The “non-winter” of 2011-2012 continues

As has been case for the entirety of the traditional “wet season” thus far, California continues to experience very dry conditions. Though the length of absolutely dry periods has decreased in recent weeks, the dry spells have been punctuated only by brief periods of light or very light precipitation (with a couple of highly localized exceptions). Cumulative precipitation totals for the water year, winter season, past month, and–despite some recent precipitation–even for the past week are all well below normal across nearly the entire state (and, for that matter, across most of the Southwestern U.S.). In fact, the most recent update from NWS/CPC indicates that most of California (and Nevada, and Utah, and Arizona) has received less than half of typical precipitation so far this winter, and over a third of the state has received less than 25% of average during the three months that usually make up the peak of the rainy season in our region.

The wide geographic scope of the very dry conditions across the Western United States is indicative of the type of prevailing weather pattern that has led to the present situation: rather than a long train of “near-misses,” whereby numerous storm systems miss California either to the north (bringing copious rains to the Pacific Northwest) or to the east (in the form of “inside sliders,” bringing widespread rain and snow to the interior West), there has been a remarkable dearth of storm activity across the entire Western third of the country. The most immediate cause of this impressive dryness has been the persistence of an anomalous ridge over the Northeastern Pacific for essentially the entire winter.

Teleconnections between California wintertime precipitation and tropical convection in the Western Pacific are well-known, and on intra-seasonal timescales the Madden-Julian Oscillation tends to be a good indicator of the potential linkage at a given point in time. This winter, the MJO has been very quiet–regions of suppressed/enhanced tropical convective activity have been small and longitudinally stationary. Such behavior is not particularly unusual during a La Nina event, but there are usually some other aspects to the hemispheric pattern during Eastern Pacific cold events that usually bring at least modest (often cold) precipitation to much of the American West. This year, we haven’t really had any amplified meridional flow over the U.S., which has prevented the kind of sub-polar incursions that might otherwise have boosted our presently meager precipitation totals.

The all-important question, of course, is whether we might finally receive some late-season precipitation that could at least mitigate the effects of the very dry season thus far. While I see little hope of significant precipitation anywhere in California through the end of February, there are some recent changes in large-scale conditions worth considering. In the past 1-2 weeks, a rather strong MJO signal has emerged in the Western Pacific and is slowly propagating eastward. The first question is whether this signal can hold itself together and continue to propagate into a position favorable for forcing an amplified Pacific jet stream. The second question, of course, is whether we would even see any rainfall out of a strengthened zonal jet given the magnitude of the entrenched Pacific ridge. Only time will tell on this front, though it’s worth paying attention to the large-scale pattern in the 2-3 week range.

Secondly, La Nina appears to rapidly be on its way out of the picture. SST anomalies in the traditional Nino 3/Nino 4 regions have actually gone positive in the last few weeks, and there’s even a subsurface pool of warm water around ~300 m. In addition, there are presently strong westerly wind anomalies in the Eastern Pacific, which will only contribute to additional surface warming. While this is probably a positive development with respect to long-term rain prospects, it’s unclear if the transition to ENSO-neutral conditions will occur soon enough to have a significant impact on water year 2011-2012. It’s still too early to be talking seriously about El Nino prospects, though I will say that some of the dynamical models are indicating positive SST anomalies by mid-summer.

As always…stay tuned.

© 2011 WEATHER WEST

  • Dan the Weatherman

    This year is reminding me a lot of the 2001-2002 season with the lack of high-latitude blocking, lack of rain in Socal, and the incredibly mild conditions that the majority of the U.S. has experienced since the fall. However, I do believe that Norcal was much closer to normal in terms of rainfall, unlike the extreme dryness of this year.

    • sc100

      Norcal was a little below average in 2001-2002. I remember the huge rain bust Socal had that season. Pretty crazy stuff. What’s crazy this year is that the entire West Coast has been drier than normal, well up into British Columbia. There’s just very little activity going on in the Pacific. A lot of weak storms. Let’s hope that MJO does something for us.

  • Nicholas

    This winter makes me want to throw up.

    Here is the best of the best…

    October 5th 0.62 inches of rain
    November 20th 0.64 inches of rain
    December 12th 0.54 inches of rain
    January 23rd 0.62 inches of rain
    February 15th 0.24 inches of rain

    • sc100

      Ditto that. This has definitely been the most brutal winter of my lifetime here in Norcal. We’ve had seasons that started off as dry as this one did, like 1999-2000, but had good rains come by Jan or Feb. Not so this year. It’s very rare to have annual rainfall in Sacramento of less than 10 inches (hasn’t happened since 1976-1977) but there’s a good chance it’ll happen this year, as we currently stand at 5.68″.

