Break in storms comes to end; Northern California closes in on record wet season

Filed in Uncategorized by on March 18, 2017 2,491 Comments

Multi-week break in active storm pattern allows water to recede

A persistent trough along the West Coast–associated with wet conditions in California–has co-occurred with a persistent upstream ridge over the Aleutians. (NCEP via ESRL)

2016-2017 turned out to be quite the winter across California (especially in the northern half of the state). A relentless series of storms–driven by persistent troughing and an associated active jet stream along the West Coast–brought numerous atmospheric rivers and associated heavy precipitation to much of the state since November. Notably, there was in fact a broad and highly persistent downstream ridge centered over the Aleutian Islands for much of the winter. This conspicuous feature does bear some resemblance to the Ridiculously Resilient Ridge which plagued California in recent drought years, though clearly its position this winter was far enough west to have vastly different effects in the Golden State. I will eventually have a more comprehensive post focused on the possible causes of California’s reversal in fortune this year, along with some thoughts regarding why such an anomalously wet winter was essentially unanticipated.

All of California has been wetter than average this winter; most of Northern California has experienced record wet conditions. (WRCC)

On average, California has experienced near to above-average temperatures this winter, despite consistent precipitation. (WRCC)

Interestingly, none of the individual storms so far this season have been particularly destructive by California’s historical standards. Instead, most of the widespread flooding, mudslides, and other infrastructure disruptions that have occurred stemmed primarily from the cumulative effect of unusually frequent moderate to strong storm events. It has been previously noted that California’s most dangerous flood events do not necessarily occur during California’s wettest winters, although it’s not totally clear whether that’s just a matter of historical luck. What is pretty clear, though, is that this year’s extreme wetness on the seasonal scale has pushed parts of California’s aging water infrastructure to the brink–and had even a single additional warm, wet atmospheric river come ashore during the peak of winter, the overall flood situation might have been considerably more serious.

Fortunately, most of California did receive a substantial break from the wet weather over the past couple of weeks, with mostly dry and warm conditions nearly statewide so far in March. That dry pattern, however, is rapidly coming to an end (as I discuss further below).

 

 

 

Yes, California really is closing in on wettest Water Year on record

Now that we’re more than 2/3 of the way through California’s wet season, it’s pretty clear that much of the state has experienced its wettest 3-6 month period on record. Virtually every corner of the state is above average to date, though anomalies have been much more impressive in the north. The Northern Sierra watersheds are currently sitting at just above 200% of average precipitation for the season to date–a rather extraordinary statistic. If California receives at least average precipitation for the rest of the season, 2016-2017 would become the state’s wettest Water Year on record.

Overall, California’s year-to-date precipitation is nearly the wettest on record. (UCSD)

Snowpack in California’s mountains is also well above average and the highest since the very wet/snowy winter of 2010-2011. What is striking, however, is how much Sierra snow water equivalent has lagged overall precipitation. For example, Northern Sierra snow water equivalent is currently 145% of average (vs 202% of average for overall precipitation). This effect has been particularly pronounced at middle-elevation regions where wintertime temperatures are more “marginal” for frozen precipitation than at colder, higher elevations. While this winter has certainly been colder than recent (record warm) ones, conditions have still been near to above average across most of the state–and more importantly, have been considerably warmer than during most of California’s historically wet winters.

 

Substantial late-season storminess to return; Central Valley thunderstorms likely

Model ensemble forecasts suggest a high likelihood of moderate to heavy precipitation over Norcal next 10d, with light to moderate amounts across SoCal. (NCEP via tropicaltidbits.com)

California’s temporary reprieve from wet conditions is rapidly coming to a close. A series of storms will bring renewed precipitation to most of the state over the next few days, and accumulations could be pretty impressive for mid-March. Northern California is expected to receive the lion’s share of precipitation from this series of storms, but Southern California will definitely still see some rainfall (and perhaps some heavier stuff, depending on how the details work out). Several of these storms will have a respectable moisture tap, and heavy precipitation may occur in the same orographically favored areas that have already seen a tremendous amount of rain this winter. While none of these storms looks especially strong at the moment, soils are still saturated and rivers running high across the northern half of the state. Thus, there will probably be some renewed flooding concerns at some point over the next 10 days, especially since any rainfall will combine with the early snowmelt pulse that has already begun this year. Also, since these storms will be relatively slow moving and will likely contain substantial moisture, there is the potential for precipitation accumulations to end up somewhat higher than are currently anticipated.

 

The upcoming storms will also be associated with cold air aloft during at least a portion of the event, and with the increasingly strong March sun angle atmospheric instability will be elevated across much of the state. Thus, occasional thunderstorms are a good bet across favored areas (especially the Central Valley and perhaps parts of the South Coast). Some locally strong to severe thunderstorms will probably occur at some point over the next 10 days in the Central Valley (as often happens in March), but pinpointing the most active days is difficult at the moment. Needless to say…an active late winter/early spring weather pattern will likely be in place for at least the next 10-12 days, and perhaps beyond.

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  • Eben

    https://uploads.disquscdn.com/images/b9b8584227612caff4181d479b9d5149776fc15f2dce9b9d67aaa4670eb68c6b.png

    March is done, and we’re up to 61.83″ of rain for the season in Stevens Canyon, near Cupertino, edging out 2005-06 for a new record since I moved here in 2000. Any more rain and I’ll have to enlarge the y-axis on the chart!

    March came in at 5.12″, within 0.01″ of the 15-year average, so things dried out nicely after the deluges in January (21.42″) and February (19.22″) which left a foot of mud on my driveway and everything soggy.

    An epic winter, though looking at the 80-year data set from the Stevens Creek Reservoir rain gauge, still 50% below the wettest year, 1982-83. All things considered, this amount of rain was enough for me!

    • That’s an awesome graph!!! Did you make it yourself?

      • Eben

        I made it with Excel. It’s not ideal from a day-to-day standpoint, especially when I decide to tweak things. I keep meaning to find a charting program to automate the process, but I haven’t yet found the time to do that. I originally started keeping track of rainfall on a sheet of paper, but after a few years moved to Excel. Someday it will be in a database so I can do all sorts of analyses.

        • One more Q where did you get data from? SCvalley Water? If so how? I’d like to do one for my area closest to me in Morgan Hill

          • Eben

            Start at the water district website:

            http://alert.valleywater.org

            They have a list of precipitation gauges here, so you can find the one closest to you:

  • 805 Weather (Camarillo)

    For the early birds this morning, the tune of the 00Z Euro was trending slightly wetter and further south. GFS is still pretty shaky on handling this, but in some cases getting a bit better to see what’s going on, so I’ll make my points below. Waiting on 12Z GFS now. Graphics below consist of 00Z Euro & 06Z GFS. https://uploads.disquscdn.com/images/dec4d5c6f5d9285797e747ee944f19874a7915c806148b8dd57e357b6dcde705.gif https://uploads.disquscdn.com/images/6d6a372769fe210ff83e9f3750dd0da481009d5d56e8ec9bc2c6ffb8d7b5ac6d.gif The pattern is similar to what we saw back in week 3 of February, however several things are at play here that change how this scenario will unfold like that cycle.

    1. Convection. & Oh boy, will it be favorable. https://uploads.disquscdn.com/images/972aa9dc9f9dda4ea8bf0f7d4d72dbfd90e9ff7bae72cd7c9c12a7c2c461d231.gif https://uploads.disquscdn.com/images/82194f999c4bac5f99f515b0172a31fa363b97d76b071f8b9825d0e78715f562.gif *

    •For K-Index reference* https://uploads.disquscdn.com/images/3b531b3612e45022b37f06c3e362420e3ab1e6745ecc2fd691bec916da2b0622.png

    2. A strengthened jet *across the state* with each system
    700mb hPa Wind Speed Euro & GFS
    https://uploads.disquscdn.com/images/76adb98c1d7fb11d543c2a29bafd3f8493a1cafd76c899d0a70a717ccbae83fd.png
    https://uploads.disquscdn.com/images/ee615674d571e0fdcf63818b15bc6bb1ada47008d88f49aac1dc1b8bdccf0454.png

    3. Cold air advection.
    https://uploads.disquscdn.com/images/9395cdb041f01db794775f16a27316520055651610a239ef048ec42040a830b7.png
    https://uploads.disquscdn.com/images/bdb7b58584edcb62f407d62f00dfaa322f94ae3737bff3a55546da3147ac413e.png https://uploads.disquscdn.com/images/ae3424b11b5aba456dd4304ff3cc85c0f2531cf596d8c21c1df24ec74e261862.gif https://uploads.disquscdn.com/images/10d53b5732f7c0dc29f90a5e6c48da6256c7e4e8b2f9efb161e5b04592160553.gif

    4. Even higher sun angle for increased surface heating.

    • weathergeek100

      Excellent graphics. Thank you. I’m heading to SoCal this weekend. Hope to see some rain down there.

