            On another scale, habitat fragmentation also means that the pieces that are left, even if they can support some individuals of a given species, can only support a small population (in each piece) that eventually will go extinct due to inbreeding or chance events.

  • matthew

    I can literally just sit around and watch these things grow all afternoon. They are exploding upwards. Going to be a fun afternoon!

    https://uploads.disquscdn.com/images/4493c740bab550f50c17cbe16534c2c0c6e1572916ab48b33f3e89876cb4db61.jpg

    • BRP (Ventura)

      Great pic! That wasn’t taken with a smart phone was it??? Great clarity. Where are you?

      • matthew

        Taken with an old hand-me-down iPhone 5 from my back yard in Truckee.

    • Cap’n
      • AlTahoe

        Bailing Muzik out?

        • Cap’n

          No keys for that cell.

      • Thunderstorm

        Must be some kind of a record for the Tahoe area. Any given day same o same o. Creeks must be flowing again.

  • Idaho Native

    Heavy drizzle now from an incredibly deep, late season marine layer. I’ll take it since we didn’t get much rain from those tstms!

  • Tyler Price (Carmel Valley)

    I can see some clouds building over the mountains and pretty close tinned to my south/ south east.. hopefully it develops into a thunderstorm! Not counting on any more action today, but I can hope for some! Would be nice

  • AlTahoe

    Phil at the weathforums posted his Analogs and thoughts for this winter. I am on board with it. If you have followed him at all, he is very good with the large scale details.

    “Using ENSO and QBO progression alone: 1956/57, 1967/68, 1974/75, 1981/82, 1989/90, 1995/96, 2000/01, 2005/06, 2007/08.
    The only good solar/geomag matches also meeting the above criteria are
    1974/75, 2005/06, and 2007/08. I’m weighting the recent years more
    heavily for several reasons.”

    “So, my preliminary thoughts are +EPO/-PNA winter, with a cool/zonal regime in the PNW and a persistent SE-ridge.

    Watch for more -NAO this winter compared to 2007/08 and last winter,
    thanks to the continued recovery of the BDC and more equatorward WHEM
    Hadley Cell(s). It still might be a “bootleg” style NAO, though, with
    the Hudson Bay ridging/anticyclonic wave breaking nothing more than a
    downstream feedback to the tropically/QBO forced -PNA/+EPO, at least
    through January.

    Long story short: Cool/wet in the West/Northwest US, and warm across the eastern half to two thirds of the US.

    • janky

      I’ll take cool and wet vs 9 ARs.

    • Is it the contributor from Maryland? I’ve gotta run but hope to contribute to this thread later.

      • AlTahoe

        Yep

    • Thunder98 (Santa Maria Valley)
      • Dan the Weatherman

        I am also Dan the Weatherman on TheWeatherForums.

    • SoCalWXwatcher

      Please NOT 2007/08!

      • AlTahoe

        2007/2008 had some of the deepest snow I have ever seen at Lake Level Tahoe right around the Superbowl. January had super cold storms with drifting light fluffy snow. The winter ended early but January and February were amazing up here. I would love to see another winter like that.

        • SoCalWXwatcher

          I guess I’m viewing it from a SoCal-centric perspective. I wasn’t aware it was that good for you guys up there. It was one of the worst ever down here. 3.21 inches of rain. (Normal is 15.14″)

          Seems like the Southern 2/3 of the state saw below normal.

          http://ggweather.com/ca2006rain.htm

          • AlTahoe

            We actually ended up below average precip and snowfall for the winter but the 5 week period in January through early February was crazy.

            http://thestormking.com/tahoe_nuggets/Nugget_132/nugget_132.html

          • Cap’n

            I love these Storm King write ups! I’ve read certain ones multiple times.

          • January 2008 was stellar but the only above average month of the season. San Jose finished with about 80% of normal.

          • Dan the Weatherman

            That is 2006-07 you are thinking of.

        • Cap’n

          Great for skiing but we need that cement and it’s water content. Truckee climate summary shows 199″ for Truckee that year, right at average. That was my second winter here the first few blend together.

      • Dan the Weatherman

        Actually 2007-08 wasn’t too bad for Socal; it was 2006-07 that was so terribly dry. Los Angeles had nearly 8″ of rain in January 2008. My only complaint about 2007-08 is that the rainy season ended basically at the end of February with a bone dry March leading to some ridiculous hot spells in April and May. I absolutely hate having hot spells in April and May.

      • 805 Weather (Camarillo)

        Some of my favorite thunderstorm memories came out of those seasons lol.

    • jstrahl

      2005-6 yes, 2007-8 no.

    • I don’t doubt him. I don’t see a 2005-06 in my mind though. SSTA are not zonal like they were in last winter and 2005-06. Although a quick peek at MEI shows a similarity with 2005-06 and where we are now. NP is still relatively very warm and so is NA. I don’t see much gradient in the NP at all right now…to me that’s scary bad.

      • Pfirman

        Upvote because I agree ‘scary bad’. The chaos may save us because it seems little is really predictable.

  • Cap’n
    • malnino

      Nice pic!! Dramatic ..

    • rob b-Truckee/East Bay

      It’s raining in the upper parts of TD.

      • Cap’n

        My wife is working from home today reporting loud thunder with some rain. Crazy September.

  • Cap’n
    • SoCalWXwatcher

      You guys have all the fun!

    • matthew

      Very close. ~3 seconds from flash to boom. No real rain yet though.

      • Cap’n

        It is eerie in KB on the other side of that monster. Black on top of Brockway Summit in going to delay my drive home for a few.

        • matthew

          There was bad construction delays on 267 on Monday. Avoid if you can.

          • Cap’n

            It’s my life. I enter on 89 in the morning and leave 267 in the afternoon 4 days a week. 89 was horrible today.

    • matthew

      Still minimal rain – but man! – the thunder!!! Probably 4-6 per minute. You can physically feel some of the thunder claps.

      • Cap’n

        My wife said the windows are rattling again. Raining by the airport but not hard, was hoping to follow the rain I got my bike with me. Sky is wicked looking.

        Edit: massive bolt by you!!

    • AlTahoe

      Storms seem almost stationary on Radar. Nothing in Incline or South Lake yet.

    • Tuolumne

      Man, that *is* a beast!

  • mbmattcor (TD 6400′)

    Anyone else notice how 89N above truckee is a magnet for convergence? This is my 4th season up here and it’s down right freaky how stuff develops just west or east of 89N each summer.

    • Cap’n

      They get nailed all the time you’re right.

    • matthew

      It looks like it is sitting over 80 from 89 to the state line.

  • Bombillo1

    I know we all enjoy these electrical shows but these lightning strikes at this time of year are a bad bad thing. The firefight taking place just behind our ranch here is jawdopping. 4 Blackhawks, one Skycrane (I think), tanker, dozers & hand crews. $500K an hour just here I’m guessing. Still drafting out of our pond. Wait till they get the water bill, storage fee, excise tax, standby fee, late payment fee etc! https://uploads.disquscdn.com/images/2ba96f21d3e8731755c6c1ee7760c87a9bf578d27421a5c9d9b9b401f62299ba.jpg https://uploads.disquscdn.com/images/7f0d0839e8218c5ed9774f958ca7cc7e90fe2bf7fc82be0c352f2896a66cc8de.jpg https://uploads.disquscdn.com/images/de7e28f3ae29a09750b52617ea2fa73183a6a80fdf9d0c3fd64184de8dc361bc.jpg I’m worried about the Tahoe area.

    • rob b-Truckee/East Bay

      the ballet those guys do with the aircraft is amazing, all pretty much orchestrated by the Air Attack plane above the fire.

    • Cap’n

      Man I couldn’t agree more. You can become mesmerized by these things but they scare the hell out of me at the same time. These past two days most our storms have been dry but luckily everything else this summer has been wet. If we can make it through today without incident we might be in the clear. I’m in my truck at a trailhead listening to nonstop thunder and it’s just barely sprinkling (there was some wetting rain in central Truckee). Dude best of luck to you and for your property.

      • Bombillo1

        They have beaten this thing into submission. Feeling much better now, but thanks. I was here for the Fountain Fire in 1991 that sprinted 25 miles in 3 days so I am gun shy. That got to within about 1/2 mile of the ranch but burned out everyone. Firefighting is much better these days, I must say..

        • SlashTurn (Santa Barbara)

          Glad to hear they got a handle on it…

          Because im a sort of California fire history nerd, I couldn’t help but read up on the Fountain Fire and its details…Arsonist set the fire at the peak of drought and local weather conditions…full torching of the whole forest and most riparian zones… What caught my attention to this fire was that the land owners (timber industry) did a massive rehabilitation and basically did the first and only private re-forestation on a large scale (post fire), with strict attention to species/diversity placement for full recovery in 40 years…Sounds like admirable intentions, but I wonder if they really did it for future harvest, or do they care about the land and climate? hmm…

        • Pfirman

          So happy for you, and them.

        • Yolo Hoe

          Best news of the day — your pictures of the choppers doing their thing were inspiring — real pros at the helm

    • matthew

      Strangely, I am not all that concerned about fires. Things are still amazingly moist around here. A local meadow about a half mile from me is still moist with water flowing and wild flowers blooming. It is normally dry by July.

  • matthew

    Looks like Incline is getting whalloped now. Al? Been well over an hour so far here.

    • AlTahoe

      Not even a rumble of thunder or drop of rain here in incline.

  • Cap’n
  • Joey B.

    Of course I slept through the lightning and thunder at 4 AM. -.- It also rained in the early morning hours. Enough to wet the streets.

    • Pfirman

      So B stands for bed?

      • Joey B.

        Apparently xD

  • rob b-Truckee/East Bay

    Uhh—what the_______Tornado Warning over Tahoe?
    https://twitter.com/kcraFinan/status/908107083836383233

    • Cap’n

      That thing is like a confused blob, I can’t completely tell where it’s heading, maybe down to SLT now? Good solid rain falling in this part of Truckee now.

    • mbmattcor (TD 6400′)

      bad time to be on a SUP on the lake

    • rob b-Truckee/East Bay
    • Hollow Scene (Riverside)

      Would that be considered a super cell?

  • Great Winter of 2017 (SMC)
    • rob b-Truckee/East Bay

      Pictures coming out of the funnel cloud over Tahoe.
      https://twitter.com/TySteeleNEWS/status/908112044909412352

      • SlashTurn (Santa Barbara)

        Is that cloud over sand harbor on the eastside?

        • Charlie B

          That looks like Crystal Bay with Sand Harbor in the distance (Incline to the left).

  • AlTahoe

    Sitting in the daily 1 hour construction delay by sand harbor currently. No rain but lots of lightning and thunder. South shore looks dark right now.

