Powerful Friday storm in Southern California; Warm & wet atmospheric river to affect Oroville Dam watershed Monday

Filed in Uncategorized by on February 16, 2017 3,195 Comments

Quick overview of current meteorological context

Very heavy precipitation expected across Southern California on Friday and Northern California on Monday (including the Feather River watershed). NCEP via tropicaltidbits.com

California is currently experiencing one of its wettest winters on record. Precipitation has been especially remarkable across the Northern Sierra watersheds, where liquid equivalent (rain+melted snow) is presently above 200% of average. Widespread flooding has already occurred across Northern California in recent weeks, and supersaturated soils are now leading to slope failures (mudslides and landslides) across much of the state. In additional to the “typical” flooding of regional rivers and streams that one might expect with prolonged heavy precipitation, California’s vast water storage and conveyance infrastructure is starting to crack under the strain–in some cases, quite literally.

 

Ongoing situation at Oroville Dam; levees also under severe strain

Late last week, the ongoing situation at the Oroville Dam in Butte County escalated dramatically when water overtopping the “emergency spillway” started to cause major erosion on the steep hillslope directly beneath the structure. Emergency evacuation orders were issued on very short notice to hundreds of thousands of people living across a swath of the eastern Sacramento Valley from Oroville to Marysville and Yuba City due to fears that the top 30 feet of the structure might imminently collapse, causing destructive flash flooding for many miles downstream. Fortunately, it appears that potential catastrophe has been averted for the time being–dam operators were able to increase flows down the damaged primary spillway and reduce water levels sufficiently to stop overflow and halt erosion. Since that time, a frenzied repair effort has been underway to shore up the emergency spillway and minimize further erosion if it comes into use again. A major challenge remains, however: dam operations cannot release water at as high a rate as they would under normal circumstances, meaning that the Oroville Dam may once again fill to the brim if storm or snowmelt-related inflows become high enough at some point over the next few months.

Additionally, serious issues have started to arise in the vast levee system that protects much of the Central Valley and Delta region from flooding. So far, there have not been any major levee failures in California this winter. But if the current forecast holds, the levee system will be under more strain by early next week than it has been in many years–and certainly since the locally dramatic ground subsidence which has occurred as a result of groundwater losses during the multi-year California drought.

 

Strongest storm of season (and perhaps in years?) in Los Angeles region on Friday

Southern California will be located under strong upper-level diffluence due to position under favorable “left exit region” of the jet. (NCEP via tropicatidbits.com)

A powerful atmospheric river, with a moisture tap extending all the way back to Hawaii, will make landfall in Southern California on Friday. This storm will be squarely aimed at the transverse ranges of Southern California, and it is very likely that the higher elevations of Santa Barbara and Ventura counties will see extremely heavy precipitation on the order of 10+ inches on Friday/Saturday. A modest surface low is expected to develop just off the California coast on Friday, further strengthening the cold front and generating the potential for strong, locally damaging winds across all of Southern California. The combination of copious moisture and strong dynamics will mean that even areas away from the mountains will see heavy–perhaps very heavy–rainfall. Los Angeles County, in fact, could potentially see one of its wettest 24 hour periods on record (even downtown LA could exceed 4 inches, with much more in the foothills). The NWS points out this storm will likely be the strongest of the season in these regions, and perhaps in the past 10-20 years in some of the wettest spots.

There are still some significant inter-model differences regarding precipitation totals–the ECMWF is not as wet as the GFS, and some of the high-resolution models stall the front west of Los Angeles. But confidence is pretty high at the moment that very heavy rain and strong winds are likely across SoCal on Friday, especially from Los Angeles northward. Widespread urban flooding is likely, and potentially dangerous flash flooding will occur in/near the Transverse Ranges and near recent wildfire burn scars. Impacts will be amplified by storm timing–the peak rainfall is expected between 3-6 PM in Los Angeles, which should make for a nightmarish commute. A few thunderstorms are also possible along and behind the front, some of which could bring some strong winds down to the surface along with brief torrential rainfall. All in all, I do expect this will be a very high impact storm across much of California.

 

Potentially strong, warm & wet atmospheric river headed for Oroville Dam watershed

A warm, wet atmospheric rivers with subtropical origins will approach Northern California on Monday. (NCEP via UCSD)

Unfortunately, the forecast for the Feather River watershed upstream of the Oroville Dam has become somewhat more ominous over the past 24 hours. Instead of a series of moderate, cold, and relatively manageable storms as had originally been depicted by the models, a rather strong atmospheric river is now expected to develop and slowly move across Northern California on Monday. The GFS and ECMWF agree that this storm will tap into subtropical moisture, bringing a warm and moist airmass into the region. Mountain peaks in the vicinity of Oroville Dam are not as tall as those further south along the Sierra Nevada mountain chain, so it’s easier for warm storms to produce exclusively rain (as opposed to snow) in that part of the state. The Monday storm may indeed be warm enough for most/all of the precipitation in that watershed to fall as heavy rain, which is not good news for current mitigation operations at Oroville Dam. Recent forecasts show a high likelihood of greater than 10 inches of precipitation over the next 5 days, with parts of the basin expected to approach 15 inches over the next 7 days. It is unclear at this point exactly what impacts this expected heavy rainfall will have on dam operations, but it’s clear this is not the forecast that DWR officials and emergency managers were hoping for.