      • 805 Weather (Camarillo)

        The last two are my favorite, they really show the fluidity and the temperature gradients very well.

        • Yolo Hoe

          Great tip — I just spent more time staring at them — thanks again for a great post!

      • Dan the Weatherman

        I’m looking forward to some late season rain down here as well.

    • The GFS spaghetti’s are very close together at different DAM and suggest a decent wind event for the northern half of CA on Friday

    • jstrahl

      Thanks very much for this detailed post. Jet stream charts seem to show a an aim right at the Bay Area.

    • Jason Jackson Willamette

      Excellent stuff 805. Very professional and informative, great post. Can’t wait for the “stuff” to roll into the Bay area and beyond. Am a bit worried however, about a lot of rain in the Sierra’s.

      • 805 Weather (Camarillo)

        Thank you, I’ll be keeping on my toes until this whole thing winds down as usual.

    • Bobby M ( San Carlos/Tahoe)

      Besides K-Index is CAPE near 1,000?

      • 805 Weather (Camarillo)

        Generally speaking it would average anywhere through this cycle 400-800 jk/g max 1,000 jk/g more towards the Sac Valley. I do think if you are NorCal chaser this pattern will be greatly appreciated.

  • 805 Weather (Camarillo)

    From someone I follow, neat link attached showing debris in the canyon. https://twitter.com/GaryValle/status/848898902921142273

    • Nathan

      Interesting (but unsurprising) stuff on the dying redwoods in Malibu Creek State Park.

      There’s a big grove of them down here in Balboa Park; I’d say 60-70% are gone as of this past year. To the survivors go the spoils…

      • 805 Weather (Camarillo)

        Yep, it seems the last of them this far south are hanging on by a thread.

        • Nathan

          There’s one in my friend’s neighborhood in LA that’s hilariously resilient – cut off at 25′ to avoid powerlines, two scrawny branches, mostly just buds straight from the trunk, in the full sun, on a busy LA intersection – and yet….it endures. The world’s toughest redwood. It’s budding with new growth this year.

          • 805 Weather (Camarillo)

            Honestly there is a handful of them in some of the richer neighborhoods, those that do still survive thrive pretty well too. Almost like a super species of the coastal redwood or something.

          • alane777 .

            Are these in Venice ? A friend took some seedlings from us years ago and planted them years ago in venice. I later heard they grew so big and fast he had to cut them down. Generally when you cut a redwood several will then grow from the stump. This is why timber companies do not have to reforest redwoods.

          • Rio Rat

            Somebody in the right department should put that redwood out of its misery.

      • happ [Los Angeles]

        I rarely see redwoods in SoCal. Is it a matter of not enough rainfall and aridity?

        • inclinejj

          I have seen a few around Incline Village. North Shore Lake Tahoe.

          • giganteum or sempervirens?

          • inclinejj

            I don’t know, I can snap a couple photos when we are up for Spring Break/Easter Week.

          • Dan the Weatherman

            The trees in Incline Village are likely Giant Sequoia (Sequioiadendron giganteum) rather than Sequoia sempervirens (Coast Redwood). The coast redwoods generally need a milder maritime climate to grow and the mountain climate of the Tahoe region is likely too cold.

          • inclinejj

            Thanks. Is that the same Sequoia that thrives along the coast?

          • Dan the Weatherman

            Sequioia sempervirens (Coast Redwood) is the one that thrives along the coast, while the Giant Sequoia thrives in the higher mountain regions.

        • Dan the Weatherman

          They tend to not do well in hot dry areas. They like a cool moist maritime climate like their native habitat in coastal northern CA. They likely do better in the milder coastal areas of Socal with a good deal of water as opposed to areas more inland such as Riverside or San Bernardino.

    • inclinejj

      An article and cool You Tube video about the Malibu Creek and Lagoon Steelhead Trout.

      http://www.laweekly.com/news/is-the-first-steelhead-trout-in-decades-really-back-at-malibu-lagoon-4757393

    • Jason Jackson Willamette

      I know it’s entirely weather geeko-rama stuff to save these images, but these were captured on that 2-17-17 event that caused all that flooding in the LA area. An amazing amount of rain fell during that 48 hour period.

      https://uploads.disquscdn.com/images/7ebfe1593b00c88d839bf40f4a1a267fcb12c1778e1016898fd680d9a47ed81f.jpg https://uploads.disquscdn.com/images/686cdd3d8632bace5e63c485ddfe01717bea66bf2688cf27b66acd373b9db804.jpg

      • 805 Weather (Camarillo)

        I wish I didn’t have to hunker down so much in that system so that I could see the actual intensity. It was a great show though!

  • Nate

    Keeping in mind that this is a single op run, the 12z GFS shifts the focus of the AR south to the Santa Lucias and southern Sierra. Even though this will probably change, it’s still something to keep an eye on.

    https://uploads.disquscdn.com/images/6add4bff5049f0625e161ff665bf9911cf36102843f199421c9b33d119e66805.png https://uploads.disquscdn.com/images/a37a38f7602f7d28136ec6ee0b034887dbd2217e1542b65c9d532e542ac0cd8f.png

  • inclinejj
    • 805 Weather (Camarillo)

      Yikes, that’s new to my ears!

    • Craig Matthews

      This is incredible for this time of year, or any time of year for that matter.

  • inclinejj

    Message from Howard Mammoth Mountain.,

    Friday evening update:

    First off, Howard has decided to open up the Weather Letter to anyone who would like to sign up. No credit card, no payment, no strings. You will receive the Weather Letter twice a week on Thursday and Monday in the early a.m. The only catch is the letter will end on April 27th, 2017. From the 27th forward, all the reports will be found on Howard’s web site – http://www.mammothweather.com

    • rob b-Truckee/East Bay

      His letter was being posted on Opensnow.com/mammoth as well. Not sure if that’s the reason maybe he decided to just open it up to all who wanted it.

      • inclinejj

        I am assuming(and we all know what happens when you assume) that the paid subscriber counts probably were not worth continuing.

  • happ [Los Angeles]

    Stratus clearing now. April starts the season of morning coastal clouds. I’d rather have stratocumulus clouds with rain showers. Maybe later in the week, I hope!

    • Dan the Weatherman

      There’s a chance of rain on Friday. I hope it verifies!

      • happ [Los Angeles]

        Right now models are showing significant rainfall for much of California though iffy south of Pt Conception, as usual

  • Jason Jackson Willamette

    Dang! I’m going to have to empty out the orange and apple blossom petals from my Lowe’s rain gauge/tube before this return of wet weather.

    From the NWS MTR office.

    “On Thursday a substantial change in the pattern will take place as
    a longwave trough advances to the coast and an area of low
    pressure deepens and moves to the PacNW. An associated cold front
    will spread moisture to our CWA starting late Thursday or early
    Friday. Rainfall could be moderate to heavy at times especially
    along the coast and in the North Bay. Rain will switch to showers
    behind the front later in the day and continue into Saturday. Rain
    amounts are forecast to be 2 to 4″ for the North Bay and coastal
    ranges while other locations will generally be between 3/4″ to 2″.
    IVT forecast shows the potential for values to possibly exceed 750
    kg/m/s suggesting rainfall amounts could be considerably higher. Winds
    will be the other story with gusty southwesterly conditions
    likely. 925 MB speeds are forecast to be up to 50 KT on Friday —
    a wind advisory will likely be issued.

    On Sunday will transition back to drier conditions as a weak ridge
    builds back into our region. Longer range guidance suggests more
    rain could return by the middle of next week.”

    https://uploads.disquscdn.com/images/c653b8a7ad0d977914511215ba9697343aa88069f95ee035c1f23c12c1075279.jpg

  • happ [Los Angeles]
    • rob b-Truckee/East Bay

      I will say it’s bee a treat to fly over California and see everything so green from north to south. Love it!

  • AlTahoe

    The 12z shows a 528 cold low sliding right over the Bay Area next Monday. That would be a good setup for Thunderstorms region wide. It will be interesting to see where it ends up wobbling around to on future runs.

    • Bobby M ( San Carlos/Tahoe)

      Doesn’t matter what forecasts say about thunderstorms, they don’t happen here

      • 82/83 El Nino Baby (San Jose)

        Agreed. Only thunderstorms we get in San Jose are the random monsoon (see pics below from 2015), or in the post front convective showers. It is thee convective showers that have been lacking from most storms this year. Probably due to so many ARs versus GOA storms.