      • Dan the Weatherman

        You are absolutely right. Oftentimes we have had seasons start out dry and then turn wetter later on such as in February or so, even if the annual total is somewhat below average. This is one of the main reasons I have repeatedly been forecasting a change in the overall pattern during the last month or two. It is rare to go through the entire season as bone dry as this, particularly for Norcal, and is indicative that a very unusual set of circumstances or factors are in play that is keeping this eastern Pacific ridge more dominant than normal and blocking the state from getting any large meaningful storms.

  • PacificStorm

    AREA FORECAST DISCUSSION
    NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
    253 PM PST WED FEB 22 2012

    IN THE EXTENDED…STILL NO SIGN OF A MAJOR STORM IMPACTING OUR
    AREA. ECMWF DOES HAVE THE SOUTHERN EXTENT OF MOISTURE FROM A PACNW
    SYSTEM GOING ACROSS THE NORTHERN HALF OF THE CWA ON WEDNESDAY. GFS
    KEEPS MUCH MORE OF THE ACTIVITY TO THE NORTH WITH JUST A GLANCING
    BLOW HERE. AFTER THAT THE REST OF THE NEXT WEEK LOOKS QUIET.

    FOR THOSE WANTING ACTIVE WEATHER THERE MAY BE SOME RELIEF IN THE
    VERY FAR EXTENDED AS THE MJO TRANSITIONS FROM PHASE 2 TO 3 WHILE
    MORE OF THE ENSEMBLES (PLUS THE ENSEMBLE MEAN) BRINGS THE MAIN
    STORM TRACK CLOSER TO SF/MONTEREY BAY. EVEN THE 8-14 DAY OUTLOOK
    NOW HAS NORMAL RAINFALL FOR THE CWA WITH ABOVE NORMAL JUST TO OUR
    NORTH. FAR TOO EARLY TO GET EXCITED ABOUT RAINFALL POTENTIAL WAY
    OUT IN THE SECOND WEEK OF MARCH…BUT IT IS WORTH KEEPING AN EYE
    ON.

  • Nicholas

    No words to describe how poor the past few model runs have been today. I just hope summer comes and goes quick and we can forget about the winter that never was.

  • coldspot

    Warm day in Redding today but quiet windy. Shasta lake is pretty low for this time of year. Looks like we might get some light rain and then light snow for this weekend. Have to wait and see.

  • PacificStorm

    hmmmm… cold air could get trapped tuesday night/wednesday as that cold front comes through… maybe some snow around 2000ft?

  • PacificStorm

    Becoming increasingly likely that I could see 12 – 16″ of snow here Tuesday night/Wednesday… some of the recent models have indicated even more! The most I’ve ever seen since I’ve lived here is about 10 – 12″… would be nice to break that.

  • Ken K.

    Monday is looking like an interesting day with Snow levels dropping down to 2500 Feet in So. Cal. Winter Storm Watch posted for above 4000 FT. Looks windy as well.

    • redlands

      Ken — Where u from ???? Myself am not gonna get too excited — In my area – the Redlands, Ca area — the most rain i expect to get is 0.15 —

  • Dan the Weatherman

    Tonight’s San Diego WFO AFD has some odd wording that doesn’t quite fit the weather pattern as of late:

    Excerpt # 1: “THIS SYSTEM WILL ALSO BRING ANOTHER ROUND OF RAIN AND MOUNTAIN SNOW TO THE REGION…STARTING LATE SUNDAY NIGHT AND SPREADING ACROSS THE REGION ON DURING THE DAY ON MONDAY.”

    Another round of rain? Huh? We have only had one storm this entire month with measurable rainfall (and very light for a mid-winter storm at that).

    Excerpt #2: “ANOTHER TROUGH WILL THEN MOVE ACROSS NORTHERN CALIFORNIA ON WEDNESDAY. MODELS ARE NOW HINTING THAT SOUTHERN CALIFORNIA MAY SEE SOME LIGHT SHOWERS LATE WEDNESDAY NIGHT AND THURSDAY…BUT THE MOISTURE LOOKS
    QUITE LIMITED AND WOULD LIKELY BE LIMITED TO AREAS ALONG AND WEST OF THE MOUNTAINS. A GRADUAL WARMING AND DRYING TREND WILL FINALLY BEGIN TO DEVELOP OVER THE REGION FOR REMAINDER OF THE WORK WEEK AND THE FIRST PART OF THE WEEKEND.”

    A gradual warming and drying trend will finally begin to develop…? Say what? We don’t need another warm dry spell anytime soon as we need as much rain as we can possibly get before the dry season sets in later in the spring. The way that this discussion is worded makes it sound as if it has been a very wet winter and that we are in need of a dry period, or at least that is how it sounds to me.

  • http://www.wunderground.com/blog/Inyo/show.html Inyo

    Yeah, I’ve seen NWS do that a few times. Say “unfortunately” about a storm during a very dry year. It’s tv weatherman amateurism and luckily is rare in NWS but not absent. I even emailed them about it once but the response seemed to indicate that they still didn’t get it.