  • Thunderstorm

    Web cam shows Reno about to disappear into a black hole. Gona scare a lot of folks real soon! Show us some pics of Reno later if you still have power.

  • rob b-Truckee/East Bay

    Video from North Lake Tahoe Fire of the tornado/water spout.
    https://twitter.com/derekkcra/status/908124753398923265

  • Cap’n

    Last of the day, it’s just that the clouds have been so bitchin! Looks like Al left Incline in time. North Lake to Reno looks wild, at least on radar.

    https://uploads.disquscdn.com/images/0faa647eda5159274ce044d79dafbbe62b5e0bdf4f2d024b54c987e8715067b2.jpg

    • Charlie B

      It was crazy on the ground as well as on your radar. I posted the picture below.

    • AlTahoe

      Mom texted me from sparks and said it is crazy there

  • CHeden

    Here’s an observation geared for geeks…
    As of 2 p.m., I was surrounded by numerous isolated towers/storms over the coast range to the west, Shasta/Cascades to my north and the northern Sierra/Lassen area to the east. As of 5:30, not only have ALL the storms quieted down, but everything has simply evaporated/disappeared! ATTM, all I can see are a few high-elevation pockets of alto-stratus which were the blowoff from the earlier storms….but nary a mid-level cloud to be seen.
    One rarely sees anything change in-situ like this so quickly (as compared to a front simply moving past).
    What appears to be occurring is a rapidly progressing dry NNW flow at mid-high levels from the western inflow into the cutoff low off the Cent. Coast. The edge of NNW meridional flow has passed us, should track east following the movement of the CoL core. Given the speed of which our skies cleared out, I’d suspect the Sierra should be quieting down shortly.
    Yup, Fall is just around the corner.

    • Charlie B

      They all hitched a ride down to Reno.

      • CHeden

        LoL!
        Like a wagon train.

        • Pfirman

          I’m thinking the chuckwagon caught on fire and dried them all up.

      • Admode (Susanville)

        They have skirted susanville along the way.

    • Thunderstorm

      Good maybe the humidity will finally return to normal.

    • Dan the Weatherman

      It is beginning to feel like early fall in Socal now with the cooler temperatures and increasing marine layer. It seems to be coming somewhat earlier than normal this year, possibly because summer started earlier than normal as well.

  • Shane Ritter
  • Fairweathercactus

    I am going to keep saying about half the rain we got last winter. 9 inches of rain and much colder. Looks like others are paying attention to what I am saying.

    http://www.nevadaappeal.com/news/local/forecasters-say-repeat-of-2016-17-winter-unlikely-but-it-is-still-early/

    • CHeden

      Or another way to put it, “normal”.

      • Pfirman

        Yeah, but he is usually wrong.

  • CHeden

    VIS nicely shows the drier air moving through Plumas and still advancing to the SE. https://uploads.disquscdn.com/images/d28e1d2d42b6945d902ffeee059fe4d4db438f511758b8dfdd2e090520be180c.jpg

  • thebigweasel

    Lovely here today; breezy and cool.

    • CHeden

      ATTM, 84F here in the north Valley with light/cool southerly breeze.
      Perfect for another Scotch on the deck.

      • Pfirman

        ‘I don’t want another drink, I just want that last one again.’

  • Admode (Susanville)
  • CHeden

    For reference purposes only, here’s the experimental 2-class outlook that was issued in August. The obvious thinking is generally cooler than normal/troughiness over cent North America in the early Winter with moderating temps thereafter.
    Also, it’s striking to note how little overall signal there is as to any definable region for significant precipitation anomalies across the entire West except for a possible dry zone in the SW. Will be looking forward to the next update 10 days from now.
    https://uploads.disquscdn.com/images/349756f241b476e64a43dd97d1e499bbc90e1b09be01916ac3c24f0341ba0a37.jpg

    • Odd, usually warmer temps up and down from AK to SoCal seem to imply a HUGE ridge, which would then suggest, well, you know. Almost looks like someone just rubber stamped each month.

      • CHeden

        Ya, that’s my point.
        Not sure if we’re looking at a lot of high amplitude events (both dry and wet) that simply get averaged out, or we get a constant parade of weak-moderate events. There’s a big difference as to possible impacts to Calif.

        • I don’t see a nail to hang a palatable forecast on. What I see I don’t like

          • Pfirman

            At least you won’t poke your eye out on a nail.

  • Taz & Storm Master

    any one want to take idea on when we will see are 1st area wide rain and snow of the season last year OCT 14 was are 1st storm event

    • I haven’t checked models today, but I’m guessing September 24

    • matthew

      December 11.

    • Thunderstorm

      Last year on October 16th got 1.51 inches here SF bay area by Fremont. subtract 5days it’s on for October 11th.

    • Bombillo1

      In extreme N. Ca. we received 18.45 inches for the month of October. The start was about Oct 7th with a small (.21 in.) event. Changed batteries in all my devices and we were off to the wettest October ever recorded here. 50 mi N. of redding 2500′ elevation.

      • CHeden

        What a month. The precip was mostly from typhoon remnants (Songda, et al) flowing underneath/fueling a couple of bombs in the NE GoA.
        Tough to compare last year to any other year given the anomalous setup.

        • Bombillo1

          It was certainly a one off event not likely to be reproduced soon. The record may stand a long time! Of note however, there were an inordinate number of early troughs out of GOA impacting Wash, Oregon and eventually NCal. I’m looking to see any signs of a repeat of that trough machine setting up.

      • thebigweasel

        If you’re in the canyon, then you’re in one of the rainiest spots in California. Castella averages around 90″ a year. Dunsmuir is close to 70. I bet Mossbrae Falls is still really going strong this year!

        • Bombillo1

          We’re almost exactly the same as Dunsmuir in terms of rain and snow. Those first towns going up the canyon towards Shasta are huge storm funnels. Sims rings a lot out of those systems too. This you & CHeden know but maybe not all.

          • thebigweasel

            Oh, I know it all right. What might be a light drizzle in McCloud is biblical and evil when I reach Sims. And then sedate rain by Mountain Gate.

        • Pfirman

          He is in more of a Pit than a Canyon.
          Speaking of still flowing, Cache Creek, which waters most of western Yolo County via canals, has had flow all summer. I cannot remember when that last happened.

  • matthew
  • Nate

    More thunderstorm video from Monday. Was able to get a couple of CG strikes in the afternoon, but the real show was the lightning (mostly CC) at night over the Diablo Range.

    https://youtu.be/_9wOAecFj-Q

    • Jim (Watsonville)

      Great video !!

      • Nate

        Thanks!

    • Great!

    • Tyler Price (Carmel Valley)

      Wow!! Very nice!

    • Hollow Scene (Riverside)

      You win this time Bay Area… ?

    • 805 Weather (Camarillo)

      Epic!

    • Sokafriend

      Awesome!!

  • Great Winter of 2017 (SMC)

    Boring and cool weather for seems like an endless period, would rather have hot weather and thunderstorms, still can’t get over how insane those storms were Monday!

    • molbiol

      Same here. Just took a look at extended models and it looks like 20+ days boring weather with annoying winds for Lancaster. Still hoping a cutoff low or two will impact the area during October which in the past has produced severe weather. Until then weather will be taking a back seat for me

  • Unbiased Observer

    Random pop up thunderstorm in the area predicted by the HRRR and came to fruition, didn’t quite make it to my house but the airport picked up .5″ with some hail and saw a decent light show from atop the bluffs here in Bakersfield.

    • Mike

      Anyone able to explain the dynamics behind this event?

      • Unbiased Observer

        Not me! My only thought is there must have been some unstable air and the daytime heating finally broke it through (even though it was at night). Doesn’t really explain why except that the low passed directly overhead.

      • Thunderstorm

        The low that did not pass over the bay area went south and then inland. Bingo. Also could be some moisture around as Bakersfield got some hefty rains recently.

  • palmsprings

    FINALLY, I CAN BREATHE AGAIN!!!
    Needless to say, eagerly looking forward to double-digit highs! It’s so nice to be able to open the window/door and feel crisp fresh air instead of the incessant burning heat day or night!

  • David Mata

    I usually refer to an extended period of June Gloom in September as “September Somber.” 1986, 1988, 1998, 1999, 2001, 2005, 2007, and 2011 are perfect examples of Septembers (in So. Cal.) that experienced an extended period of cool, cloudy weather. And we seem to be entering one this year.

  • RunningSprings6250

    Yesterday low of 61, this morning low of 40 with 94% RH low clouds/fog.

    FALL IS HERE!!!

    Extended forecast shows highs in low 60s at best and even a high of 52 next Tuesday or something.

    LOVING IT! We had an early and long summer so this weather has never been more welcomed!

    • Los Padres NF/ Piñon Pines

      Same over here on the Frazier Park mountain area/ mt. Pinos. Highest temps we see is this weekend at 72/71, then all next week is in the low 60’s with a low at 42!! Feels great. Totally agree fall is here!

      • BRP (Ventura)

        Stoked for you “mountain folk”! Hope you guys receive cold morning temps throughout the Fall Season. Looking forward to getting up on top of Mt. Pinos this winter, on a weekday of course, due to that place being “discovered” and turning into a human zoo on the weekends….sad…

        • SlashTurn (Santa Barbara)

          *sigh* yup those hidden gems pre social media are fully compromised. But like you said, weekdays are still empty

          • 805 Weather (Camarillo)

            Sadly…

        • Los Padres NF/ Piñon Pines

          Yeah the crowds got a little crazy last winter. Residents got fed up, at one point once you drove a bit into the mountain off the 5 chp had a check point, if you didn’t live there they turned you back around. I think it’ll be a bit more under control this year. But I would still suggest chains. Check point or not chp will pull you over, check for chains and ticket people or turn them back around depending on the type of truck, a car is definite ticket

    • SlashTurn (Santa Barbara)

      Sick! I’ll be in your neck of the woods hiking up Gorgonio on Tuesday. I’m looking forward to freezing temps…

    • Dan the Weatherman

      I am glad that you have confirmed that this summer started earlier than usual!

  • CHeden

    If there’s one thing that’s sticking out in the MR/LR forecasts, is the quasi-stationary high pressure that keeps reforming out around -140W before finally inching towards the coast late in the period.
    As the high shifts east, all of California will be under a very dry NNE flow and increasing temperatures….especially for those locations subject to katabatic warming (i.e. Santa Ana’s).
    Given it’s mid-late September, not surprised that a widespread north-wind event might setup….which is “normal”….but this one may be a bit more robust than usual.
    ATTM, the heights associated with the H.P. are still unclear, and we probably will have to wait until the high starts to shift east before making a call on on the strength of the advancing ridge, and how hot and windy things will get.