Long-range model forecasts are showing the potential for an active pattern to continue through late February. (NCEP via tropicaltidbits.com)

The warm/wet storm on Monday will likely cause problems elsewhere, as well. Rivers and streams all across NorCal will likely rise rapidly, and many will flood. Additional mudslides are likely; widespread and potentially prolonged road closures are possible. We have also now reached the point where levees along mainstem rivers in the Delta and Central Valley may start to experience more serious problems–something that will have to be watched carefully in the coming days.

As recently as yesterday, it appeared that Northern California might get another break from the rain during the last week of the month. Today’s model forecasts, however, show no such rest for the weary. So at the moment, it it unclear how long the current active storm pattern will persist.

I’ll continue to post real-time storm and Oroville Dam-related updates on Twitter.

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  • sezwhom

    If you’re in the Bay Area, buckle up. We’re in for some serious hydro issues. I present you, the Excessive Rainfall Outlook. When the last time you saw “High Risk” painted over the Bay Area with Santa Cruz Mts. in prime focus?

    WHAT MAKES THIS EVENT STAND OUT EVEN MORE IS THE EXPECTED LONG DURATION DURING WHICH THIS ANOMALIES DO NOT MOVE MUCH. THEY STAY FOCUSED FROM THE CENTRAL CA COAST NEAR SFO EAST INTO THE SIERRAS FOR ABOUT A FULL 24 HOUR PERIOD. THIS SHOULD RESULT IN SIGNIFICANT RAINFALL FROM AROUND SAN FRANCISCO INTO THE WESTERN SLOPES OF THE SIERRAS BELOW SNOW LEVELS. A WIDESPREAD 2-4″ IS EXPECTED IN THE 48 HOUR PERIOD ENDING 12Z TUE…WITH AS MUCH AS 5-9″ ACROSS THE FAVORED TERRAIN. GIVEN THE EXPECTED PROLONGED PERIOD OF STEADY TO AT TIMES HEAVY RAINFALL…AND THE WET ANTECEDENT CONDITIONS…WIDESPREAD HYDROLOGICAL CONCERNS ARE LIKELY.

    • Thunderstorm

      777 jackpot. There have been these stalled AR’s before but never with full lakes and rainfall totals so high. Crystal Springs Reservoir is at 101% and goes to the bay thru city of San Mateo. Are they prepared?

  • sezwhom
    • matthew

      This is one time that I would be happy with a bust. It is going to be rough sledding for a whole lot of people.

    • Thunderstorm

      Unfortunately the river beds have not been maintained, this will in hind sight have been a catastrophic mistake!

      • Tuolumne

        There is a stream maintenance program run by the Santa Clara Valley Water District (SCVWD). They take out vegetation and sediment each year in areas where these tend to build up enough to degrade water passage over time. However, lots of channels tend to stay pretty much the same from year to year and don’t need this kind of maintenance.

        Under law the SCVWD also has an environmental stewardship mission with respect to streams under their jurisdiction. That means they can’t just go out there and ream them all out to maximize water passage regardless of environmental cost. A lot of this was done in the past and was very damaging.

        There are still a number of streams in the area that have not had flood control installed, or what exists is from a long time ago and is obsolete. However, these kind of projects are extremely expensive. While the SCVWD has a comprehensive program to retrofit all their urban streams with protection against the 1% (“100-year”) flood they are still a long way from meeting that goal.

        No, I don’t work for this agency and never have.

  • RunningSprings6250

    I’d imagine there’s some daily / alltime record rainfall amounts in SB/VT, anyone see a list posted yet?

    • max

      Just the precipitation charts for each County. Don’the know about all time records. Lot of good rain, tho’.

      • RunningSprings6250

        4″-6″+ daily totals in the coastal plains has to be daily records and some alltime daily records as well.

        • redlands

          would love to get a 4-inch daily total in Redlands — means Running Springs would get 12 inches of rain

  • Boromir

    March, April and May is the windy season. There always seem to get frequent strong WNW/NW wind events at that of year.

    • TJH

      No doubt about that. N/NW winds blow down the back side of high pressure, churning up the ocean. The coastal waters experience upwelling and cooling, and then comes our coastal fog…

  • Arnold Weather Fanatic

    Snow level just up the hill at the State Park. Hope it stays there!

  • Cap’n

    Light flurries just starting. It’s amazing how many days this winter have had some form of precipitation, even the calms between storms. Already at our 4th or 5th day in a row again of something falling from the sky with several more ahead. I’m heading to Serene Lakes up on the summit to do some work, radar shows it will probably be snowing lightly most of the day.

    • AlTahoe

      We picked up around an inch of super fluffy dry snow over night. It is clear overhead now but we keep getting these random burst of giagantic snow flakes

  • Boromir
  • RunningSprings6250

    Woke up to 33F rain and it just keeps going, it’s snowed or rained the better part of 48 hrs now, albeit mostly light, and chances of rain snow through tomorrow night has increased. We could use some more bigger storms and I’m sure we will get them at this rate but I am loving the cooler, wetter, cloudier times in between.

    I’m not sure what to call this rain, torrential drizzle, heavy light rain, light moderate rain…either way it is very saturating and welcomed!

  • Bobby M (This Year Was a Bust)

    Dear,
    Mother Nature
    We like rain and all but snow is good too, please drop the snow levels to 6,000 feet so flooding doesn’t destroy us
    Sincerely,
    Us

  • Storm Master (Sonora CA)
    • sc100

      If Sacramento gets 4.5 inches from this next storm, that will be amazing. Very few times in history has that happened.