    Not that disliking rain during droughts stops the storm. It just makes them look like they don’t know what they are talking about. Maybe it’s new forecasters from other areas or something.

  • Tom in San Diego

    Don’t get me started about TV weather.

    “Rain, Rain, go away, little Tommy wants to play”
    Just another example of media slant and bias; sunny weather = good news,
    rainy weather= bad news. that’s the line and with rare exception they all dutifully march along behind it. Used to be worse, 30 years ago, the weather guy was comic relief on many stations.
    In San Diego they still do the shtick that the weather guy or gal has to actually be right out there in it. So they send them on remote someplace dressed like the fisherman on a Gorton’s frozen seafood box to stand in drizzle and report on the “Big storm”. They look silly. That or “when will this rain ever end!!” before the main body even gets here!

    Underway from Yoko, Friday expect to in San Pedro next Monday, we’ll try and can bring some westpac rain with us..

    • redlands

      Tom – I 100% agree with u — Rain is bad — Sunny- No Rain is good —- It has rained a few drops and there asking when will it end — Oh my !!!! Just enjoy it — We dont get rain that much here in Southern California. — It also bothers me when people say it gets cold or its really cold in Southern Calif — there are a few exceptions – higher mountains – maybe deserts but this area doesnt really get cold like other areas of the country. — We really are spoiled living in Southern California – overall its pretty bland — Well thats how I feel for my area — the Redlands, Ca area

  • coldspot

    Looks like a “real winter storm” is finally shaping up for the north state this coming tues/weds. Noaa Medford discussion indicating descent snow amounts for that time frame. Sure did not get diddly squat out of the fri/ sat event, 11 hundreths of precip at the house. But it was blustry and cold yesterday. Unfourtunatly sounds that the ridge will re-establish itself this coming weekend.

  • PacificStorm

    NAM is continuing to indicate 12 – 18″ of snow here in the Butte county foothills… a few runs have indicated up too 2ft!

  • Shady Blues

    Yet again, San Diego is going to get hit the hardest…

  • http://weatherwest.com Daniel Swain

    Looks like yet another system is bypassing the Bay Area almost entirely. Could get some isolated convective stuff this PM given how steep lapse rates are today, I suppose, but SoCal will certainly get the brunt of whatever this low can muster. The Wednesday system looks more promising for at least a wetting rain (and perhaps a significant modestly-low-snow-level event), but it’s by no means a drought buster. Looks like even the bonus of a leap year system will STILL leave us well below average for the month, the water year, and etc….

  • redlands

    When is the storm gonna arrive ??? Its 11:18am – no rain — temp is 55.7 — gust to 14 mph – pressure is 29.84 — i dont think its gonna be as cold as they were predicting —- is the storm doing the flop-thing again

  • redlands

    Its up to 61 in Redlands, Ca as of 111pm 2/27/12 —- no rain — just clouds and wind gust to 14mph — disappointing

  • alan

    It’s not acting like last weeks storm that took a similar path, no action ahead of the front, dying winds, and honestly it looks like the bulk of it is sliding past offshore and hitting san diego county….we’ll see what we get redlands, just a dusting of snow up the hill and here in rancho cuc. we’ve had a few hundredths mostly before 9am and trace amounts since then…. NWS still holding on to there 6″ to 10″ above 5500′ and winter storm warning ending @ 10pm tonight, i just don’t see it…..

  • Dan the Weatherman

    It began raining here in Orange just after 1 p.m. and has been moderate to somewhat heavy at times and I even heard a clap of thunder a little while ago. It is still raining lightly as I type as it has lightened up in the last few minutes.

    It’s certainly nice to see it raining here for a change, as it has been like pulling teeth to get it to rain here this season. This season has certainly reminded me a lot of the 2001-2002 season except that Norcal was wetter that year.

    • Dan the Weatherman

      Another band of rain is approaching my area from the SW, so I believe that Orange will continue to see some more significant shower activity as the day wears on. Redlands and Alan, I hope you both get something out of this one!

      • Dan the Weatherman

        The rain has just begun picking up in intensity and is now coming down moderately once again. I will post more on the storm later and post a total when it winds down later tonight or tomorrow.

  • redlands

    Its still a flop in Redlands, Ca at 208pm — temp has gone down to 55 — pressure 29.78 and falling – no measureable rain –

  • Nicholas

    Saw a bit of lightning just a few moments ago here in Whittier. It got real windy as well.

  • redlands

    Down to 51.6 at 303pm in Redlands, Ca — no rain

  • alan

    well i guess there’s a couple inches snow in my neighborhood now…

  • redlands

    At 424pm its 44.2 in Redlands,Ca — we have 0.07 of rain — looks like the majority of storm is going to San Diego area — temp is dropping decreasing at -4.56 per hour — as i write this temp keeps falling –

  • redlands

    Its 39.3 at 717pm in Redlands, Ca — 2/27/12 — so close to it snowing — 0.31 so far in rain

  • PacificStorm

    still looking like a pretty good low snow event up here north of I-80… I’m at 2500′ and it currently looks like I could see 14″ Tuesday/Wednesday and maybe another 2 – 5″ Thursday on top of that.