    • CHeden
      • Zonal flow across PacNW and dry everywhere else. That’s winter right there.

        • 805 Weather (Camarillo)

          You could be right lol.

      • 805 Weather (Camarillo)

        Nicely done! This is what I’ve been watching for this first half of the month. Not what I’d like to see though.

    • Thor

      Learn something new every day…I had wondered what this local brewery’s name meant…now I can drink with a knowing confidence 🙂

      http://www.katabaticbrewing.com/

      It all makes sense as Livingston is one breezy town…as the brewer’s motto says “A Drinky Town With a Wind Problem”

      • Pfirman

        Is this it’s third brewery? A drinky town indeed.

        • Thor

          I only know of 2 in Livingston but Bozeman has 10! not bad for a town of 45,000

          • Pfirman

            I have been to the one with the ocean theme, which still confounds me. 2 / 7000 in Livingston is higher density than 10 / 45000 in Bozeman, but both smash Woodpile with its 1 / 60000. Still, it only takes one to get ‘drinky’, heh.

          • Charlie B

            I saw that one of my favorite places around, Big Sky, is set to get 1 foot of snow up top.

    • Well we all wanted a quick transition to winter. LOL turning to tears

    • Dan the Weatherman

      I think we are starting to get into a fall pattern a little bit earlier than usual. Like I have been saying, this summer started earlier than normal, so it seems to make sense that the pattern is changing early as well. In this case, I wouldn’t be surprised if we get a Santa Ana event a bit earlier than usual. The first widespread Santa Ana event doesn’t usually occur until early or even mid October, but I have seen them a couple of times here in my part of Orange in late September, although that is fairly rare.

  • CHeden

    Here in Cottonwood, a dramatic shift towards Fall is underway. This morning featured our first dew on the cars, and get this, low stratus is forming around 2,500’…the first time we’ve seen anything resembling fog-like cloudiness for the last 6-7 months. Temp is running 66F after bottoming out at 64F..the chilliest we’ve been so far. With the inversion overhead, aIr quality still sucks, as the atmosphere isn’t mixing out…but with general troughiness on the way, maybe I’ll be able to see Shasta again in a few days?

    • Pfirman

      Judging by your other post talking about hot and windy this “dramatic shift towards Fall” is just a feint to lull us into good cheer.

    • AlTahoe

      It was in the low 40’s this morning in South Lake Tahoe but when I got up to the junction of 28 and 50 at around 7k, the meadows up there were totally frosted over. First big frost of the season.

    • 805 Weather (Camarillo)

      Noticed this as well on the western slopes of the Sierra foothills this morning! Hopefully showers on the way to aid FF’s up there.

  • happ [Los Angeles]

    NWS_LA is calling for a deep marine layer as of 2 hours ago yet skies are still completely clear over Los Angeles and nothing out over Santa Monica bay. Weak ridge may be the cause.

    Wednesday: 81/ 65

  • AllHailPresidentCheetoJesus

    The marine layer came in early last night (6:30ish), hadn’t seen it come in so early since we moved to the concord/pleasant hill/Martinez area… It was freaking awesome…

  • 82/83 El Nino baby (San Jose)
  • Thunder98 (Santa Maria Valley)

    NOAA issues an La Nina Watch. (55%-60% chance of forming this Fall and Winter)

    http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.shtml

  • Thunder98 (Santa Maria Valley)

    Went down to 59F very early this morning! Been 2 weeks since the last time it went down below 60’s. The dew points are in the 50’s more often than not now too. 🙂

    http://www.wrh.noaa.gov/mesowest/getobext.php?wfo=lox&sid=KSMX&num=72&raw=0

  • Cap’n

    Sure would love to see this same thing in December and January, but we all know the heat is coming back, that’s One thing we can always depend on.

    https://uploads.disquscdn.com/images/b27a9ee5cff1ef21c114534a57b3a3402a3b1085e8e7171be2407e0ca09c2fa7.png

    • AntiochWx

      I think the big heat is just about done, can’t rule out above average temperatures for October- December, but the 92+ temperatures look to be over for most. Now let’s all enjoy the autumn cool down 🙂

      • Cap’n

        I’m stoked on the cool down, can’t be cold enough for me, but I saw posted below that a heat wave is already on the horizon, so instead of living in the moment I’m unpacking my tank tops and cut off denim shorts that I stored in the shed just yesterday.

    • Fairweathercactus

      Get a jacket cause Cactus might turn into an ice plant. Cold and dry one.

      • Cap’n

        Cold/dry or warm/wet and anything in between. Experts assure us it will in fact do something.

  • AntiochWx

    Yesterday was a high of 80! Boy did it feel great, spring and autumn are my favorite times of the year.

  • Thunder98 (Santa Maria Valley)
    • Hollow Scene (Riverside)

      Same thing here, what a change

  • alanstorm

    First one of the season on Tues.
    Del Norte always gets it first.
    A sign of things to come…
    Inside slider?
    https://uploads.disquscdn.com/images/567d33f800fd1d1ccdfcbf8c8d2d7289dadf9a1cb0381c06b92cca2119f8d62c.png

  • Thor

    As if we needed more confirmation of a transition; winter storm warning just posted for SW MT. It was 90 on Tuesday…currently 45 and a nice, steady drone from the rain.

    • Cap’n

      A buddy of mine just moved to Sheridan WY. Same there. He was complaining of the heat n smoke two days ago so I took a screen shot of their NOAA 7 day, what a switch!

  • Great Winter of 2017 (SMC)

    Who wants to be bet, will October be wet for NorCal or not?

    • Yes.

      • FolsomPrisonBlues

        I think so

    • Tyler Price (Carmel Valley)

      I’ll bet on it being a wet month for NorCal.

    • alanstorm

      All that’s needed is for THIS action to slide a bit south….
      Good to see there’s ample moisture in the GOA!
      https://uploads.disquscdn.com/images/71462ffedc069750d00ac68bec43d53c7fef389f29904937f8341a4b516f02ca.png

    • We lost the hot or not for August. I’m in for not and knot and naught

    • PRCountyNative

      Only at the very end of the month. I picked a date a few months back.

      Very norcal is always wet, middle and southern norcal are what everyone thinks about as Norcal. North of the Golden Gate. I guarantee Humboldt will be wet.

    • jstrahl

      If i was a bettor, i’d bet “not.” But then, i’m not. 🙂

  • AntiochWx

    Today was just awesome, much drier and a noticeable drop in dew points. Days with DPs over 63 really suck., glad today wasn’t one of them. https://uploads.disquscdn.com/images/63003c4684d91e4d6f5a9e7f8a4b012b2fc62c00680c9b0aa33bb2feb47c1094.png

  • Nate
    • 82/83 El Nino baby (San Jose)

      Only a couple miles from my house. My wife went and bought supplies as she is convinced the big one is imminent. This is after I tried to explain earthquake clusters are normal.

      • AntiochWx

        I don’t think one is imminent, but a 5.0 or higher does have a elevated probability of happening over the next century. I don’t worry about it too much about it, mainly because we have decided to purchase earthquake insurance. Eventhough it’s very expensive, it’s worth every penny to us, if for nothing else for the great peace of mind it brings.

        • Pfirman

          Do you have a chimney?

          • 82/83 El Nino baby (San Jose)

            I do. Brick unfortunately.

          • Darin

            In the 94 Northridge earthquake, brick chimney separation from the house common. There’s no cheap solution and earthquake insurance is a rider on the main that few had or have (<20%). The SFV(general area) had a lot of "pure" fireplaces i.e no gas. I heard everything from "we'll fix it when we sell" to "we've got this draft now" to "we just knocked it down and covered it ourselves". /SMH

            Of course now I'm a homeowner, I can relate.

          • AntiochWx

            Earthquake insurance is ridiculously expensive. We elected for 5%. I don’t want to rely on FEMA loans in the event a 6.0+ earthquake damages our home. I understand why 70% of Californians don’t have earthquake insurance, but I’m not about to let such a huge lifetime investment be possibly destroyed with no safety net.

          • inclinejj

            That’s why it should be exactly like flood insurance. The closer to the Fault the higher the premium. Mandatory Flood Insurance has really come down in the last 10-20 years but thats due to cities doing more to prevent flooding. I’m not a fan of the insurance industry but they are a necessary evil. $1,000 to $2,000 bucks a year to protect a million dollar investment. Actually we received a big discount on our home policy when we added earthquake insurance.

            I remember the State Of California talked about this years ago. Not sure if they actually did anything.

            With Harvey and Irma insurance industry losses, we can all expect higher renewal rates next year. Even though policies are all covered by reinsurance.

          • Pfirman

            Take it down?

          • AntiochWx

            Yes

          • Pfirman

            It seems like a disconnect to have insurance and also have a chimney. Friend who lives on Hayward fault took down his chimney to avoid having it kill him. I was in a big quake in Seattle in 1965 in which three people died from falling bricks.

        • Thunderstorm

          If it happens you will wish you had boots and gloves and at least water for a week.

          • inclinejj

            Just as important is making sure you have at least a weeks supply of your prescription medications.

      • That’s easy for you to say. That’s quite a cluster on an active fault. https://uploads.disquscdn.com/images/cdfc48c42d2e5b807612f2285ab1100ab0b5390ccd05a19104a206027d51007d.png

        • Nate

          Eh, pretty routine for this area. Something to watch though.

    • Great Winter of 2017 (SMC)

      Nope, I do always wonder when the big one will reck California

      • AntiochWx

        It will probably happen is one of our lifetimes, especially for those younger than 40. I hope Californians are ready for that dredful day.

      • Nate

        According to the USGS, there’s a 72% chance of a magnitude 6.7 or greater quake in the Bay Area within the next 30 years. Be it tonight or 50 years from now, it’s going to happen at some point.

        • Tuolumne

          We could easily end up with several in that size range during the next 50 years. None would be “the Big One” (a hugely misunderstood and overused term), which would be a repeat of 1906. That repeat is probably not imminent, but it’s also out there in the future somewhere.

          But it’s the Loma Prieta/Northridge-sized quakes that are the more immediate issue in the Bay Area. A direct hit (unlike the relatively distant Loma Prieta event) could kill thousands. This area has 20x the population that it back in 1906.

          SoCal is a whole different story. Their Big One on the San Andreas truly is due or overdue.

          • Nate

            Yes, the Hayward Fault is capable of far greater damage than what the San Andreas could do in the Bay Area, even with a 1906 repeat. Same with SoCal, as a well-placed quake on an underlying thrust fault could rival/exceed casualties and damage costs of a large San Andreas rupture.