      • Storm Master (Sonora CA)

        this is looking like too be the strongest and wettest AR event yet i need 3.50″ of rain or more too make it the wettest rain day of the season the last wettest day was JAN 22nd when 3.47″ fell i am hoping too bet that this time

        • Henry

          Any idea on the dynamics with the storm? It is not clear from the forecasts if this is a strong storm, vs a system of average strength that just happens to be very wet.

          • 82/83 El Nino Baby (San Jose)

            Thank you for asking. I am hearing no technical details on this storm besides pwats. As someone living in the shadow, the details make all the difference. The Nam showed 0.7 for SJ, which implies no dynamics with the system, but hope I’m wrong.

          • weathergeek100

            AFD says 1-2″ for the interior valleys down south with even less in the northern Santa Clara valley. I’m calling 1/2″ for San Jose.

          • 82/83 El Nino Baby (San Jose)

            Yeah. This would be by a mile the worst shadowing of the year for sj

          • Henry

            I see similarities with the January 7-8 storm. The first day had no dynamics, just very heavy orographic precipitation in the Santa Cruz Mountains. Then the atmospheric river shifted to the North Bay and stayed there for about 12 hours. Then on the second day it slowly shifted back to the south, this time with stronger dynamics and stronger winds. San Jose did not really get into the act until a couple of hours before cold frontal passage. If I recall we got about 1″ in San Jose and about 4″ here a couple of miles from Los Gatos.

          • 82/83 El Nino Baby (San Jose)

            I think you are probably right. Would love to hear Daniel give more in depth reviews of storms in addition to the higher level synoptics of the CA pattern.

          • Henry

            I suppose they know that this morning’s QPF predicting 2.88″ in San Jose (http://www.cnrfc.noaa.gov/awipsProducts/RNOHD0RSA.php) is likely to be way off the mark. This morning’s numbers are crazy, 4.48″ in San Francisco and 5.95″ in Lexington Reservoir.

          • sezwhom

            Yes, very high PW but helped along by a robust Low Level Jet which will greatly increase orographic lifting and…

            WATER ANOMALIES INCREASING UPWARDS TO 2-3 STANDARD DEVIATIONS FROM NORMAL THAT SEEM REASONABLE CONSIDERING CURRENT WELL DEFINED
            SATELLITE SIGNATURE OFFSHORE/JET SUPPORT

          • sezwhom
      • Nookx-Weather

        That’s what I keep thinking. If it literally happens shit is gonna be insane. I did notice weather underground dropped down the totals a bit for Monday.

      • alanstorm

        Jan 4, 1982?

        • sc100

          I checked NWS Sac records. Since 1900, only three times have 48 hour periods had more than 4.5 inches: the legendary Oct 1962 storm, 1986 and Jan 1995.

          • alanstorm

            ’86 was really bad! Larger storm than tomorrow’s, & was focused on the I-80 north.
            Disaster for Russian R.
            This one is a bit more narrowly focused, but 4″ in Sacramento will be CRAZY

  • Storm Master (Sonora CA)

    i new this would happen the model runs are now trending much wetter and colder has we head in too late FEB with more storms but they be colder storms this time around

    • TheNothing

      A true Storm Master would never doubt impending bad weather on the horizon.

  • Storm Master (Sonora CA)

    looks like we will be going from AR events too low snow level events

    • Boromir

      I like Cold storms toooo!

      • Bobby M (This Year Was a Bust)

        Yep I like seeing white on the east bay mountains which I saw with the last cold storm cycle

    • Bobby M (This Year Was a Bust)

      We haven’t had cold storms since Early to mid January!

      • sezwhom

        They’re coming next weekend and beyond.

    • Sublimesl

      Almost all the low snow level events this winter have morphed into high snow level events. I’d be cautious against buying into this one

  • RSpringbok

    Here’s some good drone video of the Lake Berryessa vertical spillway, aka the Glory Hole. Shows the spillway, the dam, outlet and a couple of landslides in the area.

  • Bobby M (This Year Was a Bust)

    Got an inch or two at lake level at Kings Beach last night!

  • Storm Master (Sonora CA)

    last year we had one of the most strongest EL Nino ever and it failed this year we dont have EL Nino and look we have been getting flooding rains since early JAN

    • Charlie B

      North half of state have vary wet October to. With some hi water

      • Bombillo1

        We had 19 inches in October, which was rationalized as us having benefited from one off events. The truth was that we were getting some kind of an event every week then as well. The atmosphere was trying to inform us that we were under a different regime. This notice was mostly ignored at the time and we still have not come to terms with this.

        • alanstorm

          Reminds me of big ElNino years of the past

        • Microbursts

          Totally agree with you Bombillo….. i remember Daniel trying to keep us modest with his constant updates about how the models were all showing a dry winter … in fact each month cfs showed dry before doing an about face a few days before the turn of the month … all I have to say is all the mets got this winter wrong on a large scale (not that anyone is complaining)… even BA undershot this one … no disrespect to them but can we finally have an open discussion about how our long range models suck??? ????

          • Bombillo1

            I was hoping that something was learned that would help making better LR forecasts. Unfortunately what I am reading is that this winter’s character is being explained by the usual spaghetti test of Arctic ice, SST’s, west PAC warmth etc, whatever thing that may stick. Perhaps too soon to say but unsatisfying nonetheless.