  • Nicholas

    Getting more lightning/hail tonight here in Whittier. I have been one of the more lucky ones today in LA County. That cell looks to be working towards Orange County.

  • Dan the Weatherman

    Still getting some off and on light to moderate shower activity here in Orange in a W / WNW flow pattern. It certainly is much colder tonight than it has been for a while as it is currently about 46 degrees.

    • Dan the Weatherman

      I almost thought I heard a bit of thunder here a couple of minutes ago, but it may have been a neighbor moving something outside, because the sound didn’t continue on long enough.

  • sc100

    It’s a relief to finally see a real winter “storm” develop, with strong winds, low snow and heavy precip. It’s incredible Norcal had to wait until the last week of February to see one! The storms we saw that one week in January were warm ones. And of course we basically had zero precip in December. The storm slated for early next week is looking real nice right now as well. It looks like it could be bigger than the one coming over the next several days with even colder air.

  • Ken K.

    We have picked up .40 so far at the house (Granite Hills) had a good Thunderstorm move through just after 8 PM with hail and lighting. Still getting showers and wind.
    Redlands I am in the foothills of SD county SE of El Cajon.

  • alan

    10″ snow, snow valley another 1000′ up reporting 13″ to 15″, not too bad! 1″ of snow all the way down @ 2000′, beautiful sunrise! Still no multi-foot snow storm this winter and we’re at just under half our yearly average for socal mountains…

  • alan

    although the san diego mountains might be pretty close to average….

  • redlands

    Stats — Redlands, Ca 61- 38 Rainfall 0.35 wind gust of 17 mph — for the month 0.80 for the 2011-12 rain season – 3.73 — was so close to snowing — only if it was a bit colder

  • http://weatherwest.com Daniel Swain

    Not a drop up here in NorCal from that last one. That should change, tomorrow, though…

  • PacificStorm

    Thinking I could see 8 – 12″ still, and it it snows for the entire storm besides maybe the first hour, which is possible, I could potentially see 14 – 18″. Another 3 – 6″ possible Wednesday night into Thursday. Could have a pretty deep snow depth come Thursday morning! Severe thunderstorm warning on the southern OR coast right now for very strong winds, gusting to over 70mph in some cases. Wouldn’t doubt seeing some valley/foothill thunderstorms Wednesday afternoon as the decent cold pool comes overhead.

  • PacificStorm

    Wouldn’t doubt there could be some waterspouts along the N CA/S OR coast this evening with that line of convection.

  • Dan the Weatherman

    .54″ fell here in Orange with this last storm and was more than I expected, given the nature of the storms so far this month. This area received more rain than most of the Orange County stations, and much more than downtown Los Angeles or LAX. San Diego County received the brunt of this storm with amounts ranging from just under .4″ to over .75″.

  • http://weatherwest.com Daniel Swain

    Severe thunder-snow-storms right now over the far southern Oregon and far Northern California coasts. Pretty interesting. Will need to keep an eye on these convective bands perhaps as far south as the Bay Area later tonight…

    This storm will probably be most remarkable for those living between 1000-2500 feet, since some very substantial snow may fall at elevations not at all used to it. This is NOT a sea-level snow event, but 6-15 inches of snow at 1500-2000 feet elevation in California is definitely not something that happens very often…

  • PacificStorm

    Been more of a sleet storm here at 2500′ in Butte county… 33 degrees but still mixes with rain at times. Hopefully it switches over soon… or at least drops below freezing to maybe get some freezing rain.

  • PacificStorm

    2 – 3″ of sleet fell overnight, another hail storm earlier this evening. May see a little more snow tonight as that 130kt jet streak intensifies that weak shortwave off the coast.

  • coldspot

    Received about 4″ Tuesday night Wednesday morning then picked up 5″ last night. Interesting to get more precip in the post frontal showers then the main front. Actually this is the most snow on the ground here in the last two and a half winters. Lots of precip last year but the snow level was always about 1000′ above us.

  • PacificStorm

    Looks like this month will be much more active compared to any other months this season.

    • sc100

      These long range models have been teasing us for a while but I think they’ll start giving us the goods this time. At least that’s what I’m hoping!

      • Dan the Weatherman

        I agree with you as I believe CA, especially Norcal, is due for a good dousing of rain and snow. Norcal has experienced a dry winter that rivals Socal’s driest years so far this season and that needs to change!

  • http://weatherwest.com Daniel Swain

    Looks like that possible shift I mentioned two weeks ago might finally bear some fruit next week into the middle of the month. Fingers crossed…

  • PacificStorm

    GFS ensembles look good, ECWMF is bleeh.

