Powerful El Nino likely to bring heavy precipitation—and possible flooding—to California over the next several months

Filed in Uncategorized by on November 19, 2015 5,462 Comments

Summary of recent conditions

anomimage (26)There continues to be much conversation surrounding the relative lack of major storms in California so far this autumn. Precipitation so far this season has been somewhat below average across the more populated coastal parts of the state, although very early Sierra Nevada snowpack numbers are actually looking pretty good at the moment. Temperatures have (finally!) cooled from their record-shattering October values, and have been fairly close to average over the past couple of weeks.

Recent modest rains and cooler temperatures, though, have so far done little to mitigate California’s worst drought on record. Iconic drought-related milestones are still being reached, from Folsom Lake’s all-time record low level to the recent discovery that as many as 20% of California’s trees could eventually die as a result of the drought and bark beetle stresses already experienced.

 

Interactions between El Niño and the jet stream’s seasonal cycle

Should we be worried that California has yet to experience an epic deluge so far this fall? What happened to the ostensible “parade of storms” that is so often talked about in the context of major El Niño events? I would argue that the most appropriate answers to these questions are “no” and “it’s coming,” respectively.

 

The effect of even very strong El Niños upon the Pacific jet stream is much more pronounced during December-March than during September-November. (NCEP via ESRL)

 

After four consecutive years characterized by a remarkable lack of storms in California at any time of year, it’s easy to forget that the autumn can be an extremely variable period from a meteorological perspective. Transitions seasons (autumn and spring) in tend to be highly volatile throughout the Earth’s middle latitudes as cold, dry polar and warm, moist tropical airmasses interact with high frequency. But California is a bit unique in the sense that it lies near the southern margin of the Pacific jet stream, and is therefore quite susceptible to relatively subtle shifts in the storm track. This is especially true during the September to November period, as during these months the Pacific jet stream is often quite strong but tends to be focused well to the north of the state, up in Washington and the Pacific Northwest. California does sometimes experience major storminess this time of year due to transient, temporary shifts in the jet, but in general sustained wet periods are the exception rather than the norm.

Schematic by Emily Underwood showing why the Pacific jet stream does not respond strongly to El Niño during autumn.

Schematic by Emily Underwood showing why the Pacific jet stream does not respond strongly to El Niño during autumn.

Since the west-to-east flowing jet stream is fundamentally driven by the large temperature differences that exist between the warm equatorial region and cold polar region, its location, strength, and trajectory depends strongly on the orientation and magnitude of temperature variations across the Earth’s surface.  With the approach of winter, temperatures in Northern Hemisphere begin to cool more rapidly—and the region of maximum north-south temperature differential over the Pacific Ocean starts to shift southward. The net result: the jet stream’s typical latitude from December through March is much reliably further south—and closer to California—than during the autumn.

Why is this seasonal cycle critically important during an El Niño year? Well, the primary means by which El Niño affects California precipitation is by enhancing the low-latitude (subtropical) branch of the jet stream. The subtropical jet stream is not always a totally distinct feature in the weather charts—it tends to be weaker and more discontinuous than its more robust northern cousin (the subpolar jet). Sometimes, the subtropical jet is not discernable at all in a particular region, and at other times it effectively merges with the northern stream. But during major El Niño years, the subtropical jet over the northern Pacific Ocean tends to be stronger, better defined, and further to the south.

This strengthening and southward shift of the subtropical jet during El Niño occurs primarily because strong warming of an already warm region (the eastern tropical Pacific) tends to enhance the north-south temperature differential across the Pacific basin. Heat from anomalously warm ocean temperatures is transported vertically and eventually northward by unusually active tropical convection (thunderstorms), warming the upper atmosphere in the lower latitudes. (Climatological sidebar: this effectively leads to a regionally-enhanced Hadley Cell circulation).  Anomalous El Niño-induced upper-atmospheric warming occurs only so far north, and during the autumn months the jet stream tends to be too far north to “take advantage” of this strong lower-latitude temperature gradient. As the jet shifts southward during winter, however, the subtropical branch of the jet is in a favorable position for intensification. It is this effect that can bring California its infamous “parade” of winter storms—and, in some years, excessive precipitation and eventually flooding and mudslides.

One sentence summary: A strengthened subtropical jet stream—which is the primary means by which El Niño brings increased precipitation to California—is unlikely to occur prior to winter due to the intrinsic seasonal cycle of temperature variations across the Pacific Basin.

 

Tropical Pacific warming during El Niño increases the north-south temperature differential, strengthening/shifting the jet stream southward and bringing increased California winter precipitation. Illustration by Emily Underwood.

Tropical Pacific warming during El Niño increases the north-south temperature differential, strengthening/shifting the jet stream southward and bringing increased California winter precipitation. Illustration by Emily Underwood.

 

El Niño now appears to be strongest in modern observational record

Over the past 8 or 9 months, there has been a lot of animated discussion over whether the tropical Pacific could possibly warm as much as was being indicated by the dynamical models. A more than +3C anomaly—which was foreseen by most of the flagship international seasonal forecast models (like the American CFS and the European ECMWF), seemed, to many atmospheric scientists, to be an implausibly high outcome. Even in recent weeks, there were concerns that the critically important Niño 3.4 region may have “leveled off,” or perhaps had already peaked.

Those concerns ultimately turned out to be unfounded, as earlier this week ocean surface temperatures in the canonical Niño 3.4 region reached 3C above average for the first time in recorded history, validating dynamical model forecasts made many months earlier. This weekly value exceeds the maximum weekly value recorded even during the so-called “super El Niño” events of 1982-1983 and 1997-1998. While El Niño impacts do not correlate directly with the magnitude of SST anomalies in any particular section of ocean (and we’re still some way off from an all-time record 3-monthly peak), this is still a major geophysical milestone—and one that has significant implications for the coming winter in California.

 

 

Outlook for California Winter 2015-2016

Top-tier El Niño conditions are now an observational reality, not a prediction. As discussed above, we are now approaching the time of year when El Niño’s influence upon the Pacific storm track tends to be more pronounced. So, with that in mind, how does the upcoming winter look?