          • Microbursts

            Agreed…. that being said we all felt the new pattern establish itself and saw it and a certain sense of intuition helped many begin to realize that we were entering a wash… rinse… repeat type of cycle that honestly began as you alluded to in October … just surprised so many mets (except Howard tbh) continued to bang the dry pattern drum until about … heck many were saying February was going to be dry … in fact some are still saying march is projected to be dry ?.. I think we are in for march march more ???

          • Bombillo1

            I am in complete agreement, in addition to any prongs about March. Until we can have a satisfying answer as to exactly why we had this record season there is no reason to dismiss the possibility of a wet March or even April, up North here anyhow.

          • SlashTurn (Santa Barbara)

            All mets missed…but the eastern Sierra real estate agent nailed it!

            The established scientific community will not sway into fringe theory’s which is why progression will never move forward in meteorology without breaking away from the widespread dogmatic institutional format…

            The reductionist mind is strong willed.

          • Bombillo1

            Perhaps so. It must be science based for me to buy in. No chi flow charts for me.

          • SlashTurn (Santa Barbara)

            Ha. I’m not poo pooing main stream science at all, it’s just to arrogant at times.

          • Tuolumne

            Fringe theories are almost always wrong. The few times they turn out to be right doesn’t change that fact.

          • SlashTurn (Santa Barbara)

            Daniel simply disregardes the sun spot cycle theory because it was never in his curriculum. Period. And that unintentional closed mind to something that isn’t in his make up limits expansion. IMHO

          • Bombillo1

            Something seems amiss. We are wandering in the dark about this stuff. No one is crying “Eureka, look at this that we have not been paying attention to!”

          • Tuolumne

            Are you claiming that meteorologists and climate scientists haven’t looked for a correlation there, that there is no significant peer-reviewed literature on the subject, or if that there is that Daniel hasn’t looked at and considered it?

            I’m not making a claim one way or the other because I don’t know the answers to those questions.

            I do know that you’re asserting that not having something in your curriculum means that you’ll never consider it later, and I know that’s just not the way good researchers work. That’s also not my experience in grad school, where going beyond what was in class (on my own, with no direction from faculty) made a favorable impression on my professors.

          • Patrick from Stockton

            Boy you got that right! I remember at the end of October the news was talking about people being worried that was it and it was dry from that point forward. How wrong they all were….

        • RunningSprings6250

          It never happened…

        • Paul Abrinko

          I totally agree with Bombillo as well. I’ve posted this before but it bears repeating: I heard during the drought of the early 90’s that the amount of precipitation that falls in November has a very strong correlation (about 80%) to how wet or dry the following winter will be. Seems like pretty strong evidence that precipitation patterns that set up in the fall have a tendency to stick around for the winter. Of course, correlation doesn’t prove causation but it can suggest it to varying degrees. 80% (if that figure is really true) is something I’d put my money on.

          • Tuolumne

            I just ran the SF rainfall data from 1849-2015 and got a correlation of 0.42 for November precip vs. the whole July-June water year.

            I think the 80% figure is bogus. It certainly doesn’t jibe with my personal experience, where I have often been painfully disappointed or pleasantly surprised by what happened after November.

          • Bombillo1

            Tuolumne, is there anything to be taken away from our experience this year? In late September of this year, are we going to be standing on the shore of the 17-18 winter as naked as we were last September?

          • Tuolumne

            I have no idea. Like many, I’ve become accustomed to being Charlie Brown in recent years, and having the rain/snow “football” snatched away after a brief period of promising precip. Ha ha, joke’s on us. So, I keep finding myself seeing all this rain and snow as not indicating an exceptionally wet winter, and just being a wet period in what might end up as a somewhat better than average winter.

            I’m really trying to get myself to truly realize that this is in fact an epic winter instead of just a lucky couple of months to be followed by several dry ones. It’s like I won’t really appreciate what we’re having here until it’s over and in the record books. Then I can look back and say that was a great winter, and too bad I didn’t enjoy it fully because I was too afraid that it was just a fluke period in a merely slightly above average winter.

            There’s been lots of discussion here over the past couple of months about why we’re getting all this rain and snow now, and I really can’t add anything or point to which reasoning or facts are the right ones. I don’t have the technical chops for that. But winters at least reasonably similar have happened before in my lifetime, albeit with cooler average temperatures than we’re having these days.

  • Bobby M (This Year Was a Bust)

    Looking down into Truckee and the valley with mountains behind it to the northwest https://uploads.disquscdn.com/images/ca577a839afca97810c40c02d44c4a66b330997d758be3b460eed7c9f059856c.jpg

    • Boromir

      Its sideways

  • Microbursts
    • JMS (NE Fresno)

      What’s your normal year

      • Microbursts

        Normal is around 60-65 inches

  • Dan weather maniac

    Reporting from groveland near Yosemite. Soggy mess everywhere rivers full streams full water on roads, and rain/snow(~6k) on and off all day.

    The dead tree situation is very bad, picture below drastically understates the amount of grey and brown in the forests.