  • http://weatherwest.com Daniel Swain

    Pattern change potential still there, but iffy.

    It’s too late to affect this water year, but East Pac SSTs have been warming very rapidly over the past few weeks. In fact…fairly large positive anomalies have already replaced modest negative anomalies at the start of the calendar year. Hard to say at this point if this is just the product of a short-term westerly wind burst or what, but if the present strongly positive westerly wind/SST anomalies maintain themselves for any length of time, next winter could be interesting.

  • Dan the Weatherman

    I do not like what I have seen in the weather this week and what it may mean for the rest of the spring. First of all, we had a tragic tornado outbreak yesterday with many deaths that covered a very large region of the eastern U.S. and very far north for so early in the season that is more reminiscent of an outbreak that would happen in April or May. Secondly, it has warmed up substantially here in Socal and this warm and dry Santa Ana wind pattern looks to continue off and on for the next week with the exception some brief cooling and possibly a shower or two midweek. What I am worried about is twofold: another repeat of last spring with large scale severe weather and tornado outbreaks leading to more death and destruction than normal for the eastern half of the country coupled with a dry and hotter than normal spring for CA if this Santa Ana pattern continues well into April with possibly some unseasonable brush fire activity. (Last spring was pretty nice in Socal, but definitely not the case back east.) If this pattern continues I expect spikes of temperatures into the 90s or even 100 for brief periods in April and May much like 2004 and 2008 here in coastal and inland coastal Socal.

    I am really hoping for a pattern change that will bring us some beneficial rain later this month and hopefully a bit of a shift in the pattern to tone down the severe weather potential back east. I know I am asking for a lot here, though.

  • Dan the Weatherman

    SFO WFO discussion from this afternoon is still indicating a possible pattern change to wet weather for mid March as the MJO has now moved into phase 3 and the models are indicating rain possibilities for that period. If this comes to pass, it will probably be one of the largest and most beneficial of storms or series of storms for the entire season for the state and may also help to prevent the high April heat I am forecasting if the current pattern doesn’t change.

  • Ken K.

    Dan, I think your warm to hot weather is already here, currently 88 and 13 % at the house and climbing. Of note The South OPS Weather folks are predicting a Warmer that than normal Spring with below normal rainfall and above normal chance for large fire activity. I hope the weather pattern change come with some rain. I sure some spots will be over 90 today, like Redlands area.

    • Dan the Weatherman

      I think you’re right, Ken. It is currently 87 here in Orange and some stations around the region have topped 90. At 3 p.m. Santa Ana is 90, Anaheim is 91, and Fullerton Airport is 94, which almost sounds too hot, and other areas of inland O.C. are mostly in the 80s. If this pattern of upper ridge + Santa Ana condition continues into April and early May with the ever increasing sun angle and longer days, it will be absolutely blazing hot at times with temperatures in the 90s or even low 100s. However, the NWS, especially in San Francisco, is still indicating that the models are agreeing on a pattern change after next weekend that could have a trough in the NE Pacific providing CA with some much needed precipitation the following week. Even the San Diego WFO mentioned this yesterday.

      • redlands

        Ken and Dan — Redlands Ca got up to 87 on my weather station – for 3-4-12 sunday — Although at bout 445pm our Downtown bank thermometer was reading 91 — would be curious to see what our local paper – Redlands Daily Facts – who has kept records since 1920 – recorded for a high on 3-4-12 —– Any way — 88 is too warm for March –although ive recorded a 100 in March — i want cold – rainy-snowy – windy weather

  • Nicholas

    92 today in Whittier. Might just take a vacation till next fall at this rate.

  • redlands

    Was 86 today in Redlands, Ca — 3-5-12 — i think it would of gotten a bit warmer if it werent for the cirrus clouds — The 86 ties a record for the day 3-5-12 at my station

  • alan

    for a minute there the other day it looked like a repeat of last week with several inches of snow for our socal mountains, now we’re lookin’ at a couple inches tops, but some killer winds… long range only showing one or two storms that could still potentially be big for socal mid march, not likely though lol, and then 2nd half of the month is depressing….sigh…. at least norcal looks to get a good soaking

  • redlands

    Redlands, Ca got 0.01 of rain for Tuesday 3-6-12 — wind gust to 13 mph —– Got up to 65 – with a low of 41 for 3-7-12 — At least March wont go dry –

  • alan

    2″ snow/grauple and temps plunged overnight from 32F last night to 15F this morning, strong wind gusts along with it brrrrrr…. roads can officially be ice skated on

  • Dan the Weatherman

    Is it just me or has there been a tremendous lack of variability in the weather pattern this winter? It seems that CA has been stuck in almost the exact same weather regime since just before Christmas, with inside sliders alternating with Santa Anas with the occasional outside slider.

    • Nicholas

      Its been mind numbingly boring weather dan. I bet April will have more of the same.

