Well, it does certainly appear that the remarkably quiescent and dry weather pattern that has persisted nearly throughout California since November is finally coming to an end. After more than two months of extremely dry conditions during what is normally the height of the rainy season, nearly the entire state has accumulated some truly impressive precipitation deficits. Most of Northern California is experiencing hyrdological drought according to NOAA’s Palmer Drought Severity Index, with a good portion of the Sierra Nevada squarely in the “severe drought” category. Fortunately, though, these metrics are based primarily on short to medium-term soil moisture, which (as those who have lived in this state for more that a few years already know) can change quite quickly under the right circumstances. And it starting to appear that conditions may be right for some very significant precipitation over the next 10 days.
(NOAA/NWS)
First things first, though: a very cold Arctic airmass has invaded the Pacific Coast of North America over the past few days, bringing snow all the way down to sea level in Washington, Oregon, and even briefly on the beaches of the far north coast of California. The entire state of Washington, and much of Oregon, are expected to receive heavy and possibly record-setting lowland snowfall over the next 3-4 days, with accumulations exceeding 12 inches possible all the way down to sea level near Seattle. While California is unlikely to see any extraordinarily low snow levels this week (outside of the possibility of a few more flurries along the far North Coast early Tuesday morning), a long-duration (and possibly record-setting) deep freeze is already underway across much of NorCal this evening. Temperatures by 11 PM had already dropped into the 22-27 degree range across large parts of the Sacramento Valley and were already below freezing across much of the Bay Area. With dewpoints mostly in the low 10s, record low temperatures are likely across large portions of NorCal on Tuesday as surface temperatures drop into the low to mid 20s in most locations and even as low as 12-17 degrees in the coldest valleys, even near sea level. In short, tomorrow morning will be very cold by NorCal standards, and there will probably be some agricultural damage and perhaps even some burst pipes as a result.
These cold temperature, though, will not last long. By Wednesday, warm and very moist air will initially override and eventually displace the cold and dry Arctic airmass over California as a strong zonal jet–yes, finally, a strong zonal jet!–noses into the far northern part of the state. Rain will begin slowly over far NorCal on Wednesday and spread southward through Thursday, reaching the Monterey Bay Area by late in the day. PWs over 1.5 inches are associated with these incoming systems, and there will be a moderate low-level jet acting to squeeze out some fairly high precipitation rates over the Coast Ranges and the Sierra Nevada. This sort of precipitation will be highly beneficial, since rain rates will not be high enough to cause any flooding problems but accumulations will be rather significant, perhaps on the order of 2-4 inches in the higher elevations, with 1-2 inches elsewhere. A similar storm is expected to arrive by Friday and drop a similar amount of precipitation across NorCal. The first storm probably won’t make too much headway into Southern California, perhaps bringing some light rain, but the second system will probably bring at least some precip to the entire state.
Probably of greater interest is the possible evolution of the pattern days 7-10. The extended forecast models–and the GFS in particular–are showing early indications of what could be a very significant precipitation event on Day 8. It appears that a large and deep cyclone off of the Washington and B.C. coasts may set up a long and deep band of subtropical moisture convergence somewhere along the Pacific Coast. With the presence of a very strong zonal jet (and also a low-level jet enhancement near the coast), this is a setup that has the potential to produce heavy precipitation where the moisture plume hits the coast. The 00z GFS focuses this plume on Central California, bringing very heavy 48-hour precip totals to the Bay Area next Tuesday. This is still over a week out, and very much subject to change, but it ‘s worth keeping an eye on considering the soil-saturating rains expected over the next 7 days over the northern 2/3 of the state.
(NOAA/NCEP)
In any case, one statement can be made with very high certainty: winter is, at last, on our doorstep. Stay tuned.
© 2011 WEATHER WEST
The new run of the ECMWF shows almost no rain for So Cal. Around a half an inch by the end of the run. GFS is trending more dry as well.
yeah we’ll get screwed, then it’ll go back to the crappy cut-off lows & inside sliders and maybe we’ll get a decent storm in march and then that’ll be it, yay winter in socal!
It is not looking good for So. Cal. Rain wise. It is going to be a long dry winter. At least the Central and northern part of the state will get some much needed rain.