    Here is the don Pedro for stormmaster… pretty full

    https://uploads.disquscdn.com/images/ff932a2d79af46a0c8a97b9f418cb2430a024ed3b8ce6dc79ec5c4ae773ea8f5.jpg https://uploads.disquscdn.com/images/696aefd3b09d780b1c79c734b285173c8d431607d8c4d9e87388b384c164d20c.jpg https://uploads.disquscdn.com/images/c17a3f8b4c1b2813661bb5cd21b5863dda3fd74a36f374f319f44c4db2b5fca7.jpg https://uploads.disquscdn.com/images/93af6a0cf3668fc3f3883862405729c8600dfbd97117af10a6e7b11eb1a33598.jpg

    • Freddy66

      If only they could have held on a little while longer

  • redlands

    redlands • 11 hours ago

    Redlands, Ca — Southern Ca — Rainfall Stats
    Feb 17-2017 — 1.42
    Feb 18-2017 — 0.20
    ———————–
    Total 1.62

    Well this storm for my area wasn’t the storm of the century and or the storm for the last 10-20 years. Redlands, Ca had similar totals this Jan 2017. We only had max-rain rates of 0.50. No high winds — only a gust of 24 mph — was mostly still. I know others early today make the statement of — it underperformed. Lookin at the NWS rain stats Redlands, Ca didn’t do that bad. I know a few places got some freaking high amounts – but mostly bout 1-3 inches. For my area think it was over blow. Media like to make a mountain out of a mole hill. The 1.62 was nice – but not record-breaking

    What did others get in Southern Ca — rain/snow totals

    • RunningSprings6250

      Redlands, it was never forecast to be anything very spectacular for the far inland ‘Inland Empire’ – the hullabaloo was for the area concentrating around SB/VT into northern/western LA and Orange County. Areas on the edge of the locations noted had a huge boom/bust potential and some busted….

      • redlands

        what rain totals did those cities get ??

        • RunningSprings6250

          Do you read here at all or only post?

          The weasel that is in SB but his wife is in Shasta recorded 8″ in Santa Barbara! Totals of 4″-7″ all along SB to Ventura and more in the mountains.

          • mount shasta, not “shasta” (a different town by redding)

          • RunningSprings6250

            They shouldn’t be naming towns so closely, what is this Oregon?!

          • i agree it is very confusing. i know of a lot of people who were heading to mount shasta and ended up in “shasta” by redding.

          • Bombillo1

            How about Eureka and Yreka? Arcadia and Arcata?

      • DManSA

        When Los Angeles and Irvine were forecast to get 4+ inches only a day before and even over 3″ that morning, I would say them getting under 1.75″ is a bust. While the VT/SB got high rainfall numbers the rest of the area got a bust.

        • RunningSprings6250

          That’s exactly what I said – what’s that to do with Redlands CA? ???

          • DManSA

            Lol I see now. I misunderstood what you said.

      • redlands

        What did you receive in Running Springs, Ca —

    • Microbursts

      You live in Redlands !!! That’s a solid storm total … be happy with it or else runningsprings will send you the donut hole of death in the next storm ????

    • Tom

      I got a little over 2 inches in Trabuco. Expected about 3 from the forecasts. Good solid storm, with brisk wind. From what I saw the best action was north and west of me. The media market is large and many areas did have big totals.

      • RunningSprings6250

        I think a huge problem is the prominence of LA centric news outlets in the ‘greater’ LA area, so many people think a forecast for LAX etc is the same for anywhere from Ventura to Riverside…

    • William_LeGro

      about 2.8″ in central Los Angeles, about 1/2″ more than Downtown, probably because I’m on a SW-facing hill

      not a bit of snow…I’m shocked!

    • SoCal Al (El Monte-SGV)

      Received 2.70″ from this storm which was less than the Jan 22nd storm (3.03″) for my area. Though it was not the storm of the decade, it was one of the windiest in these parts in many years. Had constant 15-25 mph winds, with gust up to 42 mph, which lasted for 3 hrs.

      • redlands

        Redlands only got 1.62 from the 2 day storm —I got similar one day totals in Jan 2017 — no high winds in my area like were advertised — no 10-20 year storm . You got bit over inch more than I did — guess its your closer to the coast than Redlands, Ca. Whats your total since July-1st 2016

  • RunningSprings6250

    Sideswiped by the systems to the north all week and then there’s this – I like! https://uploads.disquscdn.com/images/f2e4abba96f27bc910c0e8d1237c7efc2bdc8876dd84a2943b9722cf5fb40d69.gif

    • Freddy66

      Looks like some snow for you !

      • RunningSprings6250

        Indeedaleedoo!

  • SantaCruz

    Weather underground just slashed the forecast by half for scotts valley since last night. Calling for 3.5 vs 6+ yesterday. Guess we are no longer in the bullseye?

    • Henry

      How accurate do you think Weather Underground is compared to the NWS? My impression is that the commercial weather outfits just take the output of the NOAA forecast models and package it for public consumption. I’ve also heard that some of the commercial forecasters would adjust some figures such as probability of precipitation, to avoid disappointing consumers with surprising weather outcomes.

      • Nate

        The NWS point forecast is by far the best tool out there for rainfall totals. They’ll update it maybe ~2 times as the storm approaches, while Wunderground will do that 10 times, with the NWS always being closest in the end. Wunderground almost always overestimates. I’ve also noticed that they change their forecast based on what’s showing up on the radar sometimes, which makes for some pretty inaccurate forecasts.

    • Nookx-Weather

      They have cut our forecast in placerville by about 20% since yesterday

    • sezwhom

      NO….even MRY just updated their 10 AM AFD with shifting focus of heaviest rain around SC Mts. to San Mateo. WPC QPF has bullseye on SC Mts.