            There are issues with saying that the SoCal is “overdue”, but yeah, it’s going to happen, and when it does, it’s going to be bad. Be prepared!

          • inclinejj

            Hayward Fault has the potential to be just as dangerous as the San Andreas Fault. If I was going to drop money I’m betting on the San Andreas between Paso Robles and Parkside up to near Salinas.

      • Hollow Scene (Riverside)

        I think everyone should have a few earthquake supplies in their trunk, at the very least some water and a flashlight

  • Great Winter of 2017 (SMC)

    People tell me climate change doesn’t exist, explain how my town averages 10-11 days at or below freezing every year and we haven’t had one day at or below freezing since winter 2013-2014. Really

    • SacWx

      Good news is polling shows less and less climate change deniers.

      Bad news is very few are willing to sacrifice much of anything to do anything about it.

      • I’m populist to my core. I believe that climate change is occurring, but no one – I mean NO ONE – is going to alter life style – and I am not even talking about the great masses of Asians and Africans who expect and deserve a better quality of life.

        So the sermons just won’t work. Forget Al Gore’s bonfire of the vanities. Savonarola ended up burnt at the stake. People are no better than they are, and why should they be?

        Look to energy efficiencies and prepare to engineer around it. Boston may look a great deal like Venice a century from now, which is not the worst thing I’ve heard recently.

        • Nathan

          dude what are you talking about, if we all use biodegradable shopping bags our problems are solved

          • Pfirman

            Brutal.

      • Chris

        Is that poll true?!?!?!?
        If so, that’s the best news I have heard this year!

    • Darin

      If you Google “boomerang effect antivaxxers”, you’ll get your answer. Unfortunately, it might depress you…a lot.

  • Admode (Susanville)

    Pretty sweet lightning storm in this draw https://uploads.disquscdn.com/images/53418722cbc82b4e4ae684a9c6eae36ad35d699ab8e7613791a6a48056f66cf3.jpg this afternoon. Coleman Lake, ca.

    • Bombillo1

      All lakes are becoming meadows and all running water becomes shallower and wider, with time. We need another ice age to re-excavate. Coleman Lake is a great example of end stage sedimentation. 1000 years from now it will be a meadow with no water. Still pretty in its own right.

  • Bombillo1

    http://www.businessinsider.com/vegetables-grains-crops-climate-change-effects-carbon-emissions-2017-9

    Another consequence of 414 ppm of CO2, vegetables and grains are now containing elevated sugars. Plants indulging in the CO2 availability are creating excessive sugar. Not only do we add the shit to everything but our traditional refuge of vegetables are going junk. Go long on type 2 diabetes drugs, there’s bright future there.

    • Sokafriend

      All veggies and grains? Does geography and growing method make a difference?

      • Bombillo1

        Since air gasses are well mixed CO2 is quite evenly distributed, consequently geography makes no difference. Hard to grow anything anywhere without being influenced by ubiquitous CO2 .

      • Certainly geography and growing methods matter, but this effect is apparently pretty widespread across most plants.

    • Nathan

      Wouldn’t the flip side be that we need less arable land to grow the same nutrient resources?

      • Bombillo1

        The gist of the article is that plants are creating more sugars but less protein and nutrients. It is a win for trees or decorative species but not for things we eat.

        • Nathan

          heh, the Politico article was called “The Great Nutrient Collapse”, and much of the findings are drawn from a 2014 Nature paper which found that in some C3 metabolism plants, but not others, (not C4), specifically Iron, Zinc, and “protein content”, dropped in the realm of 5-10%. This is when grown in [CO2] of 560-580ppm, so almost 50% higher than current levels.

          “Collapse” indeed…

        • Pfirman

          Upside is celery for dessert.

    • SlashTurn (Santa Barbara)

      I believe the greater collapse of nutrient dense vegetables is from poor top soil
      management with the monoculture industry. That is the bigger issue IMO…the widespread planting of single plant species degrades the air, water, land. Along with the unnecessary use of herbacides/pesticides/GMO it’s a mess…

  • 805 Weather (Camarillo)

    The REAL bet was on how long the snowpack would last & if it would make it long enough to see the first flurries of the next season to keep it building… Hmmm.

    • Cap’n posted a pick a few days ago. There’s protected areas above 9500 ft that have snow. I don’t see it that important other than a bet. Gotta get spring and summer temps way down up there for decades.

      • 805 Weather (Camarillo)

        Unfortunately true.

  • thebigweasel

    I posted on global warming and hurricanes just the other day.
    http://readersupportednews.org/pm-section/27-27/45751-bigger-stronger-storms-take-it-to-the-bank
    Feel free to pick it apart.

    • PRCountyNative

      Thank you for sharing.

      So the science is clear; rather than try to convince people, maybe wonder why people are so hard to convince. Facts have nothing to do with it at this point. It’s not about making an argument any longer.

      • There a people with a vested interest in climate change not being real, usually the private sector, and they are spending their money and effort to make global warming “not a thing”. It’s in the best interest of their wallet, and they are doing their absolute best to put politicians and laws into place friendly to those interests.
        Our coal-hugger of a president is so very wrong – be a tree hugger, not a carbon monkey.

        • Pfirman

          Just to be clear, carbon monkey is not the same as cord maiden.

    • Darin

      Very nicely done. You provide data, context, and explanations.
      You asked for us to pick it apart. My nitpicking… (One really is a nit, it’s small round and can be easily missed) There are no zeroes before the .2 and .4, also it’s a rate so what’s the time. It’s a stylistic thing but I read to quickly. I read 2 and 4 degrees. Also, if it’s a nominal value okay but I’m guessing it’s a rate so what’s the time frame. “Between 0.2C and 0.4C per year”. Also, the last sentence/paragraph is both a run-on and an analogy. I love analogies though this is a science paper. Additionally, you have moved off from explaining and onto sympathizing. I feel the same way you do but it’s not the point of the article. You made the point – “No ifs, ands, or buts.” – but kept going. . Consider removing the last sentence/paragraph completely as the idea could be a different post all on its own i.e why scientists don’t predict.

      I learned from it; I can explain to someone else where and why they happen; and I can explain to someone else why climate change will increase hurricanes. Well done.

      • thebigweasel

        Many thanks. Your points are all valid. That last paragraph was rewritten (the original could be read as blaming the scientists, which I was certainly not trying to do!) and got clunky as a result. You’re right; it adds nothing and could go.
        I’m glad the main objective was achieved, though.

  • Great Winter of 2017 (SMC)

    54 F at 7:10! Low bottomed out at 53 F which is coldest in quite some, Fall bring it on baby!

    • Jason Jackson Willamette

      Yeah. Amazing how it’s changed. I welcome CHANGE! Ugh, as long as it doesn’t affect me in a negative way…. humanities mantra –

  • AlTahoe
    • Jason Jackson Willamette
      • rob b-Truckee/East Bay

        a few highlights from the NWS Reno AFD-

        “Today will be the coolest day of the past three months as dry
        north flow prevails…”

        “Additional systems for Wednesday-early Thursday and possibly Friday
        will bring gusty winds and perhaps a better chance for showers. Snow
        level could dip down below 7000 feet at times, which may leave a
        light accumulation of snow on mountain peaks.”

  • Thirstier Nick (Santa Maria)

    Back in the mid-50s this morning. It’s been quite a while.

    • SlashTurn (Santa Barbara)

      Its so nice to be under 60F at night along with the low DP…I can finally sleep!

  • Thunderstorm

    Back to warm again for bay area middle of next week as high to north builds in behind trough.

  • RDLA

    Got some heavy drizzle/light rain in Palos Verdes this morning; nothing that seemed to appear on the radar but a really nice change.

  • Charlie B

    As noted below, there might be a dusting of snow on the peaks around Tahoe next week. Also, the Northern Rockies in Montana are getting some early season snow. (One Big Sky webcam at 8800′ shows big flakes as well as a big sky.) That said, September snow is not uncommon. In 1986, Echo Summit recorded 26″ and in 1985 there was 17″. Bodie has several 12″+ years. Due to the change in water year, I think anything that falls this September will be “credited” to last year (unless snow totals still go on the July 1-June 30 season, which makes more sense for all stats in this part of the world, obviously.)
    Finally, from what I can tell quickly, there is scant correlation between September snow and what eventually happens later in the year. For example, the 1985-86 year was a good one (with the big February flood), whereas 1986-87 was a 65% year.
    Hey, it’s Friday, so few are commenting…..

    • rob b-Truckee/East Bay

      You are correct, normally no correlation between early snow and “big” winters. Just a few years ago we had snow during the short lived Tahoe Ironman in late September. There was just about no snow the rest of that winter. I do remember a big storm around 2003 that saw measurable snowfall into Reno in mid-October and that winter ended up being good. BA at Opensnow has made mention of this before to not really get excited about snowfall until November because what falls before that tends to melt off within a few days.

    • Amy Cohen

      I’ll have to check my log book, but I think I had to start my first fire Oct. 1 last year here in Olympic Valley. I’m still busy splitting wood using the safer reverse/inverted method with a thick hammer. I’m not even close to being prepared. I really have to push myself to finish before Oct.

  • Charlie B

    In the last 3 months in Reno, there have been 2 days with below average daily temperatures and 26 days where the daily average was 10 or more degrees warmer than historical averages. Warm overnight lows played a large but not sole part, since we also experienced a record number of 100+ highs.

  • Sokafriend

    Catastrophic and existential-
    See new Scripps CC report

      • Pfirman

        “We would never get on that plane with a one-in-20 chance of it coming
        down but we are willing to send our children and grandchildren on that
        plane.”
        Current national leadership in a nutshell.

        • Get 3-5 day forecasting right 95% of the time first.

          • jstrahl

            Long term is easier in many ways. Like when flushing a bowl, easier to tell what it will look like five minutes later than five second later.

          • AntiochWx

            Weather predictions does NOT equal climate predictions, this is a huge major talking point that is incorrect and adds to the disinformation.

        • celo

          I think statements like the one above creates political polarity and do not allow growth of pure scientific thought. Maybe humans can only learn if they are manipulated emotionally. I believe emotions should stay out of science if we are to understand clearly what climatological direction we are on in the future.

          • Pfirman

            So which is worse to you…..defunding science as our current national leadership is doing, or making statements?

          • celo

            Both are terrible. Defunding the growth of scientific thought trumps all bad future moves. Humanity only grows with strong, open minded, fully vetted scientific processes. Strength usually comes from financial backing.

          • Pfirman

            That is a strong statement.