      • Dan the Weatherman

        Well said, Nicholas. There is a possibility that El Nino may develop later this summer so that should help make next year much more interesting Even if we had another La Nina winter next year, I don’t think it would be as dull as this year has been. After looking at L.A. weather records, I feel that that the area has had its quota of sub 6 inch total rainfall winters in the last decade to last for the next 20-30 years or so. That doesn’t mean we won’t have some drier than normal winter years ahead, but I think at least they will be wetter than 6-7 inches for the L.A. region, unlike this year, 2001-02, and 2006-07.

        • Dan the Weatherman

          To clarify my point a bit better here, most drier than average years bring between 7 and 10 inches of rain to the Los Angeles area, as opposed to between 3.5 to 7 inches. Prior to this last decade, the only sub 7 inch years for L.A. on record have been 1898-99, 1923-24, 1958-59, and 1960-61. We are on the verge of having 3 of these type years in one decade if this year doesn’t produce much more rain, where only 4 have occurred in the last 100 years!

          • Tom in San Diego

            Dan, without looking at the records, SoCal has generally been in a drought period since 1987, with a few exceptions; 1989-90, 92, 97, 03-04, 08, if memory serves.

            FWIW, This last voyage from Japan, rain followed us nearly the entire track, until we turned southeast at Long. 150 last Thursday Friday. (?)

          • sc100

            I remember reading over the years about scientists finding evidence of Mega Droughts in California’s prehistory, periods of low to very low rainfall that sometimes lasted over 100 years. Some have speculated that such a similar period will probably happen again in California at some point in the future. So it could be that SoCal is moving into such a period. Here in NorCal, we had a 20-year period between 1914 to 1934 where every year had below average rainfall.

  • Dan the Weatherman

    I certainly hope that we aren’t heading into a drought era like that anytime soon, because I would begin to dislike Socal if dry winters like this (less than 6-7 inches for the area) became the norm and I would probably want to relocate somewhere up north just to get back into a somewhat wetter climate if possible.

    We would also be facing major water supply issues as well if a drought pattern of that magnitude did set in, especially if the Sierras began to receive significantly less snowfall per season on a regular basis.

  • alan

    a 100 year, 50 year, 20 year, even a solid 10 year drought with winters like this would lead to serious water issues that we have yet to face with this gowing population in socal, ouch don’t even want to think of it!

    On the other hand, does the GFS enjoy torturing us? A couple whopper storms around the 21st or so, looks oh so sweet yet too far away

  • PacificStorm

    Still looks like by next week things turn much more active for at least a week or two… us here in the northern part of the state could see a decent amount of rain next week!

  • Dan the Weatherman

    I believe our dry pattern this year has everything to do with the exceptionally mild weather pattern in much of the continental U.S. this winter. The major indices, the PNA, AO, and NAO have all been predominantly positive for much of this season, keeping the jet stream too far north. The positive AO has in part prevented high latitude blocking from occurring this fall and winter season, and I also believe that the higher solar activity since fall has also been partially responsible for the lack of high latitude blocking. Therefore, the jet stream pattern has not been meridional this year, unlike the last couple of winters. So without the cold storms from the Gulf of Alaska in a meridional flow, the lack of MJO influence, and the lack of a subtropical jet in the immediate area, it looks as if we have been left in the dust in almost every way conceivable this year.

  • http://www.wunderground.com/blog/Inyo/show.html Inyo

    There are mega-droughts in the distant past, and there will be one in the area again… someday.

    however, I don’t really see evidence that most of socal is in an extended drought right now. There have been several dry years but also several extremely wet years including the wettest/second wettest on record in many areas, 04-05. Looking back at old pre-NPS writings, there was another period in the mid to late 1800s where extremely wet and dry years both occurred. I think we’re in a very changable weather pattern rather than a dry one.

    To put things in another way – the wet years are so wet, and skew the average so heavily, that most years have to be drier than average by definition, just to meet that average. 04-05 got nearly 40 inches of rain in some places – if average rainfall is around 15 inches in these places, you’d have to have -10 inches of rain the next year to equal this average out, which of course is not possible… or, have several dry years.

    Long- and short-term climactic changes are certainly affecting so-cal but i am skeptical of an overall long-term drought. Most of our water shortages exist because we are stupid about water. Go look at a hillside during a dry year, then go look at any suburban neighborhood in LA and think about where the water is all going… hint: it is not supposed to be green in August except in the canopies of coast live oaks and a few chaparral plants.

  • PacificStorm

    00z GFS came in very wet next week, with almost consistent rain up here in the northern part of the state from Monday through Friday and even into Saturday… with more storms behind that!

    • Dan the Weatherman

      I hope that some of that rain can make its way into Socal as well. At least Norcal will get some significant rain and mountain snow out of this pattern, and that will certainly help the Sierra snow pack to at least some extent.