The newly-released November international model (which includes ECMWF) ensemble depicts very wet conditions over California during January-March. (CPC)

The newly-released November international model ensemble (which includes ECMWF) depicts very wet conditions over California during January-March. (CPC)

In a word: wet. In fact, it’s hard to envision a set of mid-November observations and model output that would lead to higher confidence in a wetter-than-average California winter than the ones currently in place. The latest dynamical model forecasts are calling for well above average precipitation throughout California during the January-March period, and the recent forecasts from the CFS model have shifted towards a wet December as well. These same models are suggesting a large-scale atmospheric pressure pattern that is strikingly similar to that which occurred during California’s wettest historical winters (including the 1982-1983 and 1997-1998 El Niño events).

Seasonal forecast models are predicting a large-scale atmospheric pattern during January-March much like that during California's wettest years. (CPC)

Seasonal forecast models are predicting a large-scale atmospheric pattern during January-March much like that during California’s wettest years. (CPC)

Ultimately, it is this latter point that matters more for the conditions that might evolve later this winter. While the models used for seasonal forecasting incorporate the same basic physics as those used to predict day-to-day weather, for reasons of computational efficiency they do not have anywhere near the same spatial resolution as weather models. This means that seasonal forecast models can’t resolve California’s complex topography (in fact, in most of these, the Coast Ranges don’t even exist, and the Central Valley is part of a gradual upward slope toward the Sierra Nevada). Ultimately, this makes it impossible for seasonal forecast models to accurate simulate the dramatic orographic enhancement that occurs in California’s mountainous terrain during major storm events. Seasonally simulated precipitation anomalies, therefore, are very likely lower bounds on what might actually fall during the coming winter if the simulated atmospheric setup actually occurs.

It’s not possible, at this point, to be more specific about how much rain might accumulate in California this winter. But previous top-tier El Niño events have brought annual totals on the order of ~175-200% of average in many spots—and this number is consistent with recent forecasts made by the CFS.

 

Animation of seasonal precipitation forecast by CFS. All of California is very wet during December-March. (NCEP via tropicaltidbits.com)

Animation of seasonal precipitation forecast by CFS. All of California is likely to be very wet during December-March. (NCEP via tropicaltidbits.com)

 

Heavy seasonal precipitation totals don’t always lead to major flooding if there are substantial breaks between incoming storms. In fact, some of California’s most widespread and most damaging individual flood events did not occur during El Niño years. But in general, high seasonal totals mean that heavy storms are more likely to coincide with wet/saturated antecedent soil conditions, and El Niño-induced increases in storm frequency make it more likely for several intense events to occur in rapid succession. Thus, flood (and mudslide) risk will likely be greatly elevated this winter, and certainly will be higher than it has been in the past five years. This risk may also be enhanced by the legacy of California’s ongoing, record drought. Chief concerns include increased flash flood/debris flow risk near high-intensity wildfire burn scars and increased risk of levee failures and river flooding due to dramatic land surface subsidence in the Central Valley.

 

Very strong El Niño + record warm Pacific = wild California winter

The eastern tropical part of the Pacific basin is extremely warm due to El Niño, but oceanic warmth further to the north has been even more anomalous in recent months. Virtually every ocean temperature record in existence for the northeastern Pacific has been shattered over the past six months or so. As I’ve discussed previously, some of this incredible warmth has to do with the present El Niño event, as well as dissipated energy from the “El Niño that wasn’t” in 2014. But it’s also broadly believed in the scientific community that at least some of this phenomenal Pacific Ocean warmth is due to Earth’s long-term warming trend.

The super-warm North Pacific has the potential to add extra moisture to the atmosphere this winter. While this more generalized warming is unlikely to affect the frequency of storms, it may well act to add “extra juice” to incoming systems this winter. When we consider this effect in combination with the likely increase in storm frequency due to El Niño, it’s clear the potential exists for a very active winter overall.

There are currently some early signs of the long-awaited shift towards a more southerly and zonally (west-to-east) oriented jet stream over the next few weeks as we head into December. Various model forecasts are suggesting an imminent transition from the present “wavy jet” configuration to a more consolidated one reminiscent of the classic El Niño pattern. In the lead-up to this pattern shift, Californians should probably expect highly variable conditions (and rather unreliable weather forecasts in the short term), as these kinds of transitions are notoriously hard to capture. But there is now pretty high confidence that a fairly dramatic change in the weather is on the horizon—most likely days or weeks, rather than months, in the future.

The GFS ensemble outlook as of mid-November shows a strengthening zonal jet over the Pacific, characteristic of a strong El Niño. (NCEP via tropicalditbits.com)

The GFS ensemble outlook as of mid-November shows a strengthening zonal jet over the Pacific, characteristic of a strong El Niño. (NCEP via tropicalditbits.com)

Finally, it’s important to point out that the planet has experienced nearly 20 years’ worth of global warming since the last big El Niño event in 1997-1998, and nearly 35 years’ worth of warming since the 1982-1983 event before it. In general, this means that there’s more moisture over the world’s major ocean basins than there used to be—which can increase the potential intensity of precipitation when it does occur. But other more complex changes have occurred in the coupled ocean-ice-atmosphere system over the past four decades that are harder to quantify, and may have less obvious (and less predictable) impacts upon overall Pacific climate. These influences could hypothetically add to (or subtract from) the overall impact of El Niño in California in the future.

Despite these added uncertainties, however, it appears quite likely that the present El Niño will exert a powerful (and likely dominant) influence upon California weather this coming winter. There has never been a year in California’s history with this much advance warning regarding the potential for very heavy precipitation, and there is still time for individuals and government agencies to take steps to mitigate the related hazards likely to emerge in the coming weeks and months (fortunately, all evidence suggests that the relevant authorities are taking this El Niño seriously). And—as California’s state government and water agencies have gone to great lengths to emphasize—even a very wet winter in California is unlikely to erase the profound effects of California’s multi-year drought. In many ways, the present situation resembles a conundrum that the Golden State is likely to face more often in the future: how to manage a greatly increased risk of extreme precipitation and flooding despite the presence of long-term water deficits.

One sentence summary: One of the strongest El Niño events on record will very likely bring a wetter than usual winter to California, and there will be a substantially increased risk of heavy precipitation events and associated flooding.

Pictured: one heckuva El Niño event. (NOAA Coral Reef Watch)

Pictured: one heckuva lot of warm water. (NOAA Coral Reef Watch)

 

Special thanks are due to artist and naturalist Emily Underwood, who distilled several complex geophysical concepts into two beautiful scientific illustrations produced specifically for this post.