          • AntiochWx

            I think adding an emotional and political construct around AGW is important. Because science alone is not a great motivator in enacting change. People are stubborn and will bury their head in the sand, sometimes you need to give a swift kick in the behind. Majority of the world’s population is incapable of understanding basic mathematical and scientifc concepts, and something as dire as changing our Earth’s climate cannot wait around for those people to become enlightened unfortunately.

          • AntiochWx

            People are so emotionally attached to AGW because of the ramifications it has if very little is done about it. Honestly, the lifestyle changes have to happen, and people are fighting it. This causes the political polarity, because a vast majority of those that identify with the right are against any major societal changes in regard to AGW. It’s a problem that people are not putting up with and are getting impatient and angry about the inaction. Unfortuntately it shouldn’t have to come down to that, but people are very frustrated.

        • AntiochWx
      • celo

        I completely agree that we are warming and there will be problems for populations around the globe because of it, however traditionally, over the last 2 million years, this is the time we begin entering an ice age and I would like to see a report detailing if we did nothing and entered an ice age. Implications such as, Ice caps covering our big metropolitan areas, colder climate and much poorer crop production around the globe, desertification where none exist today. Proof of these issues in our climatological/geological are easy to find (15k years ago) and would pose great risks to humanity at it’s hugely overpopulated state throughout the globe. Please let’s give alarm/research to both possibilities of the last 100 years of rising temperature trend and the recent catastrophic historical implications of ice ages.

      • Sokafriend

        Thanks for the link- I was crossing the border as I posted.

  • Thunder98 (Santa Maria Valley)
    • FolsomPrisonBlues

      WeatherBell is predicting the same for us as well. I will definitely take average rainfall over some of the recent drought years.

      • rob b-Truckee/East Bay

        average would be great, the lakes would/should refill like they normally do and hopefully no major flooding. I’d take that…

        • FolsomPrisonBlues

          Agreed. I would love to avoid another Oroville-type scare, anywhere in the state.

      • Bob G (Gustine)

        I see quite a few of those predictions. Less zonal flow. Colder storms with snow carrying less water content

    • Those are probability of above or below. It’s a true coin flip nothing else.
      If you want you can play around with the probabilities here.
      http://iridl.ldeo.columbia.edu/maproom/Global/Forecasts/NMME_Seasonal_Forecasts/precipitation.html

    • Bombillo1

      I always have trouble with these color coded graphics. So the upper map shows all of Ca in a clear or no color area. Gray areas are normal. So did they just punt on this or is Ca unknown?

    • alanstorm

      Didn’t the HIGH on steroids & subsequent record CA heatwave have something to do with Harvey’s catastrophic stall?
      (& a lack of Jetstream steering current/ link to Arctic warming as well)
      I realise these are far off extrapolations, but they can’t be simply ignored if they manifest during a period of record heat

      • Charlie B

        My experience watching hurricanes over the years is that they hit land, do their destructive wind, wave, and rain thing, then quickly weaken and move north, oftentimes with the remnants bring absorbed into jet winds and dissipate after causing heavy rains and sometimes catestrophic flooding (see Camille) far from the ocean or GOM. Harvey stalled and then went out to sea and made a second landfall. Therefore, it seems that Harvey’s extreme performance was due to the lack of steering or blocking and not that there was something sinister (wetter) about it. I’m probably all wet, I know. But it is a delightful fall afternoon in Reno and I am sitting on the patio of a nice tap house by the river…..

    • Nathan

      poor Barbuda

  • Thunderstorm

    Nice blue blob in the GOA where the RRR was a few years back. I see they are working round the clock now at Oroville. Looks like a busy bee hive. If the blue blob gets much bigger just may be early start time for rain.

  • 805 Weather (Camarillo)
  • Nate

    Irma loop:

    • Nathan

      mesmerizing

  • Nate

    Does anyone have any information on the skill of the NMME Model? Just been looking at it and noticed it has a common theme with the CFS for this winter, wetter OND and drier JFM.

    • 805 Weather (Camarillo)

      So basically 2016-17 redux?

      • Yolo Hoe

        And maybe a bit colder given the speculative set up? What a glorious ‘average’ winter that would be

      • Nate

        Hmm…not sure, as January and February are shown as abnormally dry.

        • Don’t forget the CFS from Weatherbell showed very dry conditions Nov-Feb and we all know how that turned out last Winter.

      • jstrahl

        The 2016-17 prediction was quite off regarding February-April, and January was shown wet, but nowhere near as wet as it really turned out, nor as far south.

    • Bob G (Gustine)

      Last year it did the about the same thing this time of year. Daniel actually posted graphics from the NMME model last year in one of his fall updates about the upcoming winter.

    • Great Winter of 2017 (SMC)

      This is its model prediction in September 2016 for Oct-Apr 2016-2017 https://uploads.disquscdn.com/images/50927ffd12de5cc91b5348516618ab23cd49d404f4e8642ed492d3882f88a4a7.gif
      This is it’s model prediction for this September for Oct-Apr 2017-2018 https://uploads.disquscdn.com/images/e1691b36df565ad6d1fd58173cd2273b4f8272560fe9960111dae8583c90bbed.gif
      Looks similiar to me!

      • jstrahl

        And last year’s call was WAY off.

    • Chris

      That sounds like typical La Niña

    • SacWx

      Not sure about the NMME, but the CFS seems to change on a daily basis. Can’t have much confidence in these models… at this range I still think ENSO is the best predictor but even that is minimally directional at best.

  • Thor

    Snowing pretty good at Bridger Bowl in case anyone wants to see:

    https://bridgerbowl.com/weather/webcams

    • annette johnson

      I can pretend to cool off for a moment??

    • SacWx

      Saw this earlier today – plan on taking a trip to go riding there later this year.

  • CHeden
    • Gotta love that donut hole.

      • happ [Los Angeles]

        “Gotta love that donut hole”, NOT.

    • Dan the Weatherman

      That looks to be a Fantasyland run and even if it verifies, it wouldn’t be abnormal for CA to be dry on October 1, but I don’t know about all the monsoon activity over the SW since it is late in the season for that unless that is tropical system remnants. If that is tropical remnants I would hope it shifts west into CA!

      • CHeden

        Agreed.
        Not exceptional by our “typical” October standards….but not suggestive of anything unusual (like last year) either.

        • jstrahl

          FWIW, i did no measure any rain last October till the 14th. Ended up with 3.54 inches, vs 1.14 average.

          • CHeden

            Love those typhoon remnants.
            We can only hope we get more of those…..
            but don’t count on it.

          • jstrahl

            Not remotely counting on it. I’m predicting 10 inches for the season (for central Berkeley). Yes, i know i predicted 15 last time (did so at end of October) and got 40.

    • AlTahoe

      We are at about 1000% of average rainfall for August and September in my neighborhood, so a dry end to September would make sense. I think we have been above average on precip for 11 out of the last 12 months up here. It will have to end at some point. I am going with a below average Oct state wide with warmer than average temps.

    • Thirstier Nick (Santa Maria)

      It’s still better than any point between October-April.

  • Thunder98 (Santa Maria Valley)

    Feels like early fall today and the morning lows are cooling down quickly!

    https://uploads.disquscdn.com/images/beb0ede477884c5587d30f8aee66d508dc2953318b75db501a8e77234cfa7665.png

    • hermit crab

      Carpinteria actually feels like Carpinteria!

  • CHeden

    A few notes (commentary) in hindsight on Irma and other recent events regarding global warming:
    I think that that the media, and partially the climatology community in general is failing to articulate what exactly contributed to Irma’s strength.. as well as the exceptionally long-lived/stationary Harvey…plus our”record” western heat this Summer (don’t call it a “heat wave”…our atmospheric base state over much of California all summer has featured higher than usual heights and it’s commensurate weather effects to one degree or another).
    Here in the novice sector, we tend to look at the end-results (like a storm or long period hot/cold trends) as the key evidence of GW or not. This is a mistake. A big mistake. (with all due respects to Daniel’s recent re-tweets and commentary about direct end-result cause and effect between atmospheric pollution/AGW and extraordinary weather events. What’s missing in the message is discussion on HOW changes created by pollution effects the atmosphere’s base state…which IMHO is the link between pollution and the intensity/characteristics of end-events like hurricanes/droughts/extreme heat (and cold).
    That being said, in looking back on Irma during her maximum intensity period, we noticed that the core pressures were not as low as expected given the observed 185+mph sustained wind speeds with “only” a 931-926 mb core pressure. At the time, we noted that the accelerated winds (and Irma’s strength) was possibly due ( in part) to the pressure differential between the core and massive/exceptionally strong high pressure in the NCent Atlantic….which in hindsight (IMHO) is exactly what happened given that Irma’s speed gradually decreased the farther she moved away from the HP core despite core pressures that eventually fell to 914mb when the max winds were “only” 165 mph. Therefore, it was the strength, size and location of this High that likely had more to do with Irma’s eventual strength/ track and resultant destruction than simple SST anomalies and favorable sheer profiles that transformed an otherwise ho-hum tropical storm into a tempest.
    Given that the High was present/stationary long before Irma was born, we now must look backwards in time as to what caused/is causing Atlantic High Pressure to gain such size and strength to help explain why Irma became what she did.
    IMHO, it’s therefore critical to focus (through the media and research) a better understanding of how a High Pressure like this could/did form….and whether or not the areal coverage of High Pressure systems are increasingly getting bigger and more dominant over time (which as many here on WW know is my contention). Within this answer lies the missing link between pollution and end-results like the sensible weather we observe (and experience).
    While I do not in any way pretend to be an “expert” nor profess to be, my 60+ yrs of observation of weather tells me that High Pressure is increasingly dominating the northern hemisphere. Instead of seeing transient Highs/Lows progressing in march-step west-east like before, we now see mega-Highs setting up with low pressure systems forming more frequently as part of a Rex block or Omega blocks than the clash between warm/juicy air and cold northern air.
    So, what is causing these High Pressure systems to form in the beginning? Easy. the atmosphere (overall) is becoming more stable as the troposphere aloft warms. (not necessarily above the tropopause which is actually cooling since re-radiated IR from the planet’s surface is being confined by pollution to lower elevations).
    So, this is the link between AGW and storms like Irma/Harvey and our record-shattering long term heat here on the West Coast. Put crap into the air, and the atmosphere becomes more stable. This results in massive and intense High Pressure systems to form and persist, which in turn can help fuel storms/AR’s that form…but only around the High’s periphery.

    • Chris

      You brought up points I have never thought of before.
      I didnt know that high pressure systems are growing stronger and more persistent.
      Could we also attribute this fact to what seems to be wetter SW summer monsoons and drier winters?
      Thanks for your insight.