      • SantaCruz

        Hmm interesting all the different takes they have on this. Either way we don’t need anymore here in SC Mnts. Soils can’t take anymore. If we do get the bullseye our roads are going to get even worse…if that is even possible

  • Storm Master (Sonora CA)
  • 82/83 El Nino Baby (San Jose)
    • Microbursts

      Wow … what a beast that was !!!!

      • RunningSprings6250

        That thing had a raging hARd on!

        • Microbursts

          It’s like watching someone park a bus in a motorcycle space

    • alanstorm

      Look at the width of that frontal boundary! From Oregon to PT Conception.
      “There is NO escape!”- Darth Vader

    • Indeed, Monday storm is not of that magnitude. But context matters, and given extraordinarily wet antecedent conditions, it could have similar impacts.

      • primarily because it is expected to stall out in a high impact fashion and location, right?

        • sc100

          Pretty much. And the rivers have been dealing with high flows for about a month and a half now. Longest such period I can ever remember. Makes it more likely to see levee breaks. And of course, so many dams near capacity.

      • 82/83 El Nino Baby (San Jose)

        Very true. However, surprised at the current look of the incoming storm. Not easy to discern compared to ARs from earlier this year.

    • sc100

      Might have been the biggest storm to hit Norcal since at least 1862. Feather River and American River watersheds had their biggest recorded inflows from that storm. Imagine if we had one of those now! Flood control system wasn’t stressed at all before those storms came in. Very different now.

      • alanstorm

        Dec ’64 Storm could give it a run for the money. Was aimed further north. Highest peak flow of any CA river in record was Eel R.
        36 counties declared disaster

    • Bartshe

      Two storms, two winters, both couldn’t be more different.

  • Thunderstorm

    Check out climatereanalyzer.org shows the biggest dip in the jet stream I’ve ever seen. Dips down the west coast all the way to the equator then swings back up west of the Yucatan and then thru south Florida. Winds up to 22mph in gusts already from SE. SF bay area by Fremont. I see San Jose and SF under flood watches. Where ever this AR stalls people will be unprepared as usual. Lots of roads will wash out in the mountains. Food and gas will start to become a problem!

    • alanstorm

      Food & gas are always a problem esp if you chow down at Taco Bell during the storm?

  • Shane Ritter
    • Unbiased Observer

      Unreal how dry it had been, it’s too bad this year didn’t happen a couple years earlier and we could have saved millions of trees.

    • William_LeGro

      Wow. Excellent illustration of just how bad it’s been.

    • Bartshe

      rinse and repeat for the decades ahead, but with warmer temps forcing more extreme changes

    • weathergeek100

      Where is this cam? Glacier point?

      • rainingonmycactus

        Sentinel

        • Tuolumne

          Sentinel Dome, for those not familiar with the area.

  • BRP (Ventura)

    As of this morning, 19 Feb, lake Casitas is currently standing at 41% capacity. It’s hard to believe and it’s extremely frustrating to think that it’s watershed received 10 inches of rain and the lake has only increased 2% in 5 days. Could “they” be purposely keeping the diversion at a lower CFS rate to justify rate increases this summer? The conspiracy is gaining ground…

  • Unbiased Observer

    Ended up with a storm total of 0.96″in Bakersfield, the airport here only got 0.38″…ouch!

    • Darin

      Is Bako pronounced like Back-o or as I read it Bake-o? The whole no rain thing plus warm valley makes me think bake, as in all the time, dry and hot.

      • Unbiased Observer

        Pretty much…it’s pronounced bake-o.

  • Coldspot

    1/2 ” of wet snow this am at 2800′ in Scott Valley (Siskiyou County)

  • Storm Master (Sonora CA)

    winds starting too pick up here now

  • Chris
    • sezwhom

      Release all they want but by Monday night into Tuesday, Coyote Creek to Guadalupe is going to have some serious hydro issues.

      • Chris

        Probably unprecedented. I have no memory of a huge storm striking when the dam was already overflowing.
        I have lived here since 1980.

  • Will be writing a short post today to update regarding high likelihood widespread and severe flooding this week across NorCal.

    • Chris

      Thank you for doing this. I”m most curious if the trend is to move north of the Santa Cruz mountains or keep them in the bulls eye!
      The picture below is from Anderson Reservoir in Morgan Hill. In my 36 years of living here, we have NEVER had a huge storm like the one expected on top of this runoff.

      • LBurk

        We here in Ben Lomond need to be NOT in the bulls eye. There will be so much property loss if we are.

    • PRCountyNative

      The Santa Lucia mountains portion of Monterey County is having issues. Roads are crumbling flooded blocked. Sounds like the Santa Cruz mountains are similarly affected.

      It looks likely that one or both are going to face even more and worse in the coming days.

    • Bombillo1

      There is an uninterrupted string of foothill level locations along the Sierra and Cascade mountains that are well over 100 inches of rain. The coastal range is also well into record territory. Rain has a cumulative affect, how is it that we are looking at record rainfall this year yet no calamity? It can’t be and in the next 30 days we will know calamity.

      • RunningSprings6250

        Otherwise you’ll be known as the Bombillo who cried wolf. ?

        • Crank Tango

          #calamitybust

        • Bombillo1

          The prediction business in a notoriously tough gig.