© 2015 WEATHER WEST

 

 

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  • Gandalf the White

    I feel bad for the semen in the Pacific Northwest dealing with the very high surf.

    • Chatman

      ??? You do mean seaman, right?

      • Gandalf the White

        Yes a typo.

        • Weatherwatcher

          “Typo”

  • craig matthews

    WOW!!

    • Wow it’s not a 384hr forecast for Dec 80th #Bandini

    • Ian

      A bit breezy eh.

    • Brian

      WOW!!!This is right over Ca and this is also not in fantasyland either.

    • Slow
      Deep
      Penetration

      • DelMarSD

        Lol

      • Bob G

        Would that be a lot of rain, or just jet stream winds?

        • DelMarSD

          Mostly winds, I think. But rain as well.

    • Robert T.

      Craig 63 degrees at 16 miles east of Santa Maria. Wind at Branch Mtn 16 with gusts to 21 and it is way more on the 166 corridor. In the past you said you were familiar with this area. 51rh here while Figueroa is at is at 15rh with much less wind. Don’t want to pull out the belt weather kit but, on kestrel 35+. Been out here since 2008 and do not remember this type of weather in December. I would expect ridge top winds to be this way at this time of year(in addition to what should be coming in the forecast). (Winds)Hear them in the trees not feel them on your face. Can’t wait to see if this precip. comes to pass. Any input would be greatly appreciated.

    • jstrahl

      Isn’t if possible, though, that this just means a lot of wind? I’ve seen more than a few big storms turn into big wind makers with little rain.

      • alanstorm

        “Moisture of this intensity impacts our coast once every 5 years, thus areal flooding will be a concern” NWS Eureka

      • Darin

        This is the 200mb chart. It’s got pretty blues though I’m under the impression that this is wind not moisture. Put another way… is there a strong correlation between the 200mb winds and moisture? (weather rookie here)

  • John Curtis

    Great to see Oxnard nws once again backing off the storms for thursday and Sunday

    I attribute it to what I call the pc fizzle. These storms hit point conception and just fizzle out.

    By the way, that is my phrase.

    • yenlard

      Things eventually have to change for us down here in So Cal. It’s frustrating to see all these storms fizzle out. Hopefully in the next two weeks we get some good precipitation.

      • DelMarSD

        The 18z GFS brings lots of rain to So Cal in a couple of weeks. I’d be surprised if we didn’t get a few goods storms in toward the end of the month. Have faith. So Cal will soon have way more water than it can handle…

        • Dan the Weatherman

          We’ll see. I’ll believe it when I see it. It almost seems hard to believe that the ultra-calm conditions as of late can suddenly transition into a very active pattern, but I know a pattern change can do that in a hurry. This current pattern reminds me more of a La Nina setup rather than an El Nino one due to all the heavy rain in the Pacific NW, even though I know that the Pacific NW usually gets a lot of rain in the fall before the pattern shifts south.

      • Dan the Weatherman

        It has been WAY too calm here in Socal for early December. No cold strong Santa Ana winds or rain of any type. One or the other often occurs during this time of year.

    • #1215

      Umm… sorry

  • Tyler Price

    It’s so fun to watch on the 18z GFS how all the ridges just get pushed around and shoved around all over by the pacific by the Lows.. The lows begin progressively getting more aggressive and really just blowing right thru any of the ridges and carving their own paths… Right, for California. Nothing like the previous years when the Ridges dominated all the weather and seemed nearly invincible.. Well this year the RRR has met its match as he hides somewhere in a dark hole in pure fear of the almighty El Niño! cowardly sending his minions to try and do his dirty work (Humphrey, Hubert, and Howard) El Niño then executes his last premeditated attack sending a very strong Jet stream flowing directly across the pacific unimpeded straight into California for months.. becoming their savior as the Californians had been suffering a terrible drought. now he (RRR) trembles in the wake of his fallen and flattened ridges, finally learning his lesson once and for all, leaving the pacific Ocean off to bring famine to another part of the world..
    Lol sorry this wasn’t suppose to be a poem or something I was just gonna type something short and got caught up in some kind of story telling

    • Awesome example of getting inspired and just going with it. “Fallen and flattened ridges” was my favorite part. Nice job.

    • #1215

      We just need that army of storms, led by great general El Nino, to lauch a final and decisive assault into all of California, destroying what’s left of that menacing ridge completely.

      • Upslope

        No. Not “especially SoCal”. I live in LA and while I am as eager to see rain and help the local flora/fauna as the next guy, the rain is MUCH more desperately needed in Central and Northern CA where all of our water storage, agriculture and most diverse ecosystems are located. SoCal can subsist just fine on water from the Sierras and the Colorado R basin if this El Nino pans out. Not saying that’s ideal or sustainable long-term, but we’ll be fine. Things start going horribly, irreversibly wrong if the rains don’t arrive as expected further north.

        • #1215

          NorCal is already getting decent storms. What I mean is that SoCal will finally see some action.

        • hermit crab

          I’m not sure we get that water here. Our reservoir is Lake Cachuma, not doing so well.

          State water here is complicated and confusing. I want to find out more.

  • Chowpow

    My stoke-o-meter is maxed out this evening, I can’t even imagine how stoked the redwoods are.
    It’s also looking like snow levels should drop fast enough on Wednesday night to lay down 12-18″ on the Western Klamaths before the weekend which i’ll have to check out 🙂

    • Dan weather maniac

      Hooray for nature in this pattern! The silent unspoken beautiful natural alive world. That exists in its spectacular uniqueness in this part of the world due to a range of factors including the weather.

      This upcoming wet pattern…yes let our sacred redwoods enjoy it and thrive! They don’t know or care about the daily models like us yet are more wise and ancient than any of us! They will celebrate this upcoming Pattern for sure!

      • Jaymur

        Lovely thought

  • Cheeeeeeeeello

    Dead of Winter: The Donner Party on the Weather Channel on now
    Our own Mark McLaughlin, The Storm King, offers commentary.
    Check it out or DVR it

    • Aloha12

      Thanks! Watching now.

    • Tyler Price

      Thank you so much for saying something!! I’ve been watching this show for about 39 minutes now!! I never knew the history of the Donor party until now, this story is very instense and they were remarkably strong and resilient people.