I wouldn’t write off this weekend so soon because of the models’ abysmal performance this season. Here is an excerpt from LA/Oxnard WFO AFD from this morning:
LONG TERM (FRI-MON)…IT WILL BE TRICKY TO GET THE DETAILS EXACTLY
RIGHT AS VARIOUS UPPER LEVEL IMPULSES WILL PUSH INTO THE WEST COAST FRI THROUGH THE WEEKEND…AND THE MODELS ARE NOT IN COMPLETE AGREEMENT. IT DOES LOOK AS THOUGH IT WILL RAIN JUST ABOUT EVERYWHERE ACROSS THE FCST AREA AT SOME POINT FRI THROUGH SUN…BUT IT LIKELY WILL NOT RAIN THE WHOLE TIME. MODELS CONTINUE TO FLIP FLOP WITH REGARD TO THE STRENGTH OF EACH IMPULSE AND HOW FAR SOUTH SIGNIFICANT RAIN OCCURS WITH EACH. AT THIS POINT…IT LOOKS AS THOUGH THE BEST CHANCES OF DECENT RAIN WILL BE FRIDAY AFTERNOON THROUGH EARLY SATURDAY…AND AGAIN SAT NIGHT INTO SUNDAY. HOWEVER…THIS IS CERTAINLY SUBJECT TO CHANGE.
However, I do have a feeling that we are in a weather regime similar to the 1998-1999, 1999-2000, and 2001-2002 time period. I am not saying that this is an exact match to these years, as there have been some differences in some areas like the cold in the Pacific NW, but the extraordinary mildness that has been persistent from coast to coast overall most of this fall and early winter season stands out to me as being similar to that those years I mentioned.
Well, we’ll have to see. Recent model runs have been a lot drier for the entire state, though it’s not clear if this is a trend that will be sustained. The problem may be that this isn’t really a sustained long-wave shift–we’ll just be in the path of the “breaking wave” for a little while, so it is possible that we have a few days to a week of rain and then go right back to our extremely stable and dry pattern. Again…let’s hold off on passing judgement for at least a couple more days…
Daniel the 00z is a out liner i would go with the ECW NAM ecmwf ensembles GEM wish have been more consistaint then the gfs
00z has a potential lowland snow event around the first… have noted the same block placement in several runs of the GFS now, and also noted the same placement in the 12z ECMWF. Defiantly will be watching that.
nice to see we won’t have quite the same stable ridge we did for the past few months. Very cold solutions are really not that uncommon in the extended models this time of year, so those are scenarios I take with even less confidence than usual for something 10-14 days out. There is quite a lot of very cold air bottled up over western Canada, though, and there has been for quite some time now, so there is at least the potential for the right flow pattern to move it south…
yep… I was expecting a boring 7 – 14 day on the 00z… I guess I’ve been proven wrong. Really hope the 00z tries to follow this along with following GFS runs. But who knows maybe they’ll switch back to a warm wet extended or a cooler dry one.
Seems like everybody else here got blacked out today too. Is this something all of WordPress did or just Daniel?
Here in Norcal we’re anticipating some good storms the next couple days. The one Friday could be really juicy. I’m also watching the potential for a low snow event around the first. It’s still a ways out but hard not to be interested in it.
It was a protest for a huge Internet Censorship bill.
That was a personal decision to participate in the blackout. SOPA and PIPA are pieces of legislation so poorly conceived that even a small, relatively non-commercial site like this one would be vulnerable to forcible takedown and lawsuits, should they pass as currently written. Generally, though, let’s try to keep the conversation on-topic in the comments…
Thanks for the explanation.
Good for you Daniel! Thanks for taking a stand.
Back to Weatherwest.
First time since 2010 that it might rain on my birthday for Friday. To bad its nothing like the storm that brought 4 inches of rain, hail, lightning, and wind to So Cal. Last year and in 2009 it was near 90 degrees.
Death ride looks like its coming back on GFS.
Recieved 1.5″ of rain so far a trace of snow yesterday am. Interesting the Sacramento river canyon north of redding was closed yesterday due to snow. All I got was rain and I’m 1000′ higher. Go figure? They did have hurricane force winds of southern Oregon coast yesterday. Hardly a breeze here. Oh Daniel thanks for the explanation of the blank screen yesterday, I was afraid some dweeb had hacked the site again.
Looks like the storm is starting to flop out — only predicting 0.25 – 0.33 of rain — not looking good — my area probadly will only get bout 0.10 – 0.17 of rain
This hardly sounds like a long term pattern change. It just looks like a couple of weak systems quickly hitting the area and going back to a dry pattern next week with highs approaching 80 once again. I’m getting sick of this dry pattern that CA has been stuck in recently. I am looking forward to a true pattern change in which a series of storms affects the entire state lasting for at least a week or two bringing a good dose of rain and lower snow levels with only brief dry breaks in between storms like we normally get sometime between January and March.