      • CHeden

        Overall, yes. It stands to reason that increasing H.P. in Summer over the NA SW will periodically result in more robust incursions of juicy air around the High. Weaker High, less moisture feed…and vice versa.
        Now, consider our EPAc High in Winter. A bigger High, and storms/moisture gets shunted north around the high, except on those rare times when the ridge fluctuates/retrogrades, which can put us on the narrow edge along the ridge (where all the action is). IMHO, we got lucky last year by staying east of the NPAc ridging.

        • Great Winter of 2017 (SMC)

          So what r u suggesting, less wet winters or more dry and then really wet winters?

          • CHeden

            Overall drier Winters, except when Pacific H.P. aligns just right and we get pounded…i.e 2016-17.
            If u think about it, if the jet/AR’s last Winter were a mere 150 miles further north, we’d most likely have gotten bupkis. It’s not like we got nailed by a parade of storms if you’ll remember.

          • Great Winter of 2017 (SMC)

            Well yes it wasn’t continuous storms, but the longest we went without precip during winter was 7 days so by CA standards it was very consistent. We’ve had several other years with more rain here though. This winter will be interesting, I will be experiencing crazy weather in the future caused by this last generation for a long time

          • CHeden

            Waves/moisture plumes within a persistent mean flow don’t count.
            I doubt we had more than a dozen actual L.P. passages all Winter.
            Compare that to a more “typical” 30+ or so such events we used to get. Many of us “old timers’ remember the Harry Geisse 3 day cycle…which used to be amazingly accurate (at least for NorCal). Now, like you said, it’s more like 7-10 day cycles.

          • Great Winter of 2017 (SMC)

            Interesting we had one of the lowest pressures of alltime recorded in CA this year

          • CHeden

            You are correct. A perfect example of accentuated High-Low differentials (not dissimilar to what I described earlier about Irma). Anomalous setups are certainly possible…but that was not the case for most of the Winter….nor should we expect these type of patterns to counter the overall quiescent atmospheric tendencies that continues to evolve.

          • AntiochWx

            It is really difficult to say for certain. Mainly because if we get into an abnormally stagnant trough, we could get our yearly average rainfall in a month vs the rest of the year being bone dry. What is expected is a general warming trend but with varying extremes in fluctuation and duration. Kind of what we have recently been experiencing.

        • Chris

          Yes though it is noteworthy that the Bering sea was focal point of anomously warm water where it was in the GOA during the drought years.
          I’m thinking we might have somewhat of a repeat this year.
          I’ve noticed weather patterns tend to travel in “twos” to some extent meaning this winter will have a good dose of AR events.
          I like what I’m seeing in the ocean (which can change) where there is a steep temperature gradient in the ocean between Hawaii and the GOA.
          Some believed that was a player in the unusual storminess last winter.

          • CHeden

            Only the persistence of the “storms”, which for the most part were more ‘dirty ridges” rather than forcing from advancing L.P. and CF’s.

    • AntiochWx

      If you read Jennifer Francis’s climate work, you will have the answers to the majority of your questions. Buckle up your seatbelt, it’s just the beginning of global weirding. Once the arctic ice melts out during the summer months, the jet stream patterns are going to be ultra weak and meander like no other.

      • AntiochWx

        Also with global warming, you have the expansion of the Hadley cells, another consquence of a warming world.

        http://journals.ametsoc.org/doi/full/10.1175/JCLI-D-12-00323.1

      • CHeden

        Sea-ice melt and Hadley flow are second order cause and effects.
        In my mind, I think what I am saying is more top-level than anything I’ve read via mass-media. Until I see data that proves that temperatures and heights in the northern hemisphere have not been gradually increasing, I will continue to believe that AGW/pollution is responsible for the warming, and that the resultant increase in High Pressure both areally and in strength can be linked (either directly or indirectly) to virtually every weather phenomenon we’ve been documenting.

        • AntiochWx

          Obviously AGW is responsible for the warming, but it also responsible for the changing atmospheric changes in the jetstreams, and heights. Yes sea ice melt is second order cause and effect, but so are the changes in our jetstreams and heights. This is what happens when your climate system is retaining more heat than it otherwise would naturally.

          • jstrahl

            Bingo!

        • AntiochWx

          Honestly mass media is part of the problem in communicating the horrific affects of AGW. They are not showing the bare bones of the science that is climate change, they dumb it down to much for the average person. Honestly we need a major news network to sit down and gather a group of people from the climate science community and debate it openly on all fronts (politically and scientifically). I get so disappointed that we don’t run a permanent channel regarding all questions about Earth’s climate and its changes. If people saw the math calculations and the deep science behind the climate, maybe we wouldn’t have the issues we have today.

      • Great Winter of 2017 (SMC)

        That my explain why severe weather has been below average in the last 6 years since 2011

        • CHeden

          Quantity or Quality?

          • AntiochWx

            Quantity. Severe t-storms are fueled by greater temperature diffrentials. With a warming world, the temp gradient becomes less.

          • Great Winter of 2017 (SMC)

            Temperature differentials= lapse rates

          • CHeden

            Not along the x- axis (horizontal). Air moving laterally increases forcing, but necessarily the lapse rates. The lapse rates during much of last year’s AR events were rather low. It took orographic lift to get juicy air up high enough to precipitate out.

          • Great Winter of 2017 (SMC)

            I love oragraphic lift, gave me 10+ inches more than places 50-100 feet below me 🙂

          • CHeden

            Lift? gave you 10+ inches? Conjures up some images that I would get banned from WW if I commented any further.
            Lol!!!

          • 805 Weather (Camarillo)

            Geez, you’ve been damn spot in with your points. Great right up CHeden, & a nice shiner on the nose for people who don’t want to talk about this.

          • CHeden

            Much appreciated.
            This has been a fun thread, as I’m frequently being forced deep into my library to review pertinent details.

          • 805 Weather (Camarillo)

            Very well mannered thread as well. Glad discussions like this are going on again on the blog. It keeps the big picture in view.

          • CHeden

            Agreed. Quantity.
            But as I mentioned, when the dominant ridge(s) are favorably located, explosive development can happen…hence stronger storms when they do occur, but increasingly far and few in between.

          • Great Winter of 2017 (SMC)

            Yes, less severe weather, but more intense when it happens

          • CHeden

            Correct.

    • Great Winter of 2017 (SMC)

      Still amazes me to this day that people that I know of don’t believe in climate change even though they are getting a degree in meteorology or have a great knowledge of weather but don’t believe in climate change

      • AntiochWx

        It does boggle my mind, because all it takes to believe in AGW is the understanding of rate of changes. If you understand rate of change, you will know the current time period in our geologic history screams abnormal. I think most people do not understand paleoclimatology. The warming we have experienced since the industrial revolution is akin to running across your driveway, when the speeds we should be observing would be akin to a snail crawling across your driveway.

        • jstrahl

          And most people don’t understand the implication of “average global temperature,” a 10 deg C rise seems OK with them since they have encountered such a change after a plane ride.

          • AntiochWx

            Thankfully I think the world can be held to less than a 4C rise, terrible but hopefully enough to prevent the worst.

          • CHeden

            IMHO, a 4C increase and start selling tickets on cruise ships sailing through the northwest passage…..in December.

          • AntiochWx

            Unfortunately, it is a possibility (on the higher edge of predictions) but a possibility. It is a scarry thought that hopefully doesn’t come to fruition.

          • Sokafriend

            No, 4C would be catastrophic. 1.5 is barely a sustainable rise now.

          • AntiochWx

            It would be catastrophic, but not mass extinction for humans. We would have major societal relocations, but we would survive it. I don’t want it to even sniff this 4C, but I doubt with our current technology we would allow it to ever get above this.

          • Sokafriend

            Technology won’t allow it? We have to cut greenhouse gas emissions . That is the message we need to propagate.
            The Precautionary Principle governing risk management clearly indicates that in the absence of scientific agreement, policies should be based upon the guideline, a common sense axiom of causing no harm.
            What harm could possibly come from re orienting our policies and the ensuing messages to support and encourage the reduction of greenhouse gases? The only ones who stand to lose power and control are the ideological lunatics, anti sustainability predators, and cynics.
            And about the ‘societal relocations’ issue- the vast majority of current refugees are fleeing drought, heat, flooding that has harmed or destroyed agricultural production.
            According to a recent study out of Cornell, rising seas alone could lead to over TWO billion people being displaced within 80 years. Where would those ‘major societal relocations’ relocate to? The world would be in chaos as the process unfolds.
            http://mediarelations.cornell.edu/2017/06/23/rising-seas-could-result-in-2-billion-refugees-by-2100/

          • jstrahl

            Exactly. Lots of damage already being down, Arctic driven towards ice free conditions much earlier than worst case scenarios were predicting in 2010, even 2012.

          • jstrahl

            Well, 4 deg C will likely trigger or accentuate already-triggered positive feedback loops, the number is now over 60.

          • Bombillo1

            7 degrees Fahrenheit is a killer. Changes huge swaths of land. Water is drawn down in those areas that need it the most. Ghastly.

        • Great Winter of 2017 (SMC)

          What does the A before GW mean

          • AntiochWx

            Anthropogenic

          • Great Winter of 2017 (SMC)

            Big words that I need to understand lol

          • AntiochWx

            It’s ok, don’t worry about it. We are all here to learn, including myself 🙂

          • Chris

            Me too?

          • Pfirman

            Sometimes I read it as ‘accelerated’, before I catch myself.

    • happ [Los Angeles]

      Thanks for the info CHeden

    • Sublimesl

      Lower temp gradients, in general would point to less severe storms. The results would be less of a jet stream, and less significant low and high pressure systems, which of course are ultimately caused by cold air (and water) moving south, and warm air and water moving north.
      If all the oceans were a uniform 72 degrees all over, there just would be not much weather at all, just local convection.
      On the other hand, hotter oceans equals more energy in them, so storms could be more intense.
      I dont have the answer but I don’t think we really know for sure what the ultimate effects will be.

      • CHeden

        Depends on what level of detail you’re talking about. In several key areas, like the Arctic, I think we are seeing now the early vestiges what the ultimate effects are/will be.
        Also, just because the oceans may be warming, they are doing so because heat isn’t being released into space as a result of global subsidence…hence warmer water is just symptomatic of a lack of vertical heat (and moisture) transport.

        • AntiochWx

          The heat isn’t being released into space at the rates we were accustomed to circa pre industrialization, because CO2 ppm was lower hence having a faster rate of heat release out of our atmosphere. Our heat release is much slower today thanks to AGW.