    • Dogwood

      I was watching last week, but the snow drought during filming was so obvious it took away from the historical gravity of the situation. Trapped in 8 inches of snow was ironic.
      But yeah, quite a story.

  • Bandini

    The downgrade doldrums, will take my totals with reduction sauce.

    • Are you hearing of more downgrades or just lamenting about the earlier complaints. This pre-storm dip seems to be a trend, one I can get behind.

  • yenlard

    I’m hoping the 0z is just a bad run.

    • Unbiased Observer

      There’s bound to be bad runs….they can’t all be good. That’s what I keep telling myself anyways.

      • Unbiased Observer

        The reality is beyond 168 hours the runs are never alike.

        • SoCalWXwatcher

          Yep, as Daniel pointed out yesterday the Ensembles are a somewhat better tool when trying to look that far ahead. It looks to me like they contine to point to West Coast toughing being the dominant feature through the period.

          • Crouching Dallas

            Even more so now, as a result of the GEFS upgrade, right?

          • SoCalWXwatcher

            I guess we are going to see just how much (or little) that upgrade helped with model skill. They look encouraging at the moment though.

    • DelMarSD

      Hopefully. I think the next run will be better. The overall tend is still encouraging, though.

    • jstrahl

      Didn’t we just go through that yesterday?

      • The Thank You Carp

        And again tomorrow 😉

  • Weatherwatcher

    FInally a chance of rain for socal this week!

    • Dan the Weatherman

      It’s about time!

  • Josh

    Just read that the tropical pacific is not as wet as it was in 1998 . Could this pattern just be the new normal. It’s true that California recives most of its moisture from Northern California but SoCal still needs the rain. It doesn’t have to be mutually excusive SoCal and NorCal can share.

  • Bandini

    Not much talk about it but Mt. Shasta is slowly accumulating heaps of snow:

    http://forecast.weather.gov/MapClick.php?lat=41.4093&lon=-122.195#.Vme7rLgrKM8

    • DelMarSD

      Yeah, they could get more than 5 feet by Friday, and more after that!

    • thebigweasel

      High of -2F on Friday eh? Think I’ll stay down at 3,300 feet. Left the sub-zero highs back in Canada. Don’t miss ’em.
      Unfortunately, though, the present rain is warmer than expected. Most of our snow is gone, and the ski park, which had 14″ at the base, is down to 8″ of what will likely be Sierra cement by Friday.
      With any luck at all the storm coming at the week end should dump a couple of feet at the park.

      • Bandini

        What’s the elevation of the park? I’m thinking it’s 5-6K? The mountian from 7-8K up should be stacking up the snow the past week or two and on.

        • thebigweasel

          Base is about 4,200, and the top of Coyote run is 6,900. It really needed to be a thousand feet higher.

          • Lazengaim

            Mr. Weasel: I used to ski the Shasta ski bowl, and for some reason I thought the base was quite a bit higher than Snowman’s Hill, which is 4400ft elev.

          • thebigweasel

            You’re right, and I don’t know what I was thinking when I wrote that. The base is actually about 5,700.

  • alanstorm

    5″ forecasted for Mendo County in the 6 day??Things are really looking really good at home from Bangkok, Thailand, megacity of 10 million. (Of course all hell breaks loose as soon as I go on vacation) Thank God for hotel WiFi cause I got SCREWED in Hong Kong trying to read this blog at the tune of $80. Verizon lied to me…again.

    • Crouching Dallas

      This has to set a record for long range WW commenting! I heard that they seed the clouds with MSG in Thailand – can you verify?

      And as for the money, I think we should start a fund for anyone who needs to read this blog at any time in any part of the world. There are Paraguaian villages that need to know our thoughts!

      • alanstorm

        Thailand is suffering the worst drought in decades. I wonder if there’s any connection with our FORMER dipole, flaccid jet scenario.
        Yes, I could use a blog-friendly data fund, as a snoty Nick the Computer guy from Verizon Intl over the phone informed me. Apparently I’m a Luddite of Leviathan proportions.

  • Quagmire Cliffington
    • Crouching Dallas

      Encouraging! Should we tell Bandini and AlTahoe, or have they rollercoasted enough with this one?

      • Quagmire Cliffington

        Yes. The only waffling I like are the Belgian type.

  • weathergeek100

    SoCal, I wouldn’t get your hopes too high to see much rain in the near future. According to Howard at mammothweather.com:

    “The GFSX has a series of storms following the Thursday/Friday system fairly close to the coast. The main cold pools move inland between Mammoth and the Northern Sierra. This is a track that is not favorable for major precipitation for Southern California. The Dweebs will update later this week…..”

    • BRP

      I read Howard also, he’s a great rain ally for us southers. For a bro that lives and makes a living in Mammoth, its cool to see him post great info for us too. As a realtor I guess he trys to keep all parties happy!

      • weathergeek100

        He’s awesome and seems to really know his stuff. Combines historical data with science quite well. He’s really optimistic yet realistic. I first learned about the MJO and WWBs from him.

    • SoCalWXwatcher

      True, although he was referring to the storms for next week based on the 12z model runs he was looking at when he posted that this morning. It looks like those storms Friday and Monday will produce .25″ or less down here, although SD County will probably do better.

      • weathergeek100

        Even if you guys get .05 or .10 I’ll be happy because it’s SOMETHING. LA has gotten 0.01 of precip since the tropical systems of early October. It’s so depressing to watch the storms fall apart when they hit Pt Conception. I know because I grew up in San Diego observing the weather. I hated it when Norcal got all the goodies and we had to wait and wait and wait. Or, a front looks like it could really maintain strength as it goes down the coast and you think “how could this storm possibly fail? Then it’s a bust and completely falls apart around Santa Barbara. Even though we’re going to get hit pretty hard on Thursday here in the Bay area, I’m still not super content when a system does not traverse the entire state.

  • lightning10

    I will say one thing. I wouldn’t be shocked if my area gets trace amounts with all these colder inside storms. The reason is Whittier will get blocked like always with this flow pattern. Its the worst flow for the area unless thunderstorms fire up and move down from the san gabriel mountains

    • Dan the Weatherman

      NW flow is the worst flow for the Orange area as well.