        When I was a kid, electrical storms seemed more common. I recall a few nights where it was hours of the sky being lit up, but no rain came with it.

        https://uploads.disquscdn.com/images/4ac0f3088e98f5a6c452bad651d6bb292f9b1c5f20db614e5363ef60756476d5.jpg

        This is a few hours before the lightining started.
        https://uploads.disquscdn.com/images/564b92784c6d8d3d04956d9b2528badf7681013b6339aeee3a234ae7a00c70ae.jpg

        • AlTahoe

          San Jose’s best setup for Thunderstorms is the exact setup I mentioned above, which is a cold upper level low (popcorn clouds) moving right over the bay area in late spring. If it were to verify as shown, there would be thunderstorms in all parts of the bay area. In the 2000’s when I lived in San Jose (by the airport) we would usually get one or so a year. Some years would have multiple cold upper lows with lot’s of thunder storms. spring of 2011 featured multiple thunder storm days.

          • Bobby M ( San Carlos/Tahoe)

            Thunderstorms have been forecasted here 20 times or more this year and thats not an exaggeration, every storm pretty much

    • Craig Matthews

      If those 1000-500mb heights and thickness verify, and the Low does not get pushed into inside slider mode on us, the coast range could receive a late season snow. April 2003 is a standout where I remember some cold and very wet Lows moving thru the entire state, kinda like what is being shown by some of the models right now. We had 6″ of snow on Anderson Peak, which is around 3700ft above Big Sur. And in April 2011, we had a couple of similar events where we had snow blanket the Santa Lucias, and tornadoes in the Central Valley when the cold cores moved inland.

  • scott

    The wife and I were supposed to spend Saturday and Sunday in Mammoth Lakes for our anniversary. I am glad I didn’t book the hotel yet because NWS Reno is sounding serious about this weekend….

    “for what is shaping up to be a potentially major storm next weekend”

    “Confidence continues to increase in what looks to be a moderate atmospheric river (AR) event the weekend of April 7-9.”

    “Gusts up to 60 mph are likely to cause problems with travel for high profile vehicles in addition to turbulence, wind shear, and mountain wave activity for aviation; and choppy conditions on area lakes. ”

    “While this storm is nothing like the huge AR events we saw in January and February, it has the potential to be a significant snow event for the high Sierra, with several feet of snow likely.”

    “Major travel impacts are likely across all passes beginning Friday lasting through much of the weekend. ”

    Here comes the real kicker….

    “Also, if you have travel plans next weekend, it may be best to either get out
    ahead of the storm, or wait until it is over. ”

    They are talking about snow down to the valley floor by Friday night. So I can see any commutes on 395 and the 203 will be very slow and tedious at best.

    I have decided to wait until the following weekend to hit Mammoth. The truth is…..I must go on a Saturday because Slocum’s has the best prime rib on the entire planet, but only on Saturday nights. 🙂

    • Crouching Dallas

      Not sure how you read this: “While this storm is nothing like the huge AR events we saw in January and February, it has the potential to be a significant snow event for the high Sierra, with several feet of snow likely.”

      And come to this conclusion: “I have decided to wait until the following weekend to hit Mammoth.”

      Think of the gnar, Scott! Weren’t you up there a couple weekends ago, when that storm split favorably for Mammoth? Good times. That Saturday was excellent riding on the hill, even grabbed a couple fresh runs off 23 when the top popped.

      • scott

        I would love to be in it and that Friday was awesome! Even cross country skiing in town on the trails as excellent! Though my wife is a Southern California girl with a broken back and I worry more about her safety than my own and for our anniversary I promised to stay with her and not go off skiing. This way I get brownie points to ditch the family a few more times for April and May. Its a strange thing because I will risk life and limb to do crazy stuff and yet if my family is with me in the car I become grandpa behind the wheel.

      • Aloha12

        Was up there this weekend (yesterday and Saturday). I’m usually always planning around storms for the fresh but this weekend had me reconsidering what I like best. Nothing wrong with mid upper 40’s, no wind, soft corn snow. Just ski mid and upper mountain and stay away from Eagle (too low). Fun!

    • inclinejj

      Keep in mind school is out for Easter Week/Spring Break. Have a Mammoth Brewing Company beer for me!

      Slocum’s is as good as the legendary House OF Prime Rib in San Francisco.

    • PRCountyNative

      It will be great! Travel hassles aren’t required.

      The linear water vapor marks the spot!

      https://uploads.disquscdn.com/images/1fa0da02dd248615a24c0c92f3936ff99427b8a08de38a880ec937e07c164a93.jpg

  • Given that forecasts are tending toward a powerful late-season (April!!) atmospheric river across northern/central California late this week, I’ll probably have a blog update Tuesday or Wednesday.

    • Dan the Weatherman

      I hope Socal gets in on the act on this one as well. The late March storms were forecast to bring some decent rains to Socal, but they fizzled out before they got here and March turned out to be really dry down here.

      • 82/83 El Nino Baby (San Jose)

        Looking forward to your update. In your update, can you compare this AR to others this year? I am curious how the dynamics look. Some ARs this year have been fruitful regardless of microclimate, where as others have left some areas high and dry (mainly valleys). I would think that with the later time of year (more sun) combined with the abundance of moisture would help with dynamics/convectivity.

    • Crouching Dallas

      Crank up the hype-machine, Daniel! 12Z GFS or (literally) bust!

      Also, on an unrelated note, you’ve got a strikingly similar doppelganger somewhere in LA, and he sometimes skis Mt. Baldy.

      Saw said imposter on the slopes a few weeks ago. The following dialogue ensued:

      CD: “Sorry if this is super random, but are you by chance Daniel Swain?”
      Not Daniel Swain: “I’m not, unfortunately.”
      CD: “Haha, well that’s awkward. For the record, he’s a prominent climate scientist and is spearheading drought research.”
      Not Daniel Swain: “Oh wow – I will gladly take that.”

      And with that he skied away, down the face of Thunder Mtn, leaving me with my buddies, now mocking me for reaching peak nerdiness.

      • Pfirman

        Well, you were on a peak.

  • mattzweck

    Been typical spring here in the high desert Lancaster area. Windy then calm other half the week. And in 70s to 80s.

  • happ [Los Angeles]
    • Craig Matthews

      Its beautiful out there right now, and the bloom has yet to max out with all the colors. Lot of flowers yet to bloom. If this late week storm verifies, it would be ideal. A good ride is from HWY 46, down the Cholame hills route along the San Andres Fault to Carrizo Plain, then down New Cuyama…down up down and over until ya hit I-5 near Frazier Park.

    • at least give credit to the photographer

    • max

      Beautiful. Which route did you take to get up.there? Roads OK?

    • happ [Los Angeles]

      Craig Matthews from Big Sur took this and many more beautiful photos of Monterey County

      https://twitter.com/craigmatthews48

      • Craig Matthews

        Thanks 😉

  • Craig Matthews

    Big Swells along the coast today and a lot of salt in the air….signs of an active NPac. My windshield is a mix of salt and pollen….yuck!!

  • Craig Matthews
    • Crazy good stuff. You need to put those in a bottle and sell them.

      • Craig Matthews

        Thanks. This is a really good opportunity to get out there and enjoy this super bloom. And it’s super…for sure!! I think next week or the week after will be the peak as far as color variety. The Ranger said mid April.

    • scott

      Awesome!

  • Jason Jackson Willamette

    Wow,,, it’s going to be interesting to say the least watching this system for later in the week take shape to our west. Just by judging from this latest snapshot, I’d say the stage is being set –

    https://uploads.disquscdn.com/images/9d70706ce23afabad9afe8080acb191ae81866045acd4c3d860fe3acd584a684.jpg

  • Tyler Price (Monterey/Seaside)

    I hope everyone is ready for an awesome April!! That storm slated to hit the west coast and slam into California next week is looking more and more impressive with each successive run now per the GFS!! Jet stream level winds are strong upstream behind the deep trough.. they push all the way into California and the lowest point of pressure in the storm is quite impressive for April dipping into the 970mb range! Speaking of dipping that weather bomb sure does take a deep dip down the west coast for April! Really looking forward to this late season AR storm set to hit California next week! With the higher sun angle and the colder air aloft moving in behind the low I would expect convective elements with this storm system! Maybe even in the cold front itself and not just behind it because of the good jet dynamics and because it’s April and there will be better surface heating!! https://uploads.disquscdn.com/images/6b13cd0e79924a5a66ca2258256b03e3157ec0e1d06c6076def3a70794a62d9b.png https://uploads.disquscdn.com/images/67758ec70d5637744dd9e19b791efa6fa0c5734f81701e956072b3e1a0019003.png https://uploads.disquscdn.com/images/9517db310abe93eb4d54fcddf745431032462de85397a73039033a6c61608210.png https://uploads.disquscdn.com/images/913cbe1e25a979ed04159502d55bc606bda37fb86f280283bda0e71a729e08c1.png

    • 82/83 El Nino Baby (San Jose)

      Too early to say, but is there any storm/AR from earlier this year that we can compare the upcoming event to?