          • CHeden

            Perhaps, but I believe CO2 is just the primer in a much larger caliber GW bullet. The real greenhouse gas is the water vapor that a warmer airmass over the oceans will hold. WV is many times more efficient than CO2 as a GHG, and is more plentiful.
            And with that being said, lest we forget the release of naturally occurring CO2 and methane from melting permafrost and melting methane ice in shallow sea’s.
            Oh, and don’t forget cow farts. Cow farts are to be avoided, too. Damn nasty stuff.

          • AntiochWx

            Yes, but CO2 is the key to unlocking all these other elements. If we reduce our CO2 emissions, we can slowly reduce the affects of AGW. The oceans will release their heat faster with less CO2 in the atmosphere and the water vapor will cool and condense with a reduction on CO2. CH4 has a shorter atmospheric lifespan thankfully, because if it had the staying power of CO2, we would be in trouble.

    • Dan the Weatherman

      Approximately what time period did you start noticing this pattern of “mega Highs” becoming more of a dominant pattern? Was it back in the 1990’s, or sometime after 2000?

      • CHeden

        Tough to nail down a specific time, but the epic drought of 1975-77 (Great Pacific Climate Shift) is when I first started noting the rapid increase and strength of Epac High Pressure systems.
        That was the transition period, IMHO.

      • mbmattcor (TD 6400′)

        Vaguely recounting it back to 2009-2010 season at least. Even the 2010-2011 season, with record snowfall in March, had a 6 week period of mega high(est) in January and February.

    • Jason Jackson Willamette

      Brilliant. For every mountain range, the higher the peaks, the more turbulent the rivers running through her valleys. The amazing things that make us wonder, leads to understanding the mystical, the music of the spheres in the wind, the rhythm of the seasons in our voyage, and witnessing the every changing turbulent universe flashing all around us.

      • CHeden

        Mind passing that around?
        I’ll go get my tie-dye on.
        LoL!
        Aside, beautifully worded. Love the imagery.

        • Jason Jackson Willamette

          It has been approved by the voters of this state. God Bless their little hearts. Go get the tie-dye, see if it still fits, LOL,

          • CHeden

            I’m positive it does.

    • Darin

      Wait, hold up. You’re dating that if we have massive high pressure, we can also have massive low pressure??!? That’s crazy talk. I jest. Are there other factors beside troposhere that contribute to persistent massive high pressures?

      • CHeden

        In Winter, the polar vortex (which originates in the stratosphere then descends into the troposphere) can be impacted…which we know can have significant Wx implications at lower latitudes when the PV significantly weakens. The displaced cold/dry air at the surface is a primary driver in re-inforcing high pressure, which we saw in dramatic form in early 2014 when most of the eastern half of NA was an icebox with overall reduced precipitation.

        • Darin

          I had once guessed that lack of Arctic ice was causal wre a weak vortex (though the science hadn’t confirmed that at the time).. Your post reminded me to look it up again and now it has been published as such. Since we aren’t seeing more Arctic ice, I’m guessing we’ll be seeing more Icemageddons a la 2014. Is that inline with what your saying in this post?

          • CHeden

            Intuitively I would agree. However,
            the PV’s last year weren’t particularly a concern despite the low ice coverage and extraordinarily warm polar temps…so I’m not bought off on any direct correlation to low sea ice and major PV events.

    • Nathan

      Thanks for the explanations and thoughts!

    • inclinejj

      Plus the 88 degree almost bathtub warm water kept making it grow and grow!

  • celo

    Great discussion tonight on GW observations and possible future.
    Thanks all

    • CHeden

      Yes, thanks to all.

  • Great Winter of 2017 (SMC)
    • CHeden

      What a bore.
      (just kidding).

      • jstrahl

        🙂

    • jstrahl

      Interesting. Unusually early for such an event. Thinking back to ’81.

  • AntiochWx

    For anyone trying to understand the natural cycles of paleoclimatology should research more into the Milankovitch cycles. For those hoping for an ice age, our current alignment and location in the Milankovitch cycle indicates it is going to be some time before we come close to experiencing that. Our orbital forcings (eccentricity, precession, and axial tilts) aren’t favorable to return to one anytime soon.

    • CHeden

      I think you mean that AGW is overwhelming the “natural” Milankovitch cycle? By rights, we should be heading into another glacial period?

      • AntiochWx

        No, AGW is overwhelming an already warm interglacial time period. The natural Milankovitch cycle responsible for glacial periods are quite a long distance away. Our current eccentricity, precession, and axial tilts do not favor a return to a glacial period for some time.

        • Hollow Scene (Riverside)

          There is a theory that global warming could weaken the Gulf Stream enough to cause dramatic climatic changes and tumble us back into an ice age through a self reinforcing effect. We already know it has weakened in the last century… Interesting to think about

          • CHeden

            IMHO, that doesn’t make sense. The Gulf Stream is thought to decline as the planet warms due to an absence of colder water flowing down from the north to sustain the gyre. However, it is also the Gulf Stream that warms Europe (and to a lesser extent Greenland) as warm water is displaced northward from the tropics. Therefore, once the Gulf Stream slows down, Europe/Greenland etc. will lose an important heat source and in turn cool down. However, and here’s where I question an ice-age outcome, is that once ice begins to reform in the North Atlantic, the Gulf Stream should resume, and Europe will warm back up..thus stopping the cool down.
            ATTM, the oceanic total heat content is so high that it would take centuries to radiate the excess heat away, and is more than enough to sustain a buffering effect on any short-period decline in global temps, thus allowing the Gulf Stream to re-establish itself long before a global ice-age evolves.

      • AntiochWx

        Well I guess technically by the years 7,000-10,000 we will have an axial tilt that is heading towards 22 degrees, so this could help establish a colder polar and increase glaciers to the north, but this is a long time away.

        • celo

          From looking at the O2 isotope data for the last interglacial period, it seems the first portion was the warmest and then is slowly cooled as the interglacial period continued. Of course, that is not happening now. But if it were, we would already be seeing quite drastic effects, such as polar ice cap expansion and global cooling. Small decreases in global temperatures can mean large consequences for habitation of more polar latitudinal area. (As we are seeing with small increases in temperature and the effects to mid latitudes). I agree in 5 to 7 thousand years the interglacial period will be ending. But as the data from the previous interglacial period seems to suggest, we should be slowly stair casing downward toward the glacial maximum. Harsher and colder winters for locations north of 30 degrees latitude would have consequences and make for the habitation less desirable.

          https://www.climate.gov/sites/default/files/PaleoTemp_EPICA_large.png

          • AntiochWx

            No arguments from me, I was merely stating a true end of the interglacial is a few thousand years away yet. You are correct in saying we should be seeing gradual long term cooling soon, but with AGW, that might be staved off for sometime.

        • CHeden

          See my new post above for some additional thoughts. You’ve made some good points.

  • AntiochWx

    Slightly off topic, but thought anyone trying to understand Earth’s climate, and movements through space would really appreciate this video.

  • Great Winter of 2017 (SMC)
  • Fairweathercactus

    Oh my ridge god on that 0z.

    • Thirstier Nick (Santa Maria)

      If it produces a heat wave much like September 1-3, please kill me.

      • Thunder98 (Santa Maria Valley)

        Likely a dry santa ana wind heat

        • Hollow Scene (Riverside)

          That first offshore event always finally feels like fall to me!

  • Thirstier Nick (Santa Maria)

    Two week forecast: 7 days ahead will be seasonable. Last week of September will be a long, brutal stretch of hot weather coming. Stock up on ice cream.

    • Dan the Weatherman

      Does this look to be a fall pattern with ridging and Santa Ana winds, or does it look like it is still a summer pattern?

    • rob b-Truckee/East Bay

      I think it’s important to remember Sept and Oct are the months the fog normally moves off the coast, Diablo/Santa Ana winds develop, and we see big swings in temps. The Oakland Hills fire was Oct 19th and how many major fires happen in So Cal early in fall. What we are seeing is a normal fall, hopefully a good sign for the upcoming winter. Temps in the Sierra and extreme Nor Cal should be dropping (as we are seeing), temps in the Bay Area don’t tend to drop until Oct15th range. So Cal follows after that.

      • Nathan

        Wasn’t Cedar Fire like Oct 25?

  • mbmattcor (TD 6400′)

    32.2° at 5 am in Tahoe Donner, first freeze is imminent

    • matthew

      31F when I rolled out of bed this morning in Glenshire.

  • inclinejj

    48.6 Pacifica,

  • Thor
  • CHeden

    Regarding last night’s invigorating discussion on GW/AGW and correlation (or lack of) to insolation changes, here’s a few additional tidbits to digest.
    IMHO, many people are underestimating the climate impacts from the natural cycle (forcing) and the departure from the natural cycle we’re talking about.
    There is both “Natural Cycle/forcing” that includes things the Milankovitch cycle(s) (there are 3 primary cycles known….Eccentricity, Obliquity and Precession/Wobble ) vs. “GHG” forcing and AGHG forcing (primarily post-industrial age (i.e. >1850).
    Within the “Natural Cycles” (Eccentricity ~ 100,000yrs, Obliquity 41,000 yrs and Precession/Wobble ~ 26,000yrs), earth spends ~80% of the time in an ice age, and only 20% in interglacial (like we are now…lucky us).
    Within the Natural cycle, and mostly since 1850, abnormally high GHG forcing has shifted global temps way outside the documented range of the Natural Cycle. Since we can discern via isotopic and molecular variation (pretty much) what is human-caused GHG (AGHG) and naturally released GHG, the data tells us that the Natural Cycle is clearly being ignored by reality, but in turn correlates well to changes in GHG concentrations that are increasingly becoming higher due to AGHG emissions (at present it is estimated that as much as 30% of GHG in the atmosphere is man-made).
    Lastly, I’d like to point out that the ratio of incoming insolar energy (~341 W/m2 at the surface or 1365 w/m2 at the top of our atmosphere) to global temperature (climate sensitivity) is ~ 0.6C change in mean global temp per one watt/m2 (at the surface) change in insolation (ignoring other factors such as corresponding changes in cloud cover, soot, etc. that affect albedo).
    Calculations confirm that based on this ratio, as much as 6C of climate forcing therefore can result from insolation changes due to the Milankovitch Cycle(s). That’s a pretty large swing..but even so, the observed resultant change in climate forcing is being dwarfed by GHG forcing.
    At present, the climate forcing from 1850 to present is about 1.6W/m2 whereas the forcing due strictly to changes in insolation is only -0.1 W/m2 (or a slightly downward/cooling trend), which is why I say the changes in climate forcing are unnatural and can only be attributed to anthropogenic causation.