    • Quagmire Cliffington

      That’s shocking coming from you

  • Nick W.

    This drought is so depressing that Jason “I always say no great chances” Stiff himself isn’t anticipating a lot of rain in the 7-day forecast (Showers Thursday and late Sunday here in SMV). I just hope this storm exceeds his or anyone’s expectations. I’m tired of being Miss Downer all the time.

    • Well the NWS Oxnard is saying 1/4 to 3/4″ possible in Northern SB county, and I think we are about as northern as we can get and not be in SLO county. 🙂

      • Wayne Kerr (Suisun City)

        Yeah, wherever you are…

        • Ian

          Where you at?

          • Wayne Kerr (Suisun City)

            38.235068, -122.033689
            Just curious where in SB county y’re

  • redlands

    87 in Redlands, Ca today 12/9/2015 —- too warm for December Will have to check — but I think the 87 is a record for the day and 2nd warmest overall temp for December — with 88 being the hottest temp ive recorded for december

  • Lycanthus

    There is now a draft agreement from the Paris Climate Summit.

    “In order to strengthen the global response to the threat of
    climate change, Parties agree to take urgent action and enhance cooperation and support so as: To hold the increase in the global average temperature [below 1.5 °C] [or] [well below 2 °C] above preindustrial levels by ensuring deep reductions in global greenhouse gas [net] emissions;”

    1.5C is the new 2C. Considering how many new high temperature records were set in California the past two years with the current ~0.74ºC warming, 2C seems like it would be really, really hot.

    http://unfccc.int/resource/docs/2015/adp2/eng/l06r01.pdf

    • jstrahl
      • Lycanthus

        You are correct, it is still just a draft. Sorry if that was unclear.

        More relevant to this blog in particular, is there seems to be a scientific consensus building that 2C was too high, and 1.5C should be the new limit. Given how hot and miserable the past two summers in CA have been, and we’re at just ~0.74C of the 1.5C, I can see how that might be the case. A 2C summer would be just insane!

    • click

      I was watching the house committee hearing yesterday, called by Ted Cruz to “discuss” global warming/climate change. In his opening comments, he made it clear he was merely seeking confirmation from his stacked panel that AGW is a hoax. Only ONE panelist present was not a denier, and the other seat that could have presented science was empty, reserved as a “courtesy” for someone who did not receive a formal invite as required by committee rules. Setting up the panel with disinformers and a novelist who’s only credential is rhetoric (building strawmen, logical fallacies, etc) without having any knowledge of the science behind climate, and made it sound like the empty seat was there because the “panelist” wasn’t brave or knowledgeable enough to come and discuss climate change. It was a disgusting display, and Mr Cruz allowed the fake skeptics to keep interjecting their own commentary when not asked a question. I really hope Paris talks are successful in some manner, and that despite the (extremely loud and vocal) minority that we can make progress.

      • jstrahl

        Unfortunately, meaningful success is doubtful. From the NY Times link i posted right below you.

        “In reality, even a goal of 2 degrees won’t be met. If all the countries here were to carry out their emissions pledges, it would result in a long-term increase between 2.7 and 3.5 degrees Celsius. Nonetheless, island states that will face catastrophic consequences even under a 1.5 degree rise have been calling for a stronger target.”

        • click

          I absolutely agree that there is 0 chance that the talks will result in any kind of binding accord to meet the 2C target.
          However, with the path we are currently going down, I would argue that ANY commitments or pledges to reduce emissions are “meaningful”, regardless of the target.

          More will need to be done of course, and it will take more than heads of state meeting in an opulent palace (like Versailles). Each and every one of us are stewards of the earth and regardless of your take on climate change, it’s still possible to be conscious of wastefulness and excess. I’m a believer in the “leave it better than you found it” philosophy. We must demand the same of our constituents in Sacramento and Washington; only then will the coal and oil industries be forced to act. They (big oil et al) will not do so voluntarily, regardless of the science or public outcry. Profits outweigh conscience in the corporate machine, and no one will be held accountable. Business as usual.

          This will probably never be read now that it’s on an old page, and I’m just rambling now, but still worth saying. Rant not directed at you 🙂

          • jstrahl

            I read it, i get email notice.:-) Consider reposting it on the new page. I’m not sure meaningless pledges to do something which is itself inadequate on its face is any better than doing nothing, one can argue it’s worse by creating the deception that something is being done.

          • click

            Thanks for reading lol. I see your point, and agree that especially given the number of people that rely on mainstream sensational media that it creates an illusion. Education is key in defeating that mentality.
            As for posting this on the new page, I’d rather not derail the exciting discussion of weather that’s actually happening now 🙂 maybe I’ll save the talking points for a dry spell that hopefully doesn’t hit us for a while! Also, don’t want to give fodder to the trolls, we just got rid of them haha.

  • Nate Klingenstein

    So. I’m sorry for coming back, but I feel the need after you made fun of my mental disorder and my calls look more credible now that the models support them, so maybe you’ll listen a little more and laugh a little less. I’m all about forgiving and forgetting done right. The 00z GFS has latched on to the re-emergence of a North American dipole that I got laughed off the blog for even suggesting.

    http://ggweather.com/loops/gfs_00z_ten_all.htm

    I’m on the record here predicting the rebounding ridge and dipole before any of the models or any professional(except the ECMWF did tip its hand about the dipole in the last frame of one run, which was all I needed to see). You’ve repeatedly accused me of having no scientific basis for my prognostications, so let me recap my reasoning.

    As chronicled so well on the Arctic Sea Ice Forums, El Nino lost much of its atmospheric support in November, partially due to an unfavorable phase of the MJO and IOD. The downwelling phase of the last EKW was already fading around 150W, and total equatorial oceanic heat content had already long ago peaked. As also noted here, this year’s El Nino isn’t actually nearly as large as everyone says: in terms of temperatures(e.g. ONI, MEI) it is very intense, but the volume of warm water moved as recorded by TAO/TRITON was only half of that moved in 1997. The high ONI and MEI readings could very well just be global warming at work. I think the dipole is created by the slowing downwelling of the AMOC and my hypothesized slowing upwelling in the GoA. El Nino fading around 150W and dipole conditions are key, and they will lead to a seemingly endless influx of subtropical moisture being sucked from the ITCZ – but not via jet streaks for California. It’s going to be via pure vicious vacuum by the entire Eastern U.S.