    • http://weatherwest.com Daniel Swain

      It certainly looks like it’ll rain next week in the northern half of the state, which is more than I’ve been able to say about most of this winter. There may even be some heavy rainfall, especially up near the Oregon border. I don’t necessarily see this bringing widespread heavy rainfall, though, even in NorCal. There will be a pretty moist plume in place, but I’m not convinced any of the storms are going to be strong enough to squeeze out a whole lot of precip. Also…the persistence of the pattern beyond day 10 is pretty tenuous right now. Not to be overly pessimistic–a widespread cumulative inch or two will certainly be very beneficial this year–but unless this pattern shift holds on for longer than is currently being indicated by the long range ensembles, this could really be our last shot at significant precip this water year. We’ll see!

    • sc100

      Nice to see a whole week of rain coming up. I’m definitely going to enjoy it while it lasts as we all know the dry season is just around the corner.

  • sc100

    NWS is pretty bullish on these storms for NorCal next week, talking about 3-6 inches for interior NorCal with orographically enhanced areas getting maybe over 10 inches. PacificStorm, it looks like there’s a reasonable chance you could get a foot of rain next week. We’ll obviously have to see where the storms later next week line up. Unfortunately, it looks like you guys in SoCal are going to get hosed, though.

    • Dan the Weatherman

      It is looking somewhat more likely that we may get some rain down here in Socal by next Friday-Saturday and Dallas Raines said this evening that it could be our biggest storm of the season. At least you are going to get wet in Norcal for much of this week along with much needed snowfall. You have been absolutely overdue for a wet period up there and I was wondering when it would finally occur, because it is very abnormal for Norcal to be this dry all winter long.

    • PacificStorm

      Sure looks like it… though I’ll be moving down the hill over the next couple weeks, from 2500 too 500′, but will still be on the southwest facing slopes so should still see some slightly enhanced precip.

  • alan

    Models have been consistent with rain starting and lasting through the week in norcal. I bet it opens the door for a couple storms to hit socal after next weekend, you know, the ones that have been popping up in the long range GFS for awhile now, that i thought would hit beginning of march :D i’m not losing faith yet hehe

    • Dan the Weatherman

      I’m not losing faith yet, either, because it feels like we have been in the same fall-like pattern since mid December and it is rare for the pattern to go this long into the winter without changing. We are due for a back-ended rainy season, anyway, since recent years have tended to be wetter in the fall until about February, and drier than normal in March and April.

  • redlands

    I myself wouldnt get too excited — this whole season has been a flop after another flop — its almost mid-March – season is like 95% over –

  • http://weatherwest.com Daniel Swain

    Things starting to look more interesting, particularly for the storm slated for about a week from now. Stay tuned….

    • sc100

      Yeah, I’m pretty excited for these storms next week as well. It’s looking like at least 7 days of continuous storms without many breaks in between, and things could stay wet after that. A very good, moist flow. Are you going to be putting out a new update for next week?

  • Nicholas

    Even the euro is looking decent in the long range.

  • Dan the Weatherman

    Things are definitely looking more interesting here in Socal regarding next weekend’s storm. Here is an excerpt from this afternoon’s San Diego WFO AFD:

    BY THE END OF THE WEEK…THE HEMISPHERIC PATTERN WILL ALLOW STRONGER JET ENERGY TO SHOOT ACROSS THE PACIFIC AND DIG INTO AN AMPLIFYING TROUGH OVER THE FAR EASTERN PACIFIC. ATLANTIC TELECONNECTIONS AND A STRONG UPPER RIDGE OVER EASTERN N.A. SUPPORT THIS SCENARIO WHICH BRINGS INCREASING CONFIDENCE TO A WET FORECAST CENTERED AROUND NEXT WEEKEND. MODELS DIFFER ON TIMING AND STRENGTH OF THE TROUGH THAT ULTIMATELY DEVELOPS ALONG THE WEST COAST…BUT THE 12Z RUNS ARE ALL ON BOARD WITH A STORMY PATTERN OVER THE WEEKEND. GIVEN THE TRACK RECORD OF THE ECMWF OVER THE PAST FEW MONTHS…IT IS THE MODEL OF CHOICE AND THE MOST AGGRESSIVE WITH THIS SYSTEM. AS ADVERTISED… THERE WOULD BE SEVERAL DAYS OF RAIN AND/OR SHOWERS WITH VERY LOW SNOW LEVELS. EXPECT SIGNIFICANT AMOUNTS OF RAIN AND MOUNTAIN SNOW…VERY CHILLY DAYS…AND A PERIOD OF STRONG WESTERLY WINDS AS THIS SYSTEM MOVES THROUGH.

  • Ken K.

    It is looking more like a period of wet weather for So. Cal. Maybe a weeks worth, I am keeping the faith for this change. Dan you are right, it is unusual it go this long without some type of pattern change. Guess we will know at the end of the week. Redland your grove is most likely ready for some beneficial rain.