      • Tyler Price (Monterey/Seaside)

        Looks similar to the January storm train the first one that hit in January IMO.. with the placement of the Siberian ridge and the way the jetstream is coming in looks very similar.. if I’m remembering correctly

    • Rusty Rails

      I’m assuming you mean later this week. It’s Monday.

      • Tyler Price (Monterey/Seaside)

        Yes sorry I edited it.. my bad I stand corrected I’m use to working Mondays, but have today off so it still feels like the weekend for me lol.. totally forgot it’s Monday ?

        • Rusty Rails

          No worries. I just figured you would want to edit that for clarity.

  • 82/83 El Nino Baby (San Jose)

    Here is a Map showing the recent Peru rainfall totals compared to the very wet years of 82/83 and 97/98. It would be cool to see a map similar to this, but for CA this year.

    https://uploads.disquscdn.com/images/d9dcc68aa1cd16eada9c2c4a28d7f702bd87ae8b33072ae20db813517819f35e.jpg

    • AlTahoe

      Are these anomalies in the spring time the year before an El Nino? Like March 1982, 1997 ect?

      • 82/83 El Nino Baby (San Jose)

        That is how I read it.

      • Charlie B

        Is this year the analog to 1981-82 that would have broken many records were it not for a snowless February as a prelude to the El Niño 1982-83 year?

      • Yanet Garcia (NYC, USA)

        EFM
        Enero
        Febrero
        Marzo

    • Jason

      Is there a map that shows the absolute amount of precipitation – as opposed to the percentage change – along the Peru coast? Typically, Lima and other coastal cities get only 2 inches of precipitation per year.

  • Fairweathercactus

    I recall that Downtown LA on Average gets its last storm of the season on average April 20th and first storm is October 10th. So we are getting around that time of year where 1-2 more storms is likely.

    Also May has been very active for the most part the pats 10 years or so.

    • DelMarSD

      Last sentence is very true.

    • RunningSprings6250

      One last hooraw on 4/20 eh? I’m there!

      • Pfirman

        Really? Your last? Sad that.

    • Dan the Weatherman

      I wouldn’t mind a May 2015 repeat.

  • Bobby M ( San Carlos/Tahoe)

    For my location compared to Golden Gate Weather’s total’s for San Francisco since 1849, were having the sixth wettest winter ever and will likely end at the third wettest winter ever with this next storm likely dropping 2-3 inches on me! Current Rainfall: 37.1, need 1.8 more to become third wettest winter ever to beat 3 seasons with 38-38.9 inches of rain. So basically this is a 1 and every 50 rainy season for my location. Interesting to note, San Francisco’s rain this year rain is about 8 inches below mine at 29.38 inches, anyone know why?

    • inclinejj

      Your closer to 101 than 280 right?

      • Bobby M ( San Carlos/Tahoe)

        Yes

    • DelMarSD

      Huge variations in percip due to micro-climates in the Bay Area. We have that here as well, but nowhere near the level you guys have it up there. A couple hundred feet or a few miles south can make a massive difference in rainfall.

  • scott

    This is peak time for orange blossoms. The smells are amazing around the Central Valley. It’s worth it to find a grove nearby, park, and take in the smells

    • happ [Los Angeles]

      My orange tree was in flower a few weeks ago; the beautiful scent was almost too strong. I can’t imagine what an entire orange grove would smell like.

      • Dan the Weatherman

        My mock orange shrubs (Pittosporum tobira) are in bloom right now and the scent is in half of my backyard. They smell similar to orange blossoms (reason they are called “mock orange”).

  • Utrex

    Sacramento is looking very green atm! When looking at trees you can see the inner parts are all dried up and the rest of the tree blowing up with green color.

  • AlTahoe

    We are having one of the wettest seasons ever here in South Lake Tahoe with just an average snowfall season. Usually the wettest winters are also the snowiest. The plus side is that I was able to disc golf after work today on the bijou front 9. https://uploads.disquscdn.com/images/b86eb52f7a0d35a146c2a5e6a80c5d06f3efe038da83b6a05a892a83cfd6815b.jpg

    • Dan weather maniac

      I know that area well! I used to skateboard at the SLT skatepark in my younger days when I lived in Tahoe.

      Now that I think about it…. there was more snow then, than now, this time of year. I know because I waited patiently day by day in the spring for the skatepark to fully clear of snow and it wasn’t until later in April.

      This was 98-99 the year after the epic El Niño. Still a great snow year if memory serves correct, but nothing like this year in terms of total precip.

      Also I recall my yard on the shady side of the sun along pioneer trail in SLT near the casinos being buried under 2-4ft pretty much all winter.

      • AlTahoe

        I don’t think I could even disc golf at this same time last season. The previous 3 winters you could play pretty much all winter. 6200′ in the Sierra now days isn’t like the 6200′ pre 2010-2011
        Also there were lots of kids at the skate park today

        • DelMarSD

          What’s your percip total for the season?

          • AlTahoe

            44″ or so + or – 4″

          • Dan weather maniac

            Wow that’s total water? Orinda at elevated 600ft might have you beat. That’s surprising.

          • DelMarSD

            Yeah I thought it would a be a lot higher.

  • Martin Pettet

    How about a prize for the best imitation Gene Kelly “Singin in the Rain” video from the next storm.

  • happ [Los Angeles]
  • Crouching Dallas

    00Z GFS looking like it’s gotten into daddy’s moonshine, plus some bathroom crank on the side. Still a ways out, but anything along those progged lines would be a bonanza for high elevation Southern Sierra.

  • tomocean

    For Daniel. Just got the malware ad that popped up on my android tablet. Attached a screen shot.

    https://uploads.disquscdn.com/images/98eae8f9408e4e9e079028afb81ab445a585785717bd0f81e0265ea63d5d5e9e.png

    • Tazmanian

      in stall ad block and you will not have any more issue with ads on here i will not used this site with out haveing a ad blocker on here too block the ads

      • tomocean

        I want to support Daniel and the blog with ad revenue. Most of the ads are non-intrusive. This one being the exception.

        • PRCountyNative

          Click on them occasionally to support Daniel, block them routinely out of self respect.

      • inclinejj

        After installing ad block you can go into the settings and select which sites you wish to see ads from. Mine wouldn’t let me see or run forecast maps and attachments on this site and Bryan’s site.

        I down loaded mine from google apps.

    • Thanks–this is apparently an internet-wide issue, and has become a problem on major sites that have ads served by Google Adsense.

      It is very hard for me to do anything about this kind of disruptive ad (short of shutting off all advertising) as I have yet to encounter a single one on my end, and the culprits are being quite sneaky regarding the original source. If you are willing, I would strongly advise you (or others) experiencing the issue to fill out this Google form to report the ad:
      https://support.google.com/adwords/troubleshooter/4578507?hl=en

      or, if you’re willing to spend bit more effort, you can find the ad tracking URL as described here:
      https://support.google.com/adsense/answer/3382225?hl=en&ref_topic=23390

      and send it to me via email.

      I’m continuing to work with Google to try and resolve this issue.

      In the long run, I am exploring other options that would allow for a better site experience.

      Thanks again for your patience!

  • Nathan

    Reports of flooding…

    …in my house, because a f@#$ing inlet hose burst.

    I can sleep in it again “in 5-7 days”.

    @#$#@^@%$#@%@#

    • Pfirman

      I had a flood issue and vowed never to include the insurance company again after their hired goons supposedly found asbestos in sheetrock and made me a stranger in my own house.

      • Nathan

        they’re doing asbestos testing today. I know the unit was built after asbestos was generally outlawed, so if they find it I know it’s basically a racket.

        • Pfirman

          Racket. Mine was from two different remodel events, both after the outlaw. They had some story about ‘imported’ sheetrock. The men in white suits basically did demolition. When the ServPro guy said he had to jackhammer a marble tile floor upstairs I kicked them out of the house for good.
          Next time I just hire a contractor and screw the insurance, which also was a joke.

  • ECMWF Ensemble keeps the storm door open for the next 14 days.

  • ConcepcionImmaculadaPantalones

    Meh, I should move North to the land of much cloud cover year round, SoCal and its incessantly sunny nonsense has never been my thing. 😛 As long as I don’t reveal where I’m relocating from (born and raised western sorta-coastal OC/LA) the PACNW will accept me right? I remember the joys of cool and overcast days during summers visiting family up in Vancouver WA across the river from Portland as a kid and it was awesome.

    • PRCountyNative

      I did that, got there, the transplants had the locals outnumbered. No problem.

      • If I were a local I might not like that

        • PRCountyNative

          Ask a native american how they feel.