    See the persistent heat in the Gulf of Alaska, which I believe is an artifact of reduced upwelling in the North Pacific rebuilding(and will continue to call the Blob), and the diminishing El Nino failing to flare out along the coastline of the Americas. Combine that with the slowdown in the AMOC and the slower and poorer ingestion of oceanic data into GCM’s and I felt comfortable making the calls even without model support. Slowing thermohaline circulation is an overwhelming force and a much less fickle beast than ENSO, though still not stable, obviously.

    The human mind is capable of incredible information assimilation, pattern recognition, and selective ignorance(not just bug, but also feature). This can all be judiciously used or not: if you get into a tactical slugfest with a chess program, you’re going to lose, but if you strategically see a general theme or favorable endgame evolving that you can draw the computer into, you may well win(I always lose anyway). This is even more applicable to a vastly more complex system like global circulation as rendered by a GCM.

    I fear that we’re applying the same tactical thinking to climate change modeling and policy as well. Perhaps the impacts on the global climate from e.g. a slowing thermohaline circulation are so overwhelmingly massive that they are more pressing issues than equilibrium climate sensitivity values or ocean acidification’s effects on coccolithophores and we’re sitting around counting beans while ignoring a fascinating array of Earth features around us.

    Last but not least, the re-emergence of this festering pattern dramatically reduces the chance that California will get any meaningful precipitation this year, and I fear that planners and public agencies will have listened to the monotonic chants, and California is going to be in actual, serious water trouble next autumn.

    Thanks to anyone who has taken the time to hear me out even though I’m just an autistic high school dropout from a small mountain town with no formal background in… anything, and please no petty arguments over precise terminology — you are battling a training dummy at best.

    • David Thomas

      YAWN

    • Canyon

      Great analysis.

      • SoCalWXwatcher

        Indeed. Other than the fact that there is no indication whatsoever in any of the models of a return of the North American Dipole that haunted us last year, and the fact that the statements implying a fading El Nino regime are patently false (signs of a new KW are now evident) he’s pretty much spot on.

        • gray whale

          Further, Xero has been subtly pointing out the warm-water volume issue all along (if you can call it that, as there was already a lot of warm water in place from #lolmodoki). except doing so in a humble, helpful way.

        • Utrex

          AND to add on to that, there is a lag of ocean to atmosphere coupling of about a month or two. If our El Niño somehow became a modoki in January, those effects would be felt in March.

      • jstrahl

        Yep, just like your claims starting last Spring that El Nino will fail to even develop, let alone reach a record.

    • alanstorm

      Bla bla bla. Why aren’t u talking about the powerful, wind & moisture-laden storm about to slam into NW CA?

    • Scott Turner

      The problem with suggesting groupthink is that you walked into a blog written by somebody whose analysis, outlook, and research has earned him a tremendous amount of credibility, and who has, for the most part, been correct in his interpretations for a very long time. Implying that we are not capable of thinking for ourselves when we base our information on somebody we trust (not to mention facts and data obtained from a variety of data sources) a great deal comes off, at best, as condescending and ill-informed, and, at worst, trollish.

      Furthermore, you continue to make predictions that directly contradict what WeatherWest has described as the strongest possible indicators that California will have a wet winter using evidence that he has directly contradicted and refuted numerous times. Your arguments might have received more traction if A. they didn’t directly contradict a trusted source and B. doing it in such a way that suggests the same kind of willful ignorance that you’re implying posters on this message board are guilty of. What looks like groupthink to you is more like posters disregarding what you say because of how you present it and because the evidence we have been given by a trusted source directly contradicts you nearly across the board.

      That’s my take as to why the board seems so “resistant” to your ideas.

      As for criticisms directed to you because you have a mental disorder, that is absolutely unacceptable. Nobody should make any assumption that any underlying condition prevents you from deserving the same respect as anybody else.

      • andhravodu

        Just wanted to say this is the exact sentiment of mine, and your sentences are pretty identical to mine. But you know, didn’t want to feed the trollish behavior. Only thing is, the few posts I have seen regarding his mental disorder were more explanatory, or offering a possible justification, but this latest post just comes as pompous. And the disclaimer at the end always cracks me up. No, I don’t know anything, but here me out guys, heh, why don’t u respect me

      • Bob G

        Very well said

      • Darin

        He came with a theory, connecting dots, a link, causal analysis. It may all be wrong. You spent 1561 characters (including spaces) not talking about his theory.

        • Scott Turner

          I did. I said that most of what he has said directly contradicts evidence that has been presented time and time again here and elsewhere.

          • Darin

            Seems that’s all that needs to be said.

    • Crank Tango

      Get over yourself dude.

    • mosedart

      Well spoken. This place gets a bit hive mind and many people are very nervous so they don’t like to hear any analysis that says it’s going to be dry again this year.

      Contrarian analysis gives us the opportunity to discuss the points and debate whether they are correct or misjudged which is a great exercise. I’m certainly not educated enough in climate/meteorology to do so but I hope those around here that are will be more patient and have a rational discussion with you.

      • jstrahl

        People are disposed towards analyses that are science based, Excuse us..

    • The Thank You Carp

      If you are right about the AMOC, we should know by…

      The Day After Tomorrow

    • NA dipole ridge does not migrate north from sub-tropics. You may be seeing something else that I am missing.

      Is you grand conclusion that a reemergence of ridging will lead to less than anticipated precipitation over CA? There is precedent, but it will not be a return of the RRR.

    • jstrahl

      Sorry, still no science from you.

    • Thor

      “reduces the chance that California will get any meaningful precipitation this year”

      California is receiving meaningful precipitation as I write this…indeed as you were writing this last night.

  • David Thomas

    any ways back too the weather this little guy on DEC 18 wish is a friday showa vary nic low snow event it looks like a vary low snow event hard too tell at this point but looks like snow levels 1000 too 2000ft with this event

  • Dan the Weatherman

    The following excerpt is from CPC’s Experimental Week 3-4 Outlook discussion which could explain why it hasn’t felt like an El Nino pattern in portions of CA (lack of rain in Socal for example) over the last month or so:

    “During much of the month of November, subseasonal tropical variability has disrupted the pattern of anomalous tropical convection from more typical El Nino conditions. The variability has been primarily associated with equatorial Rossby wave and Kelvin wave activity as the MJO, in more canonical terms, has been weak or incoherent. The majority of dynamical model forecasts of the MJO continue to indicate weak MJO activity and the MJO is expected to remain a minor player in the tropical atmosphere at the current time. The latest precipitation and wind observations and tropical rainfall forecasts from model guidance indicate that a configuration of anomalous rainfall more consistent with El Nino will return to the Tropics as a whole over the coming weeks.”