I feel your pain Dan. Sometimes you got to take that good with the bad. Its looking more likely that this season will be not so good. We can only hope the PDO goes positive and better days will come for So Cal
I do have a feeling this is going to be a drier than normal year, but I don’t think it will be as bad as 2001-02 or 2006-07 since our record driest years don’t seem to happen in La Nina. The total rainfall for Los Angeles this season is already above 2006-07′s total, despite how dry it has been lately. I think L.A. will receive at least 7-8 inches for the season, and possibly more if things pick up in the second half of the winter. A dry January doesn’t necessarily mean that February and/or March will be dry as well, but there is always a slight possibility that each of those two months could be below normal. I have seen slow starts like this before when we have had good rains during that period, such as 1999-2000, and that season L.A. actually had about 11 inches, and the PDO was negative I believe and we were in a stronger La Nina than this year.
It is looking more like a wind event for So. Cal. Mountains and foothills of the desert than a rain event. Big fire burning between Carson City and Reno 3000 plus acres with 10 homes and some business destroyed. winds 80 mph with a gust on slide mountain. 122 mph. headed are way just not much rain. Fire season is going to not be friendly this year.
Looks like NorCal will get one solid rain event tomorrow, and SoCal will get some (for the record, we’re only gotten a trace or so in the Bay Area out of the current one). This is turning out not to be the pattern change we had hoped it would be. While the Sierra will get a couple of feet of badly needed snow in the next 48 hours, this brief respite will still leave us dramatically below average for the season (and even for the month!) in NorCal, and there’s little hope of of additional precipitation after Sunday through the end of the month and even into the beginning of February. It does look like an amplified pattern may be trying to set up in the very long term, but it seems as if we’ll be on the dry side. Stay tuned.
Yeah, no one wants to hear it but it seems ca was overdue for a dry year and here it is.
I just miss sculpting my driveway
http://www.flickr.com/photos/23887317@N08/5483771256/in/photostream
This was the 2-27-11, so there’s still hope for feb/march, i just want one big cold storm down here!
ECMWF continues its cold trend late in the month… while the GFS, as ussual, indicates the giant death ridge. The GFS will be recieving a upgrade on the 24th, which will increase it’s resolution and update its physics. I will not be following any GFS runs until its been updated, just seems to unstable to me.
The front looks kind of poor coming this way. I smell a shaft.
Shaft smelling sounds unpleasant.
When I’m in ca next week I wouldn’t mind seeing some rain but I’ll enjoy the warmth too.
It always rains when I go back to work.
San Diego calling for 50% chance tonight and 90% for the morning drive up to San Pedro tomorrow with around a quarter to a third of an inch. Hell I’ll take it ! Better than nothing.
Really pouring up here tonight in Siskiyou county with snow above 4000′. Next storm on Sunday is supposed to have lower snow levels. Hear that mount Shasta ski park will finally open for the season tomorrow. Yeah Ken I agree that our fire season could be busy this year.
Pretty good rain in the Bay Area tonight, too. Actually, this is the first time since April 2011 I’ve actually heard rain falling on the roof! Might even be some lightning in the frontal band–really starting to light up on radar. Anyway…things dry out again pretty quickly by Monday. As some have noted, though, ECMWF and GFS are hugely divergent in the 7+ day forecast. The GFS rebuilds a fairly deathly looking ridge over the West Coast, but the ECMWF has consistently been indicating that a deep and very cold trough will set up just off the West Coast and bring some potentially very cold and unsettled weather days 8/9 and beyond. It’ll be a waiting game to see which scenario wins out…
This storm is definitely living up to its billing here in Norcal. The main event will be swinging through over the next several hours bringing some minor flooding and the strongest winds. Some of the flooding might be threatening some property in the area as these rain bands seem to be getting stronger. There are already power outages showing up in my part of town so my house might be going dark soon.
Wow, this rain is really getting crazy. I think there’s going to be a lot more flooding in the area than I thought. It’s gonna be a wild night.
Have picked up 4.40″ so far. Orographics will likely keep precip going most of the night here. Will post storm total tomorrow.
Good to see the Northern part of the state picking up some rain and snow. Way over do. I hope the ECMWF comes through. Of course here S.D. County showing mid 80′s on Wednesday. This crazy warm weather has the fruit trees messed up, another year of not much fruit. You folks up north enjoy the weather, hopefully the front will hold together for us. Tom enjoy your trip.
Thanks Ken, just now starting to drizzle as I’m making a few last emails. Hopefully between today and Tuesday San Diego will get enough to take us back into the green for season %-age of normal. Glad to hear the folks up North finally getting some.
Remember, this IS a La Nina year, below normal and weird patterns are kinda to be expected.
Ahhhh… the 00z ECMWF dropped the arctic blast. Hopefully it doesn’t continue that with the 12z run.