  • CHeden

    Calm, 52F and partly cloudy this morning in Cottonwood. The cloudiness is from Pacific air aloft in the wake of yesterday’s dry front, so the atmosphere is already starting to juice up.
    A quick roundup of the area’s AFD’s show quite a few discrepancies and ‘caveats” in their discussion for the Friday-Sun event. A few highlights include Eureka talking about the low on Friday being a vertically stacked low, while LA/Oxnard describes it as just an upper low; then the Monterey AFD comments about whether or not the Santa Lucia’s and points east (towards Mammoth) will get hit with an AR (GFS-wet, EC drier). Then, LA/Oxnard flat out refuses to guess how much of a subtropical feed will impact the Southland, especially south of SLO, with the GFS showing 5x the precip totals than the EC. Reno also is commenting on quite a bit of uncertainties in snow levels and precip amounts..once again mentioning if/how much subtropical air moves in, and therefore raise snow levels while also increasing precip totals.
    Then, there is my comment that the Friday low will likely be undergoing rapid intensification as it nears the NW Calif. coast, which we all know is extremely difficult to forecast even 12-24 hrs. out.
    So anyway, for us geeks it’s time to speculate to our heart’s content as to the actual precip totals through Monday since there isn’t anything close to a consensus forecast-wise to work from. Up here in Cottonwood, I don’t expect any big rains since rainshadowing should be quite efficient….however once colder air works in, we could be seeing some convective activity on Friday (post-frontal) and again on Saturday.

    • GFS seems to bring these systems in a little earlier?

      • CHeden

        Yes, you are correct and good point. It seems like overall the GFS has a juicer airmass to work with, hence the blocking ridge(s) will be a bit weaker and more transient (i.e. progressive).

      • Pfirman

        I woke up thinking ‘three day window’, should be a lot of conjectures’ and, sure enough.
        Just what span of time is involved in ‘a little earlier’?

        • Transom window = A little earlier …LOL

          • Pfirman

            ???

          • I’m flummoxed this went over your head?

          • Pfirman

            Well, transoms are also the rear end of a boat, so there is that.

          • gray whale

          • Pfirman

            Say, since you chimed in here, did you notice my grape query?

          • gray whale

            Ya i wrote a response thinking that you’d get it via email, so afterward I edited it down to nothing since I put my contact info in. Do you get alerts from disqus if someone responds to your comment? If so, check that for my email address. if not then comment with your email, I’ll get an email notification and come back on to let you know I got it, than you can edit it away so your emails not in the comments section.

            Oh, and short answer: yes, or at least I can help you find something cool

          • Pfirman

            Thanks a bunch. This is so far down that few will read so I will just post contact info, which is…..
            pffirrmann@gmail.com
            What varietals do you have? You mentioned a few once. I typically make five reds each year and pay a buck a pound. Also make port. Used to make white too, but quit last year.

            At the moment I am looking for Grenache.
            Thanks again, David

          • Pfirman

            I thought I replied to you, but cannot find a record of it.
            pffirrmann@gmail.com
            David

    • BRP (Ventura)

      Great post CH, like you, I get a kick out of reading the various NWS Office’s Discussion pages. There does seem to be quite the variation in forecasts for this upcoming storm just 72 hours away! NWS Oxnard is very gun shy to even post 30% of showers on Friday, but looking at the recent 06Z GFS, it’s showing rain by noon on Friday in VTA continuing through Sat morning, maybe delivering up to 1/2″ here on the coast!

    • SlashTurn (Santa Barbara)

      Thanks CHeden. I was waiting for your take on the evolving situation…this is the time of year where forecasters are put to the test.

      Looking forward to the NAM 18z this afternoon…

      • BRP (Ventura)

        So this 18z NAM run should be available by 1600 our time today? I too look forward to seeing how this will fare compared to the GFS and Euro…

    • AlTahoe

      Open snow had 14-20″ of snow for lake level in yesterday’s report but like most storms this winter it is going to come in much warmer. I would expect 0-3″ at lake level with some good totals above 8k.

      • CHeden

        So, more precip and higher runoff?

        • AlTahoe

          The recent GFS runs have been showing much lower Precip in General so maybe 1-2″ of rain and a couple inches of snow. Looks like the heaviest stuff might be moving more south. There is time for that to change but the trend has been for less precip up here.

          • CHeden

            That does seem to be the recent trend in the GFS. Let’s see what the new 12Z run shows. The EC should be out by then as well.
            Personally, I’m thinking the 06Z run is too pessimistic. The current Pacific WV is showing much moisture and elevated IVT’s for at least some rapid enhancement possibilities. https://uploads.disquscdn.com/images/0e8009e9e65154b067e5cdee3b4e031075aa688b5b4041f215d5607f519ed4df.jpg

          • 82/83 El Nino Baby (San Jose)

            Great posts as always Cheden. I put more faith in your forecasts than the AFDs and your latest post illustrates why.

            Do you think the CF will stay coupled with the low pressure? I believe the couple of times “bust” was widely used on WeatherWest, it was when a CF became disconnected from the main LP and lost dynamics.

            I wonder if there a way for forecasters to predict this sort of thing, or is it just wait and see? If the latter, its surprising since we can pinpoint days ahead where a sever weather outbreak will occur (down to the country), but it seems like cyclogenesis off our coast is not predictable.

          • TahoeCard

            And let’s remember you live on the side of the lake where it doesn’t snow. There’s been multiple times this year that you have got 2-4″ and we have received 2 feet on the west shore.

          • AlTahoe

            Yeah this season has been very weird in that regard. But my point is that the forecast has been for huge totals in South Lake Tahoe itself, and it usually doesn’t verify. In normal winters we would reach the forecast or even over perform in like 80% of storms. In the last two winters we reach the forecast or over perform like 10-20% of the time.

        • AlTahoe

          Newest GFS that just came out shows the storm even warmer and wetter than any of the previous runs, not a good trend. Snow levels would be 8k during the heaviest parts. We would get some snow showers at the very end behind the front

        • inclinejj

          As was the Reno NWS yesterday. He quoted their forecast.

    • 805 Weather (Camarillo)

      Great summary! In some cases it seems almost predictable when looking back on this winter, but in other ways this setup is still a new player to the game..

  • weathergeek100

    From Howard Sheckter:

    “Climate:

    The Drums of El Nino are beating again. SSTAs over the Indian Ocean have not been colder at this time since 1986 and westerly wind burst are increasing. Scientists are being very careful at this time, about any hype about El Niño as they were burned so badly the Winter of 2016. Nevertheless, this one does bear watching. There is already a major coastal EL Nino occurring along the central coast of Peru causing major weather related issues to that region.”

    The amount of rainfall that fell in Peru in recent weeks is phenomenal. I looked up climate averages for Lima and about an inch falls there per year. I would like to see how much fell there recently with their “local el nino” pattern. All of this bears watching to see how it’ll affect us here!

    • Bartshe

      Another El Nino on the heals of the phenomenal warming beast we just had is not good news for anyone. More record global temps, more massive coral reef die-offs, extreme flooding, extreme drought, higher snow levels, etc. don’t see how anyone can really get excited about El Ninos anymore. El Ninos are high-octane global warming accelerants.

      • weathergeek100

        I’m not saying I’m excited. Global warming should be our number one concern as we study meteorology and climatology. This is obviously very concerning, as we just had a major El Nino. Are they getting more frequent? Maybe. I hope I’m wrong. I think one may get excited because it could mean drought relief for CA (though we saw that wasn’t quite true last season) but in reality, it’s just a sign of more extreme events as you point out. The problem is that our recent drought relief has actually been from abnormal weather patterns- the frequent ARs, etc. If an El Nino were to develop and bring above normal rainfall for SoCal, it’s good news (as they’re still experiencing some drought) but bad news overall. We need normal rainfall patterns to resume in CA (via regular GOA events) and this just hasn’t been happening lately.

        Oh, don’t even get me started on the coral reef die-offs. I’ve been reading the news on that. So depressing.

        • Bartshe

          Always interesting to post this stuff & glad you did, don’t mean to come off as discouraging, just my editorializing. Uncertainty is increasing along with fascination. Overall things are not on track to end well.

      • jstrahl

        There are some folks who don’t believe in global warming, so for them the only thing that maters is more Cal rain.

        • weathergeek100

          There are some folks who don’t even believe there’s been a drought in CA. They think the drought is ‘man-made’.

          • jstrahl

            And some of those folks keep dropping in here, carpet bombing the comments with geoengineering junk.

          • PRCountyNative

            Some people think we can grow the economy, and human population, forever!

      • Well If one forms it will have a different genesis. If a consistent -SOI there’s the possibility of a real east based event. Who was looking forward to 16-17 in April of last year? The IO has been warm for years. Big changes may be in the works. IOW I’m a little more optimistic about the possibility of one more El Niño may cool off the western Pacific.