    Hopefully now that conditions in the tropics more typical of El Nino are expected to return, that storms can penetrate more into Socal in the coming days and weeks ahead.

    • gray whale

      great post Dan

  • David Thomas

    i had too post this on sac facebook pages

    sunday looks dry and sac has rain from the 06z GFS and the past few runs i noted that the next storm dos not come in tell monday

    rain ch for sunday needs too be lower or re moved from the forecast and rain for sunday night and monday needs to be bumped up right now they have it the other way around

  • Bandini

    Hey Al, looks like snow totals/probability “could” be moving in the right direction. Good morning update from Reno and the Winter Storm Warning also upped them a bit, not the 1-2 feet at Lake Level but a tad higher. If you read the discussion they mention that even though the cold air could be delayed, it could still be an all snow event at 6,500-7K. I’m just hoping for a double snow day. Far fetched perhaps, but a slim possibility.

    * TIMING: SNOW WILL MOVE INTO THE LAKE TAHOE BASIN LATE TONIGHT
    WITH HEAVY SNOWFALL BY THURSDAY MORNING. SNOW WILL DECREASE
    BY THURSDAY EVENING WITH SNOW SHOWERS LINGERING INTO FRIDAY
    MORNING.

    * SNOW ACCUMULATIONS: ABOVE 7000 FEET…1 TO 2 FEET WITH
    LOCALLY UP TO 3 FEET NEAR THE SIERRA CREST. BELOW 7000
    FEET…7 TO 14 INCHES EXCEPT 12 TO 18 INCHES WEST OF HIGHWAY
    89.

    • rob b

      I just read the Reno AFD, definitely more positive overall. Just hope it’s correct. The winds have already started to pick up I noticed.

    • AlTahoe

      Yeah I just read that. I am going to stick with 6″ at my house and maybe I will be surprised with more. Heavenly should do well since most of the good skiing is above 7500′. I would imagine all of the trees will be open up there on Saturday. The Sunday storm sounds like a big winner for all of us.

      • Bandini

        Me too. 8-15″ for my location so I’ll be happy with 8″.

        • maddogokp

          Me too! But get greedy, another 1 – 2 feet Sunday!

          • AlTahoe

            Open snow has lowered the Sunday totals to 4-10″ at lake level.
            Two days ago they had 36″-49″ for lake level through Sunday. Now it looks like I will be lucky to hit 18″ so it goes

          • gray whale

            I think that was an old update? He updated an hour ago with this:
            “We could see 10-18 inches at lake level and 1-3 feet on the mountains by Friday morning.”

          • AlTahoe

            Yeah that is for the Thursday storm and I am still going with 6″ for my house. It has been almost 60 degrees the last 3 days and with no snow on the ground so it will take a while for it stick on wet warm ground. I don’t think he has taken that into consideration. The Sunday storm has been lowered to 4″-10″ now for lake level on the east side. I am in the middle of south Lake Tahoe near the water so we usually get the same totals as the east side in his forecast.

  • Ian

    Another record warm night at 48F ? – hey there’s still a couple hours to drop 20 degrees a little closer to average. LOL!

    Precip chances looking a lot better at lest for the mountains here where we’ve bumped up to 70% Thursday night through Friday night. Maybe good for a few inches once the snow levels drop by Friday morning.

    • Bandini

      Mota is going to need a base to make trackshen with his raindear slay.

      • Ian

        I have a bad feeling in a fit of frustrayshun he left his wife and ninos, Mt. Rainier bound, and took one. last. epic. sley ride….

        ….into a forever blizzard of pure bliss…

        • Aloha12 (San Clemente)

          Ha…if he knows anything he’s headed for Mt. Baker… maybe share his brand of ‘slaying’ to the Canucks at WhistlerBlackcomb.

      • SoCalWXwatcher

        It’s “sley” not “slay”. For goodness sakes, man, spell it correctly. 😉

  • alanstorm

    HOLY MACKEREL!! I ALWAYS MISS ALL THE FUN!!
    NWS Eureka on Tonight’s NW CA potent Storm:
    “Model depicted integrated water vapor transport values return intervals indicates that moisture of this intensity impacts our coast once every 5 years. Thus areal flooding will be a concern.”
    Shouldn’t this be big news for this blog?

    • Bob G

      Could you shift it further south a bit 🙂

    • Ian

      You live in a bubble up there on the lost coast!

      That is awesome to hear, send it south after you’re soaked!

    • weathergeek100

      Well, the majority of the state isn’t getting pounded as hard as you so…..if you live north of the bay area, you don’t belong to this blog! Just kidding just kidding. This is indeed great news.

      • Bob G

        Yea. At least I hope Shasta dam gets a good filling and snow in the Sierras

        • osc3

          Yes, filling Shasta Lake is a very big deal for CA.

      • alanstorm

        Strong, steady & wet ZONAL FLOW IN DECEMBER is great news for any part of our drought ravaged Golden Brown state. Theres even a small stream flood advisory. This one looks pretty powerful on the satalite. (Can’t post the image from this hotel WiFi) When I get back home next week, I fully expect to hear the sound of babbling creeks.
        But if it suddenly stops raining, I’m leaving the country again!

    • thebigweasel

      I’m waiting to see how this compares with last December’s drenching (we got 12″ for the month). If the forecasts hold, we might beat that by about the 15th. With snow, as well.

    • Darin

      Daniel had brought it up in one of his thread comments about the possibility of 20″ over next 16 days in Northern Coast. He says he’s got another post in the pipeline. I’m guessing it’ll touch on this.

  • Bob G
    • tomocean

      Wow. That sure flies in the face of some of the wing nuts here who think the RRR has returned.

      • Canyon

        People who believe daily predictions for 3-4 weeks out also fall into that wingnut category!