      • gray whale

        Yikes. In my book no calamity is better than know calamity.

        • Bombillo1

          I thought you knew her, in the biblical sense.

      • AlTahoe

        I have told everyone up here in south lake, that I think 50 and 80 will be closed for extended periods after this storm. Especially 50. Nobody up here believes anything is going to happen. 🙁

        • Bombillo1

          No one anywhere really sees this as we do, those of us living in the big water shed sites. I do understand, folks in the Bay Area or other valley locations are getting .6 inches from these storms. The watershed/wet locations are routinely knocking down 4-7 inches per storm.

          • Tuolumne

            It would be really useful if someone did a statistical analysis of how far over normal the valley locations have been this winter vs. orographically favored locations. Orographic enhancement depends on the kinds of weather system coming in which is not the same year to year. This is just one of the many things I’ve learned from this site.

          • Tuolumne

            I should add that I have been in awe of the daily and cumulative rainfall totals put up by you and Cap’n this winter. Really, really impressive.

        • Bartshe

          prophets only come from out of town.

          • Bombillo1

            I look for an unusually bright star shinning over their houses.

      • Tuolumne

        It’s not a record winter in most places yet despite some records falling here and there. But with this incoming storm and what seems to be a very persistent wet pattern, we have a decent shot at having a lot more records breaking along with a lot of overstressed hillsides and infrastructure including levees.

        • Bombillo1

          Daniel’s preamble above starts with “one of the wettest winters on record”. We are at #3 in my 27 years here. Maybe this is just semantics but…I should also mention it is Feb 20th. Our big years had rain well into May.

          • Tuolumne

            The map I saw just recently showed a pretty good swath of area in CA and NV where this is the wettest start ever recorded, but not most of CA. IIRC this record area included most of the Sierra.

            Agreed that we still have a long way to go – 2 more months that are often heavy and 2 more beyond that where we sometimes get some pretty good rain/snow in the mountains.

          • ThomTissy

            Where I am in the SC moutains we are already 9″ ahead of the 98 El Nino. Roughly 76″ so far this wet season and it has been nothing short of an absolute disaster. The mountains roads and freeway are in terrible disrepair. The county’s plan is to “create more jobs in Santa Cruz so that the mountain residents do not have to commute into the Silicon Valley” as opposed to infrastructure repairs/upgrades. Keep in mind Santa Cruz is a decaying shit hole that only benefits from its proximity to the Silicon Valley, has an unemployment rate well above the state and national averages and has one of the highest per capita homeless rates in the nation. It’s as if one of these shit head councilors actually believes he has the ability to create a thriving business environment in Santa Cruz.

    • alanstorm

      From what they are showing on the models, it’s truly a Bay Area deluge.
      Reminds me alot of Feb ’98
      Starting Monday night, WATCH OUT:
      San Gregorio & Pescadero Cr
      San Francisquito Cr in Palo Alto
      Los Gatos Cr (Lexington at 101%)
      Corte Madera & San Anselmo Cr
      Coyote Cr San Jose
      San Lorenzo R & Soquel Cr

      Oh, & they may as well shut down Niles Canyon ahead of time

      • Tuolumne

        Guadalupe River in San Jose.

        • alanstorm

          Screw it- EVERY stream in the greater Bay Area!

    • weathergeek100

      This is insane. Just a few days ago the NWS was mentioning that the pattern will stay wet, but subsequent storms should be weak and fast moving. So the thinking was that ok, it’ll keep raining, but at least water sheds won’t respond as quick as they did earlier in the month and last month.

      Now we’re talking about another major heavy rain event with the potential for disasterous flooding. It’s quite remarkable how models have consistently beefed up qpf as we get closer to the event. This has been the case all winter for these AR events. Very interesting.

  • DelMarSD

    Storm total here is up to 2.2, as we had light/moderate showers last night and this morning, some of which did not show up on radar.

    In other news, the latest GFS had a wonderful surprise! A storm for So Cal 6 days out. Hope it sticks.

    • stormsurge10

      How powerful is this one?

  • Storm Master (Sonora CA)
    • Darin

      I think that’s the first time I’ve heard “danger stage”. I think my brain capped out at flood. Seems like flood is dangerous to me.

  • sezwhom

    Updated WPC QPF from 4 PM tonight to 4 PM Monday. I see a lot of rain over Santa Cruz Mts. and Feather River Canyon. https://uploads.disquscdn.com/images/1fd3bfbe01171a8eca1a6378e67a64529e6ffedb4384a630218b2e875878d0e0.gif

    • Jim

      I assume they don’t take into account the possibility of it stalling ?

  • rob b-Truckee/East Bay

    Winds picking up while skiing. Enjoyed some sunshine earlier, and this “snowbow” over Donner Summit! https://uploads.disquscdn.com/images/b207a6ce6f8763a454d757242e1404eee49309954fc3ec531e9066169ca3330f.jpg

    • Where are you skiing at?

      • Cap’n

        The gnar

      • rob b-Truckee/East Bay

        Tahoe Donner, too busy a weekend to drop big $$ at some other resort.

  • Charlie B

    Toulumne Meadows winter rangers reported over 20 inches of liquid precipitation in January with over 200 inches of snow. More in February and current snow stake reads 126″. Although it is 8500 feet it is far from the wettest place in Yosemite. Normal Jan-Feb usually sees only about 4.5″ of precipitation per month (about 50-60 inches of snow I would guess).