    References:
    http://ossfoundation.us/projects/environment/global-warming/milankovitch-cycleswarming/milankovitch-cycles
    https://en.wikipedia.org/wiki/Milankovitch_cycles
    https://www.climate.gov/news-features/understanding-climate/climate-change-global-temperature
    http://www.realclimate.org/index.php/archives/2006/03/solar-variability-statistics-vs-physics-2nd-round/langswitch_lang/in/
    https://uploads.disquscdn.com/images/193bfb44139b1540d73576ed27595dbbd2508680b479b396e8453cbdd88b9a19.png
    https://uploads.disquscdn.com/images/55c1d92446386a33091ab1731781ffbb21e29e37e636e83539d8423346f798a1.gif

    • AntiochWx

      I’d say this is fairly spot on, I’m sure there are other forcings and feedbacks we are unaware of, but climate science has come a long ways. Just wish society would get behind the science, or at the very least if they have sceptical questions, ask them so they can be answered by top climate scientists.

      • Pfirman

        Amen, brother, amen.

    • Pfirman

      As far as I can tell, one rarely hears deniers/skeptics address isotope analysis.

      • CHeden

        Volcanic eruptions, released organic CO2, (as well as others) plus anthropogenically released/created CO2 all have unique signatures. Doesn’t take more than a mass spectrometer to measure.

        • Pfirman

          Hard science is just too hard for current leadership.

          • CHeden

            Ya, all they listen to are guys like Bob Walker and accept his “premises” as gospel.
            ie. no fundamental knowledge required.

          • jstrahl

            Nor for much of the populace. “I don’t need no science” is the big hit (to the tune of “i don’t need no doctor”)

  • Charlie B

    I have a beef about hurricane names. “Harvey” and “Irma?” Is that the best we can do in 2017??
    “Harvey?” The most famous “Harvey” is a 6’3″ imaginary rabbit. And “Irma?” The last person named “Irma” was your parent’s elementary school librarian or your great, great aunt on your mother’s side.
    “Harvey” and “Irma?” PLEASE.
    Before 1978, hurricanes were only given girl’s names. Then we started to give them boy’s names. You would think after close to 40 year’s practice we could come up with something better than “Harvey.”
    George Carlin should have been in charge of naming boy hurricanes. We would have never had “Harvey.” We would NEVER, EVER, have to deal with Hurricane “Todd” either. Or Hurricane “Kyle,” Hurricane “Blaine,” Hurricane “Cameron,” or Hurricane “Tucker.” Instead, we would have Hurricane “Nicky,” Hurricane “Vinny, Hurricane “Tony” or Hurricane “Max.” Tough names. Hard names. Names that show power and might.
    And girl hurricane names? No more “Irma’s.” No. They should be dark and mysterious. Hurricane “Crystal.” Hurricane “Jaz-Lyn.” Amber, Lola, Tawney, Roxy, Destiny, Cherry, Skye…the choices are endless. Instead we get “Irma.” We are better than that.
    Come to think of it, let’s consider labeling storms with interchangeable names. Names that fit either a boy or girl. Casey, Drew, Jessie, Jordan, Madison, Reese, Riley and Taylor are some ideas. After all, we name storms early in their life, and at that point we really don’t know which way they are going to go.

    • Pfirman

      Irma la Douce. How easily one forgets. Harvey Keitel. Enough said.
      I would love one named Bombillo, though maybe not one named Bimbo.

      • Hurricane Ol’ Saddlebags.
        Hurricane Margaret Thatcher – with that one everyone would know that’s it’s a blast of hot salty air and nobody would refuse evacuation

        • ben

          Huricane trump doesnt seem to be going anywhere, but the eye seems to continually pass over as the winds keep flip-flopping direction.

    • justsomeguy

      So the female names are all stripper names, or so I hear.

    • Admode (Susanville)

      Hurricane Stormy McStormface?

    • Thunderstorm

      My grand mothers name was Bertha. Sounds big to me. Dolly, Irma, etc my grandma would whip their butts. Hurricanes need hurricane names. Two SF Giants names come to mind both opposites, Hunter and Posey.

  • Great Winter of 2017 (SMC)

    http://weather.cod.edu/data/goes16/meso2/02/meso2_02_20170916193557.jpg TD 15 east of the Caribbean already looks like a well organized TS on satellite, this is gonna be the next Hurricane we are gonna talk about for the next couple weeks
    http://www.nhc.noaa.gov/gtwo.php?basin=atlc&fdays=2

    • Great Winter of 2017 (SMC)

      https://im3.ezgif.com/tmp/ezgif-3-53683ff5fe.gif Vis GOES 16 loop of last 15 min

    • Jim (Watsonville)

      Sure is….and the path is not looking good for the islands that were so heavily damaged…

    • Thunderstorm

      Jose has a date with the north east on Wednesday.

  • Great Winter of 2017 (SMC)

    4 differences in SST’s in the Pacific this year from last: Blob of cold water in GOA,more cold water near equator, little to no coastal upwelling, very cold water along Northern Japan and Russia ( I think). Wonder how this will affect are winter and what @cheden:disqus @WeatherWest:disqus https://uploads.disquscdn.com/images/76e3b96f755551bb1a60a487cec260db45a58058675c3a3e92691fce4e4ce033.gif and 2 Pluvious think about this. Gonna be interesting to see how everything will evolve!

    • I want more AR’s! At least colder ones.

    • CHeden

      Nice grab!
      The two years are featuring a sinusoidal wave pattern over the Pacific that are currently ~ 180 deg. out of phase with each other with decidedly different flow patterns over the west coast. However, we all remember what happened in October 2016 when a couple of bombs dropped SST’s big time, so we can’t read too much into Winter 2017 as yet based on a snapshot.
      Another thing that stands out is how well defined the ridge in the NE GoA is. In 2016, the same area was dominated by repeated troughing…which continued a Summer-long trend. This year…nothing but ridging.
      Lastly, note the increased ice cover north of the Bering Sea this year vs. last. A good sign that more cold air may be available down the road for storm development/enhancement.
      Regardless, if the pattern becomes constipated..as it sometimes does when La Nada conditions are present, the 2017 setup would not be favorable for juicy storms to sweep across the coast….rather colder, moisture starved systems dropping in from the NNW then diving down the coast.

  • matthew

    Wall Street Journal is reporting that Trump has done a 180 on Paris and that the US is now staying in the accord. Developing news.

    • AntiochWx

      Seriously? If so great news.

      • matthew

        You never know with early stories, but the WSJ is a credible news source.

    • rob b-Truckee/East Bay

      Just saw the same from CNBC, guess all the upset voters along with his family members telling him it was mistake finally got through to him. Seems the coal supporters rightly lost out to the masses and clean energy supporters.
      https://twitter.com/cnbcnow/status/909154454754164738

      • AntiochWx

        I really hope we stay in it. The US is responsible for a large portion of the AGW, and it’s very important that we take it seriously and we continue to improve on our clean energy and transportation.

    • AntiochWx

      I haven’t seen any official statements from the White House yet, I’m not going to get my hopes up until I see some statements.

    • Great!

    • Best news I’ve heard in a while, now we have a stronger chance of being a leader in a way that benefits the whole planet. Green energy will solve so many problems it’s such a no brainer that I’ve missed sleep over how we got here.

      I’m going to go take a nap of deep relief now. There is a surprising amount of smoke today in the Bay – the seasonal change will be most welcome. Anyone else experiencing headaches when it gets really heavy? A couple of people I’ve asked have had a similar feeling, like I felt yucky when I was at Crater Lake while it was on fire last month.

      It’s kind of alarming that there really is no way to escape it – looking at the shortwave IR filter it appears the smoke is coming straight down the coast from Oregon/Norcal if I’m reading this right
      http://weather.cod.edu/satrad/exper/?parms=northwest-07-24-1-100

      • Dan weather maniac (ORINDA)

        I’m not feeling much in the east bay hills. Pretty good onshore breeze here, air seems pretty clean.

        Which area are you in?

      • Great Winter of 2017 (SMC)

        you are mistakened, just some almost convective looking clouds moving over the Bay and lack of surface wind is allowing pollutants to sit and not be filtered out http://weather.cod.edu/data/goes16/swzoom/02/swzoom_02_20170916223719.jpg

        • Did you look the SW over PNW? It looks like smoke from Oregon is being pushed straight down the coast, I see the clouds you are talking about but from Oregon to the bay there appears to be dirty air flowing right down the coast. The valley I’m in right now has poorer than usual visibility, not terrible but noticeably worse. More noticeable in IR and animated.

          • Great Winter of 2017 (SMC)

            not seeing that either

    • Rusty Rails

      WH Spox already walked it back this afternoon.

      • matthew

        I saw that. Sadly, I tend to believe leaks more than I believe any statements out of the WH these days. So I hold out hope that there are some discussions going on in the background.

        • GR

          I think the free market and the developing inefficiency of fossil fuel are far more likely to bring change than any government accord.

          Meanwhile, the rate of population growth around the Western world continues to fall. When equatorial women find their way to liberation, it’ll be a global phenomenon. By the year 2117 (next century), my bet is the big worry i will be population implosion.

      • Slick

        More fake news.

    • Obama should have done more than make this an Executive office decision.

      • matthew

        Like convince Paul and Mitch to vote it into law?

  • 805 Weather (Camarillo)

    Has anybody seen the Euro 12Z? Lol

  • Great Winter of 2017 (SMC)
  • MASA: Make America $hittier Ahead
    is in full force – the 180 on the Paris Agreement is now a 360 and we are right back where we were this morning.
    I expect this next: https://uploads.disquscdn.com/images/a5c5e332b20dbfd50eba3baf7abb5b8b9a263838f6e4a9c1f14d2683cf3fe4e3.jpg

  • Thunder98 (Santa Maria Valley)
    • Eddie Garcia

      A whopping 106 to a cool 71 oh September the month of roller coaster temp swings. Storms have been a treat for most of California tho and even I got to see rain for the first time since June 12

  • Honest question. Do/can global warming models see/forecast/expect years of consecutive cooling of SST and continue to validate forecasts of longer range periods thatvteflect net warming? I hope I get ripped to shreds.

    • In a word: yes. “Internal variability” of the ocean/atmosphere system can be quite large, both in real world and in model simulations, and occasionally regional-scale cooling trends interrupt global and long-term warming.

      But there’s no such thing as “global warming models”–just atmosphere/ocean models very similar to those used for weather forecasts run for much longer periods of time and ultimately analyzed using different metrics and under different assumptions.

  • jstrahl

    Just coming in for a check. It was strange up in the Berkeley Hills today (Tilden, Seaview Trail). Felt warm, but a definite cool touch. Looked incredibly dirty and hazy towards the Bay, had a hard time seeing the Gate (!) and SF skyline. But looking around me or up/down the hills it seemed quite clear. It was strange, and it wasn’t JUST my state of mind. 🙂 Strange energy.