        • 805 Weather (Camarillo)

          If you are thinking what I am thinking about IRT the after effects of another Nino response, we have much to discuss!

    • rob b-Truckee/East Bay

      for those interested here is Howard’s letter it was posted yesterday.
      http://opensnow.com/dailysnow/mammoth

    • scott

      He was pretty good at forecasting most of the winter this year so I hope it comes to pass.

    • molbiol

      I mentioned this two weeks ago and warned that if cooling makes it to the maritime continent, that could start to trigger WWBs which could result in serious trouble. So far winds are not showing any anomalies. I’d post an image but why bother

    • 82/83 El Nino Baby (San Jose)

      I wonder if there has ever been a modoki type El Nino, but Nino 1.2 focused. Meaning, maybe +3 or 4 degrees in Nino 1.2, but only +1 degreesin Nino 3 and maybe neutral in Nino 4.

      I know Nino 1.2 can go up and down quickly, but do not see past instances of prolonged warmth in Nino 1.2 and what that means for CA weather.

      It has been speculated that along with climate change, the main reason the 15/16 El Nino was not so Super for CA rain was due to Nino 1.2 being way behind the El Ninos of 97/98 and 82/83.

      • If you have a warm east and warm west and a cool center it’s has been called a La Nina Modoki. https://uploads.disquscdn.com/images/2a0eb489f01191a27934f60d89660051ffd135e970925d385dc53dda37f76446.jpg

        • 82/83 El Nino Baby (San Jose)

          Interesting. Maybe that is what we kind of had this year?? A warm Nino 1.2 (and portion of Nino 3) and high pressure placement along the dateline due to the colder Nino 3.4/4.

          • 805 Weather (Camarillo)

            It was categorized as a weak La Niña Modoki.

      • Chris

        I believe last year’s El Niño was modoki type.
        For it to be modoki, it doesn’t have to be cooler than average on both ends.
        The concentration of the warmest water just has to be in the middle.
        2006-07 was also modoki type El Niño.

    • SoCalWXwatcher

      “Scientists are being very careful at this time, about any hype about El Niño as they were burned so badly the Winter of 2016.”

      Indeed. Hopefully no one goes full Patzert on us this time.

      • They won’t hype it but it will be spun into myriad reasons to suit whatever Global Warming article must be written. Hang a shingle this is the year!

    • Arctic River (Suisun City)

      Well, since water always flows downhill (absent extremely high winds) and downhill is always south on the map, I’m sure there’s not even the slightest risk if flooding in the Delta, right? RIGHT?

    • Craig Matthews

      The depth and momentum of these portrayed systems across the eastern NPac into West Coast seams very remarkable for this time of year to me. And am wondering what the return frequency of such systems behavior, that is, systems straight streaming from the west into CA from the central- eastern NPac, would be for this time of year if this run were to verify?

  • Danlyle (Mariposa)

    Considering the outcome of 1969 and 1983, comparable snow pack, regional subsidence, limited capacity at Lake Isabella, and the forecast for extreme rain on the western slope of the southern sierra this week, seems possible that Tulare Lake might return.

    http://www.fresnobee.com/news/local/water-and-drought/article142100139.html

  • Charlie B

    Quickly finding weather stats for Peru is not easy. I did find an article that reported that the city of Piura, which is on the coast about 500 miles north of Lima has received 25″ of rain this year, with an average of between 1.5-3″ annually. Thus if that is accurate we are talking about 10x average. I do wonder about the accuracy of that report because those coastal areas are up against the Andes foothills, and I would think that rainfall rapidly increases with elevation, so who knows if the 25″ figure is in Piura itself or some higher location near by.

    • AlTahoe

      I saw an article somewhere a couple of days ago where they said that multiple cities had 5-10x their annual average.

    • inclinejj

      Not only Peru. I saw Columbia also had record rains and floods.

  • happ [Los Angeles]

    The irony that we carefully/ hopefully monitor every run of the models for signs of rain in California [especially during spring] when the PacificNW is looking for just one dry day w/o rainfall. Seattle/ Portland are nearing records for the amount of rainfall/ cloudy days and cool temps this spring. Many people up there would gladly send the abundant/ long-lasting moisture down to us in California. Here’s hoping that the weather gods cooperate and bring us an AR storm all the way down to the Mexican border.

  • alanstorm
    • 805 Weather (Camarillo)

      I’ll be on around 4:30 preparing another update on the dynamics of the first “1-2-3” system slated to kick this pattern off. Plenty to talk about.

      • alanstorm

        How the hell does it get down to 30° in April??
        Once this thing hits the Midwest, could be quite a tornado outbreak

        • 805 Weather (Camarillo)

          Unfortunately it’s not the Midwest they’re worried about… As has been the case this late winter, any systems heading into the west coast are being pushed east and funneled down into the Southeast US. These are bombs going off in the sky down there and tornadic statistics are already showing the strength of this season.

          • Wolfpack

            Being back here in NC the afternoon discussion did mention severe weather tomorrow night with a triple point low pressure from the southwestern systems.

          • 805 Weather (Camarillo)

            Yep!

          • Wolfpack

            I always keep an eye on what’s happening in Ventura County. Grew up over the Conejo grade in Newbury Park, class of 85, go panthers.

          • 805 Weather (Camarillo)

            Glad somebody does, lol this county is terrible when it comes to topics on anything meteorological here, they get shot right out of the damn sky.

          • Bobby M ( San Carlos/Tahoe)

            That’s the point I have been making since February

          • 805 Weather (Camarillo)

            I do credit you for noticing that very early on, it was a good call.

  • 82/83 El Nino Baby (San Jose)

    According to this map, the drought on the big island of Hawaii is worse than anywhere in CA. Quite surprising.

    https://twitter.com/MJVentrice/status/849324679462518784

    • happ [Los Angeles]

      ENSO conditions could guarantee no drought anywhere in California next year [well, maybe not guarantee]

    • Read the Legend for “S” and “L”

      • 82/83 El Nino Baby (San Jose)

        Good point. But I would argue that portion of CA will always be in drought as I can’t figure out what setup is needed for rain to get that far SE.

        Would be curious to see drought maps going back 30 years and whether any areas of CA tend to be in consistent drought.

        • If you go to the site it has a link for archives that go back to 2000.

        • PRCountyNative

          Or if ‘groundwater’ meant aquifers and they actually included that – then always in drought these days.

    • FolsomPrisonBlues

      This is awesome to see, at least for us in California. How many years has it been where pretty much our entire state was brown and red? Its a nice change from past years.

    • Nathan

      I have always found the drought designations for Hawaii to be perplexing. Hawaii, especially on the leeward side, has always featured mercurial subtropical precip patterns. Drought monitor seems too willing to apply drought designation.

    • 805 Weather (Camarillo)

      We’ve passed the torch and this coming year everyone else should feel the heat. IMHO not necessarily heat, but more climatic events are occurring on a much faster pace in new places just the same as we had to sit and experience 2014-’17.

  • Rio Rat

    Saw this on Stormsurf Mon, (overview of jet stream). Over the next 72hrs the wind energy centered over & off Japan is to move East consolidating on the dateline Wed, with winds building to 190kts & most of the energy falling into the developing trough in the GOA, offering good support for gale development, then pushing up into the North Coast on Thur 4/6. Beyond 72hrs the trough off Ca is to redevelop while moving onshore through Sun, continuing to support unsettled weather along the Coast & east into the Sierras.

    • PRCountyNative

      He rocks. Good site.

  • Just got this in the mail. Now, where the heck do I put the wind sensor??!!!

    https://uploads.disquscdn.com/images/e07fc521eab4a0c7cb9c3251a358ccea3e0b6fde1ce2d70babb75fb319e69311.jpg

  • Harpo (Chico)

    March 29th snow survey results from Lower Lassen Peak near Lake Helen.

    Over 20 feet of snowpack with over 11 feet of water content!

    LOWER LASSEN PEAK (47)
    Elevation 8250′
    River Basin FEATHER R
    Cooperator Pacific Gas and Electric Company, Rogers Flat
    Aspect NORTHWEST
    Exposure UNPAVED PARKING AREA, ROCKY
    April 1 Average 78.1″
    CDEC Station ID LLP

    Depth and water equivalent in inches.

    Date Measured Date Depth W.C. Density

    2/2016 25-JAN-2016 143.0 53.5 37%
    3/2016 23-FEB-2016 145.5 64.5 44%
    4/2016 30-MAR-2016 199.0 95.5 48%
    5/2016 02-MAY-2016 167.0 82.5 49%

    2/2017 26-JAN-2017 182.5 73.5 40%
    3/2017 28-FEB-2017 238.5 118.5 50%
    4/2017 29-MAR-2017 243.5 133.5 55%

    • Nathan

      That’s nuts…and all of it into Oroville.