  • alan

    Just for fun, the super long range continues the fun here at the end of March
    http://www.woeurope.eu/cgi-bin/expertcharts?LANG=eu&MENU=0000000000&CONT=namk&MODELL=cfs&MODELLTYP=1&BASE=-&VAR=prec&HH=468&ZOOM=0&ARCHIV=0&RES=0&WMO=&PERIOD=

    and into April
    http://www.woeurope.eu/cgi-bin/expertcharts?LANG=eu&MENU=0000000000&CONT=namk&MODELL=cfs&MODELLTYP=1&BASE=-&VAR=prec&HH=612&ZOOM=0&ARCHIV=0&RES=0&WMO=&PERIOD=

    Wow, it just keeps troughing around the west coast with storm after storm from later this week and all the way through April, we’ll see, definitely grabbing on to a longterm pattern change though

  • alan

    LA NWS trying to be conservative:
    ON SATURDAY A FRONT MOVES ACROSS THE AREA. THIS SHOULD BE THE BEST DAY FOR RAIN TO OCCUR. THE EC ACTUALLY BRINGS A DECENT AMOUNT OF RAIN TO THE AREA. THIS WINTER HOWEVER HAS SEEN A NUMBER OF WET LOOKING STORMS THAT TURNED OUT TO BE MIRAGES SO NOT GOING TO HIT ANY PANIC BUTTONS YET.

    SD NWS a bit more optimistic

    THE FAIR AND SEASONALLY MILD WEATHER WILL BE COMING TO AN END THIS WEEKEND AS LOW PRESSURE TO THE NORTH AMPLIFIES SOUTH ACROSS CA. THE 00Z GFS/ECMWF MODELS DO NOT AGREE ON THE TIMING OF THE TROUGH THROUGH THE AREA…BUT BOTH INDICATE IT WILL BE WET OVER THE WEEKEND WITH FRI BEING A TRANSITION DAY AS STRONGER ONSHORE FLOW DEVELOPS…
    AND THE MARINE LAYER DEEPENS. EXPECT WET AND COLD WEATHER FOR SAT INTO SUN…WITH LOCALLY HEAVY PRECIPITATION POSSIBLE AT TIMES…AND LOW SNOW LEVELS.

  • redlands

    Am still not too excited — its still too far out — wont get excited until i see some results in the Redlands, Ca area

  • http://weatherwest.com Daniel Swain

    Well, I’m starting to become convinced that the next 10 days are going to be pretty interesting, especially by this winter’s standards (and especially in the northern 2/3 of the state). Heavy rainfall is looking more likely, but more interesting to me at the moment are the very unstable conditions already being progged for next weekend. Snow levels will be quite low…probably 1500 feet or lower in the north…and the thunderstorm potential is already looking quite high. I’ll try my best to have an update today, definitely by tomorrow night…

    • PacificStorm

      Hodographs even showing some curvature both Saturday and Sunday in most of the Sacramento valley! Pretty fun week on tap!

  • redlands

    I see The San Bernardino Valley/Riverside Valley areas forecast for next Sunday is 43-53 — which I find interesting — although i think its too far out and too late in March to get those types of temps

  • Nicholas

    Sounds like So Cal could get shafted if the GFS is right.

    • alan

      that’s what worries me too, and LA NWS is taking note of it and hesitating on any slam dunks for south of point conception. SD NWS is putting a lot more faith in the ecmwf based on it’s model performance this year, and it is the much wetter and colder solution. SD NWS has already mentioned valley rain totals of 1 to 2 inches over the weekend, 3 to 5 inches in the foothills & a few feet of snow for the mountains… jumping the gun? i don’t know, confidence seems to be pretty high for them…

      ..any thoughts on the possibility of a continuing wet pattern through April? Historically it is not too far fetched to have a dry dec/jan/feb turn to a wet march/april/may, i.e. a “late winter”

  • alan

    GFS is gettin’ more in line with it, and socal storms again the 24th & 28th

  • coldspot

    Well the winds are starting to ramp up here ahead of the “big” storm. NOAA Medford says hurricane force winds along coast possible tonight. Snow around Siskiyou county to be measured in feet in the normally wetter locations. By tomorrow morning snow level to be around 2000′. I-5 will definitely be impacted if not altogether closed during parts of this event. I’ll keep posting updates as time permits.

  • PacificStorm
  • sc100

    Wow, what an interesting week ahead for Norcal. An interesting, and not too common, pattern is setting up for tomorrow where the front will stall over most of Norcal for at least 24 hours, potentially bringing some very significant rainfall to some areas. This is something that always bears watching. Then there’s a small break before the next system comes and brings a good amount of rain for Thursday and Friday. Some areas in the foothills and mountains probably won’t get any break at all in between systems. Then plunging snow levels and thunderstorms for Saturday and Sunday.

    NWS SF this morning also talked about the possibility of an atmospheric river event developing next week when the MJO moves into the Western Pacific.