    • Unbiased Observer

      Any idea on where the wettest/snowiest place in Yosemite is? I always assumed it was that area, but I heard those numbers too and was surprised at how dry it is there.

      • Charlie B

        Glacier Point is probably about the wettest. 7k feet on west slopes.

        • Tuolumne

          I’d pick a southwest facing canyon at around that elevation. There are lots to choose from in the north part of the park. None have weather stations and only one I’m aware of (Slide Canyon at 9200′) has a snow pillow station.

    • Tuolumne

      Tuolumne Meadows is in very much of a rain shadow from the Cathedral Range. Check out the snow pillow reports from the Tuolumne and Merced watersheds: http://cdec.water.ca.gov/snow/current/snow/pillowplots/TuolumneMerced.html. TM always lags, every year.

  • gray whale

    It still seems like snow levels are not locked in on the models for the next couple days. Maybe they could surprise and trend downward? Or at least drop more quickly? I know the moisture is from a warm source, but here in Placerville there’s been colder than anticipated air in place since the last front.

    Fingers crossed

  • BeerguyOE

    Video of the Salinas River Elm Street in Greenfield

  • Nookx-Weather

    Long term forecast- Are we screwed after this storm and possibly something small next weekend?

    • weathergeek100

      Screwed as in what? Too much rain in the long term? Probably. Hopefully not. We need to dry out.

      • Nookx-Weather

        We need more rain!

        • Aussie Joe

          It is a matter of rate. We need rainfall events spaced well enough apart in order to avoid flooding and damage to infrastructure. At this point we are looking at too much rainfall in areas that are already saturated.

          As to the long term deletion of groundwater – only a significant change in how we manage that resource will make a difference – so it is more of a political challenge than a meteorological one..

      • RunningSprings6250

        That’s what being inside the house is for…and weatherproof outerwear.

        • Crank Tango

          I hear weatherproof underwear also helps during foggy conditions.

          • Bombillo1

            Most helpful in groggy conditions

          • Aussie Joe

            ..but ensure the emergency spillway is not required…

  • Someone else

    Oh look, they are turning it on just in time to:
    A) save us, or B) destroy us
    https://hackaday.com/2017/02/18/40-acre-haarp-rides-again-and-they-want-you-to-listen/

    In all seriousness, I post this not to be an instigator, but to shed some light on what it actually does.

  • Charlie B

    I tiled this picture “blue sky.” It has been a rare phenomenon this winter. https://uploads.disquscdn.com/images/b400a68657547e10074fbfbd4ec9cd6b7ea01ef6111f7d404b55f7e15a84467f.jpg

    • Mike Stephenson (Riverside)

      Incredible shot!

    • rainingonmycactus

      It’s sideways.

    • Chris

      I think this is “fake news”. You stole this picture from somewhere else in the world.
      This CAN’T be in California 😉

      • Tuolumne

        It was, for several years that recently ended. He didn’t say when the photo was taken.

    • Tuolumne

      What camera and lens? ISO? Love the depth of field!

    • Bombillo1

      I bought a business once that had a lot of that.

    • Aussie Joe

      Frame it and send it to your local modern art museum (make sure you mention that you are already famous…)

      • redlands

        don’t complain — wet season is very short — then we will go 10-11 months straight with sunny n hotter with no rain

  • Nookx-Weather

    Is there online weather training courses? Or a training website? Free or paid?

    • Mike Stephenson (Riverside)

      I think you can find college level meteorology courses for free online that might be interesting to read. If you have CA specific questions here everyone usually loves to help

    • kelpking (Linda mar Pacifica )

      Look into USFS S-190 and s-290 lots of good info as it relates to firefighting. Good intro to basic concepts

  • Nookx-Weather

    Weather underground just dropped placervilles rain totals again by about 20% we are now down about 2inches in total precipitation in the past 24 hours…. Bust

    • DManSA

      Lol you are still forecast to get close to 4″ tomorrow, I would hardly call that a bust.

    • DelMarSD

      BUST!

    • weathergeek100

      Oh no! We’ve had so little rain this year here in NorCal. What are we going to do? What an awful drought. There’s just no relief whatsoever!!!
      ;p

    • FolsomPrisonBlues

      I am fine with that. So much is flooded. We need a longer break before we get these massive downpours. The ground is beyond saturated at this point. Any rain we get now is just runoff to who knows where.

  • mogden

    • Crank Tango

      So cool. I remember seeing pics in Thrasher 30 years ago of guys skating the Glory Hole, and wondering why they called a horizontal pipe that. It took me 30 some years, but now I get it!
      http://www.streetcanoe.com/images/2011/05/alanpoach-600×902.jpg

    • Darin

      Between ‘Highway to Hell” and “Thunderstruck”, I think AC/DC wins for band most used as background music in a PowerPoint or video.

  • Tyler Price (Monterey/Seaside)

    Beenn getting on and off light rain showers all morning ahead of the storm

  • Aussie Joe

    On the topic of groundwater resources and loss of natural aquifers – any idea if it might be feasible to use fracking techniques to create new aquifiers? I have no idea what volumes of water one could store this way, although I suspect it would take 1000’s of wells to make a difference.

  • DelMarSD
    • weathergeek100

      There’s the bullseye on Del Mar/La Jolla!

    • Jeff

      Ended up at 1.84″ for Friday through sunday in Scripps Ranch in San Diego

  • gedawei