      • Harpo (Chico)

        Too bad most of the water will probably be released to keep Lake Oroville low for spiilway repairs. Also, a lot of Lassen Park’s snowmelt drains directly into the Sacramento River via Deer Creek, Mill Creek, Battle Creek, etc.

        • Pfirman

          “Lassen Volcanic’s mountains, lakes, streams, and meadows are all parts
          of a watershed or an area of land that is connected by the water that
          flows over it. Rain and melted snow travel downward within a watershed until it is captured, absorbed, or empties into the sea. The park is comprised of four watersheds: Pit River, Battle Creek, Mill Creek, and North Fork Feather River.”
          Anybody know size of these in the park? Anyway, sounds like the melt hits Lake Shasta via Pit, Sacramento River via the creeks, and Lake Oroville via the NF Feather River.
          Interesting.

        • The net loss would only be about 1,000,000 acre feet to keep the level under bottom of the spillway. Water has to be released to maintain a 901 elevation level as well.

    • That be about 200 feet at 10:1?

    • 805 Weather (Camarillo)

      That is a pleasing dataset especially with a storm on the horizon.

    • Charlie B

      4-5 feet projected at Lassen out of this upcoming little spring disturbance.

    • Admode (Susanville)

      11′ of water content? Wow! I can tell you first hand that around 6,000′ the snow in the park was melting fast, a couple weeks ago. I can give you a report the next time I’m in there, but that could be may/june. Chaos Crags Campground area.

    • Thunderstorm

      That is very troublesome news for lake Oroville.

  • Bobby M ( San Carlos/Tahoe)

    Forecast now looks weak to what it was forecast yesterday, now looking at .5-.75 https://uploads.disquscdn.com/images/be1464c53a78a412c03c03ae7c9c24735e45287fa33e389cff27db10ba3d2b92.png from 1-3 inches. I have a hard time believing this because the storm looks amazing on the setup is great for big precip here!

    • Rio Rat

      It ain’t over till its over, the proof is in the bucket.

    • HUGE donut hole forming over San Carlos. You’re right

    • Bob G (Gustine)

      Never noticed the GFS bringing in 3 inches of rain to the Peninsula. Looks like about one inch. Still a good storm for April

      • 805 Weather (Camarillo)

        Agreed.

      • Bobby M ( San Carlos/Tahoe)

        oragraphics, even though I am at 140-200 feet I have received 7.5 more inches than a station in the flats a mile south of me

  • AlTahoe

    NWS Reno has knocked our snow totals down to 4-8″ at lake level but mentioned that there could be huge swings. So right now anywhere from 0 – 24″ is possible at lake level.

    “During the Friday night time period when snow levels are
    forecast to make a sudden drop model simulations have deviations
    of more than 3000 feet!”

    • matthew

      I liked this part :

      The last time Tahoe City recorded more then 2.5 inches of
      precipitation in 2 days in April was 2003, and the last time the
      Reno Airport recorded more then 0.75 inches in 2 days during April
      was 1988.

      This is adding to an already historic amount of precipitation
      received so far this winter. The northern Sierra precipitation
      index is getting close to surpassing the historic winter of
      1982/83. As of today the the 8 station (averaged) index has
      received 83.4 inches of precipitation which is above what had been
      received at this date in 82/83 and nearing the total for that
      entire water year of 88.5 inches.

      • AlTahoe

        That 2.5″ stat for Tahoe city is pretty remarkable as that is not a lot of precip for Tahoe city.

    • Bartshe

      House odds favor next to no snow in E.Sierra below 9000′, but put my money on a couple slushy inches anyway.

  • flyboy45

    The strong 180K 300MB jet has consolidated near the dateline and the nose of it has reached 165 W and heading for the CA coast. This is a very strong pattern and validates upcoming storminess.
    http://squall.sfsu.edu/gif/jetstream_pac_init_00.gif

    • 805 Weather (Camarillo)

      This is an evolving pattern just as the last cycles that rolled in.

  • Fairweathercactus

    Looks like the GFS is trending the way of the Euro for So Cal. It holds the ridge together a little better and shows a lot less rain for the area.

  • T’storm98 (Orcutt, CA)
  • mattzweck
  • Rainmaker (San Jose)

    whats up with the projected rain totals. San Jose is projected for 1.06 in, while cities around the bay area and farther north only getting anywhere between .50-.85. Storm stalling out over south bay?

    • SoCal Al (El Monte-SGV)

      Seems Oxnard is agreeing with your idea:

      “The trough will begin to tap into an atmospheric river later Thu into Fri with pwats just under 1.5″ off Pt Conception Friday morning. The other interesting factor is now both the GFS and ECMWF basically show the front and moisture plume stalling along the Central Coast Friday with the AR continuing to pump rain into that area all day Friday. And if the strong southwest winds of 40-50kt between 850-700mb develops as the models show this should be a significant rain event for northwest SLO County, perhaps on the order of around 5″ or so for the coastal mountains.”

      I don’t think we’ll get much here in SoCal…..maybe 0.10-.25″ with this system. Suspect it will be weakening rapidly similar to our last “storm” that dropped 0.21″ here on March 21/22.

    • 82/83 El Nino Baby (San Jose)

      Hope it c

  • happ [Los Angeles]
  • Full blog update tomorrow–Thurs/Fri storm looks very impressive for April.

    Meantime, I have substantially revamped the advertising on Weather West to address a number of concerns site users have had recently. These changes went into effect shortly before this message was posted. I would be curious to know if these changes have translated into tangible improvements with respect to user experience. Thanks!

  • happ [Los Angeles]

    What surprises me about this data is that only the Pacific NW has so many consecutive days of rainfall. Somehow I would have expected the Southeast U.S. to also have many daily storm days each summer https://uploads.disquscdn.com/images/1163729c76b6517344d6c2e56450d44b6158f4256c252a3ba90cc5781a6e6d11.jpg

    • RunningSprings6250

      The difference is the nature of the precip – localized popup tstorms doesn’t bode well for consecutive days of precip at any given station.

  • 805 Weather (Camarillo)

    As Daniel pointed out earlier the IVT chart on the GFS was quite impressive… Now compare that with current IVT forecast from the NAM. First two graphics are at 54 hours or during entry. However the last two graphics are at 66 hours for both models and as you can seen the GFS has way higher IVT values, the NAM is indicating better forcing on the north coast as the system pushes in than the GFS, but it’s not as strong overall in the IVT forecast. Check out the core placement in the 66 hr graphics as well… Another thing to note is how & where these lows will phase. https://uploads.disquscdn.com/images/fff7553846c56a0db845393c9783bbef180c3feb72fb319ced33e66146775bb8.png https://uploads.disquscdn.com/images/e42214138218c0d1469675dd9a83b6449b42d52f1f6c0ad6a363e12554241f71.png https://uploads.disquscdn.com/images/0c06daf1d0124c23b418e303972963ca1b72f1b0c3ec715a0281c780b2a3419a.png https://uploads.disquscdn.com/images/77b92ffd393e2c78d8054d8ebd4b5ad36ee3bafc2324de359974a1226b412e0a.png

    I would like to also add a little note that the trough ahead of Friday’s system or I should say the one right off the coast was actually supposed to be in the mix of things by phasing with Friday’s dual lows… This is no longer the case, BUT the system is actually showing even greater strength now on all models, this is a new development this evening. I will be on to update about the Euro and how it ties in with the other models, but I will say the Euro 12Z earlier today was really impressive in it’s shift south with impacts. I’ve added the comparison of 00Z Euro & 12Z Euro, have a look. https://uploads.disquscdn.com/images/bcb17bdbd89081335f120e7602a28bdb364ed73c6b97836ff1e7bbf44b0f775f.gif

    • Bobby M ( San Carlos/Tahoe)

      Awesome, snowpack above 10,000 in Southern and Central Sierras will be obscene , I saw 5 feet of snow in the forecast for Mammoth Mountain!

      • 805 Weather (Camarillo)

        Yea, I’d warn you though, snow ratios are a much different thing in April especially with a system that has a moderately strong sub-tropical tap also out of the norm for this time of year. Then again who’s saying anything is normal now?

        • scott

          I have seen some pretty nice forecast totals for Ventura and Santa Barbara counties, that far south. let’s hope is further south can get in on the action!

          • 805 Weather (Camarillo)

            I’m worried we’ll be under the influence of the subtropical tap more than anything… There is only one way that subtropical tap will work out down here. & that is good dynamics. Believe it or not the dynamics are actually very favorable with this, something we weren’t really able to achieve with the last upper lows that funneled a subtropical hose anywhere south of Pt. Conception. We’d get our orographics just fine, but this time is different.