I was actually surprised to see Eureka & Crescent City both had record daily precip @ 2.20″ or so, and several 72hr rain totals 6″ to 11″ in mostly very northwestern cali, been misty/light rain in Santa Maria for a few hours now, looks like the front is starting to move through.
Twain Harte, CA has pick up 4.57″ of rain we have not had a storm like this for a long time
If the 12z was right that would have to be one of the strongest Winter time ridges in history. 1035 is quite impressive.
Storm total here is 4.66″
As of 10:50am 1/21/12 Redlands, Ca has 0.26 of rain — bit more than i predicted — hopefully we get more rain — no high winds here — please no death ridges like Nick is talking bout —- Be nice to get real cold temps and a bit of snow —
We had some very good rain last night. Some of the local creeks came close to flood stage but didn’t go over, as far as I know. Not having had rain for a while helped in this regard. Like everybody else, I’m hoping the ridge from hell doesn’t set up again. The snow level was over 7,000 feet last night during the meat of the storm and it didn’t start to lower until this morning. Snow totals from this series of storms won’t be too impressive so we definitely can’t afford to have another long snow drought.
We had 0.60 of rain here in Whittier. Not a bad day NWS even had thunder in the forecast this morning. Not sure if there was any action as the radar was down.
According to San Diego’s latest AFD, it appears that Monday’s storm may be stronger and wetter than this last storm. That is definitely an improvement from the outlook the other day. They also mentioned the possibility of next week’s ridge breaking down toward the weekend for cooler weather. Let’s hope it breaks down even more to allow more storminess into the area, which would certainly be nice.
In 45 hours according to Plymouth State Models it shows best chance for T-storms for Whittier/Fullerton area in 45 hours…
Precipitable water: 0.76 inches
Conv temperature: 13.34 C = 56.02 F
Lifted Index: 8.74 C Risk: None
Lifted Index @300 mb: 13.41 C
Lifted Index @700 mb: 2.16 C
K Index: 21.79 Risk: 20-40 % chance of thunderstorms
Sweat Index: 158.26 Risk: None
.64″ fell here in Orange with today’s storm, which is actually about double of what I expected based on the forecasts. I’ll take it! The next storm is forecast to possibly be wetter and I hope that this forecast verifies.
It appears like Redlands, Ca got the shaft — rain-wise —- by looking at the above post — hopefully the next storm will deliver more rain for Redlands—-
Redlands, How much rain did you get with this last one?
Dan — the storm on Jan-21 — my station in Redlands, Ca only got 0.26 of rain —
Redlands, you were not the only one to get the shaft. We picked up .16 at the house, enough to get the ground wet and that is about it. The next storm is already starting to drop the rainfall amounts, so another repeat of Saturday. At least it is a colder system, get some snow in the mountains.
Received about 3″ of snow this morning, then it let up this afternoon so I plowed the compound at our conservation camp. Got it all down and now the snow is really coming down. NOAA Medford has predicted that we will be in a zonal flow pattern until thursday then maybe the ridge will move back in for a dry weekend. GO Niners!!!
Yes — I’ve noticed that they were predicting a certain amout — then it went up — now they have lowered it —- guess it depends on where u get the info from — hopefully this next storm will prevent my station from being the driest ive recorded since Aug 1981 —-
Looks like as of 930am 1-23-12 — this storm is gonna be a big flop storm — only 0.02 of rain — such a disappointment
Twain Harte, CA have pick up 6.97″ of rain from sat too monday
6.24″ on the coast of California at Little River.
this is Friday AM through Monday AM.
we need MORE!
Mendo
Mendodave, welcome to the blog!
I agree with you that we need more rain and mountain snow, and that is for the entire state. I don’t like the fact that much of CA is returning to a dry pattern later this week and hopefully it doesn’t last very long, either.
Twain Harte, CA have ended up with 7.01″ of rain from sat too monday
0.66 of rain today. Not to bad rain with moderate at times
The storm on Jan-21-12 — only 0.26 — Storm today — 1-23-12 only 0.24 in Redlandsd, Ca — from above Redlands again got the shaft — I dont like that its gonna heat up to the 80′s in a few days. Well – at least this Rain-Season 2011-2012 wont go down as the driest I’ve recorded which occurred in the 2001-2002 season when i only recorded 2.78 !!!! Right now this season is the 2nd Driest ive recorded — the rate we are going in my area i dont think its gonna get much better — might end up as 3rd driest
.45″ fell here in Orange from yesterday’s storm, which was less than what fell here on Saturday.
SB mountains (west end) got about 1″ of rain over the weekend, yesterday a couple inches of wet snow in the late afternoon.
West coast looks interesting the first week in feb, hoping socal is able to get in on the action…..