          • SoCal Al (El Monte-SGV)

            The EC is definitely the stronger model for precip here in SoCal. Funny thing, it did a complete flip-flop from the GFS which in earlier model runs had more decent rainfall making it’s way down to our area. EC also shows fair CAPE values along the San Gabriel foothills around noon on Sat.

          • 805 Weather (Camarillo)

            Glad you took note of that, some of those CAPE values creep into the typical SoCal convergence areas… Interesting.

          • Mike Stephenson

            Hoping so!

    • alanstorm

      Good thing this is a fairly cold system. (right?) The last thing we need at this time is a warm AR.
      Even so, I’m expecting a decent rise in the major North Coastal rivers for sure by Sat.
      No warning or flood stages, but remarkable flows for this late in the season. Anything to help the ruined salmon runs up there will be welcomed.

      • 805 Weather (Camarillo)

        It will be a real watcher for this time of year, my focus is on the Sierra runoff and thunderstorm potential for this one.

  • K?ros

    From the latest Monterey AFD: “The Global Forecast System (GFS) is predicting a pocket of very heavy rain over the highest peaks of the Big Sur Coast of Monterey county Friday where rainfall accumulations maybe near 10 inches”. Hopefully that doesn’t pan out the last thing they need down there right now is a near foot of rain in a day.

    • Charlie B

      That’s a lot of rain.

      • Tangocity

        We’re going to need a bigger boat!

    • alanstorm

      That’s a nutty amount of Precip for 1 day!
      Would be a major catastrophy if that happened.
      CNRFC 6 day precip map for the entire weekend is at half that for the Santa Lucia’s
      Still, 5″ of rain would be HUGE

      https://uploads.disquscdn.com/images/782ddd271995244b5b7f79cceecd97069a4dc0204192a8a652487347770bb864.png

    • PRCountyNative

      They just opened the road from the last washout!

      There are quite a few places in the neighborhood where a little more rain would have caused slides. Roads are just hanging on in numerous places.

  • 805 Weather (Camarillo)

    Before the 00Z Euro comes out, K-values for this event are beginning to look pretty impressive. Highest CAPE values will be in place during Saturday night into Sunday morning across NorCal. Otherwise CAPE values are pretty modest for this time of year. https://uploads.disquscdn.com/images/09bf1f7de9486acd2b5aaf626515ba36b18659613baa8cc2896df8fed53ede3e.gif https://uploads.disquscdn.com/images/d2bfad896695acfdf76a295ef2ad199e977a796edaac145d3081e2d4b13b324c.gif

    • Tyler Price (Monterey/Seaside)

      Continuos bullseye right over the Santa lucia’s, southern Sierra Nevada, and southern Monterey Bay Area! Right in Seaside! Bring it in baby! Yes I will draw the clouds my way! ???????????

      • 805 Weather (Camarillo)

        I hope it makes it’s way right to you Tyler. You deserve to see this season go out with a bang! I guess we all do down here too, so send it south when finished my friend ;)!

        • Pfirman

          You will know it was good when a kayak floats by. (Yeah I know he never had one).

      • Bobby M ( San Carlos/Tahoe)

        Lets hope the boom is thunderstorms, that would be great!

    • Yolo Hoe

      You’re on fire 805 — thanks for the great posts on this upcoming grand finale to our year of years!!

      • Westside

        Grand finale huh? You guys have been saying that the past few storms.

        • Patrick from Stockton

          Yeah, lets wait to see what May has to offer. Years like this in the past systems have showed up well in to May. It ain’t over by long shot I don’t think

  • 805 Weather (Camarillo)

    I’m not gonna post any of the Euro 00Z other than these due to it’s backing off of the 12Z’s idea for a really gnarly scenario, however it is indeed still noteworthy, & yes even for SoCal. Tomorrow’s another day. https://uploads.disquscdn.com/images/c84bdec9b2c94a644dbf31ed8fb84e8f83881e97d86575e8e75739f3698ee637.png https://uploads.disquscdn.com/images/7e06fd858ae2f4149ed735c51092b86ac47c725440218a41c1c0abad3701a0a1.png

  • Bobby M ( San Carlos/Tahoe)

    The European Model has another and potentially stronger AR for the following Wednesday the 12th during the fantasy week 2 period. (Not as certain at this time.)
    Is this still in the cards

    • 805 Weather (Camarillo)

      It’ll depend on how these two systems phase. It’s a great setup for something big, but it’s still a ways out and looking at how the models are handling the upcoming system it’s going to be a tough call. https://uploads.disquscdn.com/images/71e8dea42004df3ee85055178adb4e1e51901860af671cbb93d6eb38639fee76.png

    • AlTahoe

      12Z GFS just got on board and shows it as well for Next Wednesday.

      • Patrick from Stockton

        I just noticed this on the 12Z as well. For those of us in NorCal who want more rain, looks like we are going to get it. They are forecasting a high this Saturday in Stockton of 60 and a low of 41. Welcome back February, wow 🙂 This could be an acitve April for us. MR & LR GFS are showing systems pretty consistently as of late.

      • jstrahl

        Eh? I don’t see anything like an AR for Wed the 12th.

    • Nathan

      Rag Dump might hit 500″ yet!!

  • e e

    Interestingly, the current Northeast Pacific cloud configurations on the satellite photos look a lot like the ones in the days before 1/4/08.

  • DelMarSD
    • Tangocity

      wow. They had extreme weather back then too.

      I remember that closure at Disneyland. We were in line on the submarine ride (it was different back then, no Finding Nemo characters involved) and they had to rescue a few of the people who had just gotten on the gondola.

    • Tyler Price (Monterey/Seaside)

      That last sentence was a jaw dropper for me…. “Wind knocked a man through a glass window” say what? ?? Wow just wow imagine how bad of a wind event that mustve been

      • inclinejj

        Knocked a man through a glass window. I would guess the wind caught him off guard, he lost his balance, and he put his hand out to brace himself and the window broke.

  • tomocean

    Auburn canyon at its sublime best. North slopes are still quite muddy in spots. Seasonal stream are running at pretty good rates. The American river has been receiving quite a bit of snow melt over the past week. It will be very interesting to see what happens during the first real heat wave.
    https://uploads.disquscdn.com/images/5be106c62e02342c8c364dc3dfbb045b1e8aa0cf0758dae7c6a6782899c2c1c5.jpg https://uploads.disquscdn.com/images/fc1d2d063b580034f88e71c4f76416d7e900b4e1bdbdebe7d7de6dc6a52abab5.jpg https://uploads.disquscdn.com/images/e2921200c5af28809cccfbaab321671b0e360baf2e61d276ac73357dd9213e24.jpg https://uploads.disquscdn.com/images/fc7cea8063b24bad531affb901d9bb0da00201981981a39e188ce2a993bc3228.jpg

    • Yolo Hoe

      Thanks for posting; sublime is great word choice! In your opinion, when is optimal timeframe to hike that area? I’d really like to get there for a day this year.

      • tomocean

        I would say that the first three weeks of April are the absolute best. With the rains coming this week, maybe into the first week of May.

  • AlTahoe

    Calm before the storm on my morning walk today. It was unusually warm out this morning as well. https://uploads.disquscdn.com/images/294bf0abd9e13d2eefd79f60b3e6b24ebc6fd0e79cc6d500f3318d06a05bcc6a.jpg

  • maddogokp
    • FolsomPrisonBlues

      Man that is beautiful! Great picture for sure!

  • rob b-Truckee/East Bay

    BA just posted his update, great end to the season for many resorts (April 16th a pretty common closing date).
    https://opensnow.com/dailysnow/tahoe/post/8481

  • Jason Jackson Willamette

    Interesting site showing the Bay Area Storm Index (BASI) for San Francisco.

    http://ggweather.com/basi.htm

    “Retroactively, I have determined BASI values for significant storms (see adjacent table) dating back to 1950 to see where they would rank. In the past 64 years I only found one events that rated a BASI of 10. This was the storm on December 12, 1995 that is the benchmark of strong windstorms among most Bay Area meteorologists. The three storms which rated a 9.7 or greater were on December 22, 1955, December 11, 1995 and the infamous Columbus Day Storm (October 12) of 1962.”

    https://uploads.disquscdn.com/images/604b549720e66b122e6d6ee3429ff22509b1786f767052947378ea11eed545c0.jpg

    • inclinejj

      Is that data from Jan Null’s website?

  • happ [Los Angeles]

    L.A. DOWNTOWN SUNNY 84 41 21 CALM 30.02F

    Again, USC is out of sync rather dramatically. Don’t they have backup thermometers or is this just another example of urban heat? Fullerton is 82°

  • Tazmanian

    some really strong winds now