        • tomocean

          And people who look at all the data showing an extremely strong El Nino currently in place, which generally leads to very wet winters in California, would hardly be classified as wing nuts. Seems like all of the computer models are supporting that belief.

        • Bob G

          Daniel has discussed these model runs in the past. While individual runs can be misleading trends are not. And the closer we get the more meaningful the trends are.

      • David Thomas

        and wish they stop the RRR has not return that is not the case this winter season

        • tomocean

          I couldn’t agree more David. It is gone! It could be pouring rain on their heads and they’ll still be asking when the RRR is going to go away.

      • Wayne Kerr (Suisun City)

        We’re all wing nuts in some way or another… haRdy haR haR

        Don’t let ’em rain on your parade

        • tomocean

          I won’t deny that. I prefer the happy wing nuts over the dour, gloomy ones though.

      • Wayne Kerr (Suisun City)

        They’re hardly wing nuts.

      • Charlie B

        The TTT is here. (Terribly Tenacious Trough).

        • click

          As long as its not the Typical Transient Trough!

      • jstrahl

        Every ridge they see is now gonna be RRR:-)

    • It’s very consistent. Not at all like last year!

  • davdorr

    I thought El Nino years were typically dry for the Pacific Northwest. Guess this is not your father’s El Nino.

    • Ian

      Wet fall and drier winter is typical strong El Niño in the PNW.

      So far so good eh.

      • UrbanBazaar (Oakland)

        Yep, all that precip will be shifting our way soon!

    • AlTahoe

      Plus a dry northwest still means 50″ of rain instead of 60″ so they still need to get 50″ of rain. It’s not like every storm is going to miss them

    • jstrahl

      Once again, El Nino’s effects haven’t even started. Read the 2000+ word essay above, please.

  • thebigweasel

    We’ve had about 2″ of rain overnight here, and it’s moderate steady rain now. We’ve gone from 50% of normal last week to 125% of normal now–and our forecasts suggests 3″ more rain by Friday night, changing to snow on Friday.
    Right now it’s warm(ish): low of 43. Lit fire, more to accommodate elderly cats rather than any particular need–it was 66 in here when I woke up.

    • cerrito

      Thanks for the update! Where’s here?

      • click

        LOL, if only you knew how often he gets asked that… According to his disqus profile (and numerous responses to such questions), he’s in Siskiyou County, a bit south of Shasta.

    • SBMWill

      Got a little over 1.5″ in the gauge this morning. Moderate rain coming down temp steady at 49. 15m east of Blue Lake Humboldt county. This next one should be fun 6-12 hour AR NOAA is claiming once in 5 year event for this time of year.

      • click

        Long time no see! how’s the new place treating you? far cry from waterman canyon, no? Send some rain back our way, don’t forget about us! feel free to deliver anywhere within a hundred miles of prickled.inventors.panoramic (map.what3words.com)

        • SBMWill

          Hey thanks click for asking. It’s great spent some time in Mendo now I have made it to Humboldt finally with a more permanent setup. Yes far cry but waterman has a special place in my heart lol. Hoping to get a weather station soon and set up a webcam and post same frame each day same old dream. It will probable take a while just so much to do and people on my case but such is life.

      • alanstorm

        Wow! A poster from Humboldt! We need some commentary from your area, I presume somewhere near Lord Ellis summiit? There’s a recording studio down on Redwood Creek I used to drive to a lot, so I’m familiar with that drive. {I was always late) Anyone in the Eureka/Arcata area into snowsports knows it as well. Chains required at Barry Summit!

  • UrbanBazaar (Oakland)

    For folks who only use Disqus to comment on WW, it may be helpful to add location to the end of your username, if you are open to sharing it. Except for Bandini… everyone already knows where he lives.

    • 38.234705, -122.034178

      Just don’t do what I did, unless you want visitors… lol

      • click

        There’s a new site that is attempting to create a more memorable and easy to use addressing system for the world, it breaks down to a 3 word string that covers a 3mx3m (approx 10’x10′ square for the metrically challenged) area. Some funny combinations out there, and it can depend on what part of your house/property you are in haha. At least there would be plenty of unique names on here.

        http://what3words.com/ – click explore map to find your “address”

        • 38.234705, -122.034178

          That’s interesting. Don’t think I’ll be stating my three-letter word here, though… a vacant lot near my house is close enough! I only hope my words are amusing.

          • click

            haha, i wouldn’t suggest using your *actual* string for obvious reasons, but i can tell you i found gold at potentially.unskilled.incessant (claimjumpers beware!)
            Problem is no water to sluice it out; i already told my wife that any day i have off that its raining i will be down there, since there should be enough runoff in the wash to make it worthwhile. Need that SoCal rain!

          • 38.234705, -122.034178

            Upon scrolling across the map to my location, I came across “complicated mule overdrive” and figured I’ll never be able to top that.
            Good luck with that So Cal rain. you need it

    • iLiveinFresno

      good idea

    • Bandini

      I’m also Muzik n Mota, I should probably post less, it’s OCD at it’s worse.

  • Quagmire Cliffington

    Forecast for tomorrow:

  • Anybody still on here the new blog update is up http://weatherwest.com/archives/3677#disqus_thread

  • Someone else

    Public Service Announcement: The Thank You Carp has passed on; he saw the bait, took the hook, and was finally landed. The next incarnation of that soul is now among us.

    • Darin

      Thank You for you service.

  • osc3_el cerrito

    Planes are approaching OAK to the SE, which is a positive sign around here.

  • Michael Robert Caditz

    After years of living in New Mexico and waiting endless days to catch scraps of Pacific storms, it’s amazing to be on Vancouver Island and witness them , day after day, freshly hatched!

    • SBMWill

      That’s your fault for giving into the hype and living in New Mexico what a rat hole. Just kidding it’s ok but no west coast after I got out of west Texas at 17 I knew I would never go east again.

  • Driving by Donner Lake right now Bandini, my car says it’s 13 degrees out! I sprayed my windshield misters and some of the spray that came out froze instantly

    • Bandini

      Dude we just got back from Savemart, my brother is in town, saw two different people sliding around, one guy was coming right at me in the parking lot going sideways. Ey ohhh.

  • Weatherwatcher

    Could be a major weather event for California :p

    • SoCalWXwatcher

      Looks like somebody dumped alphabet soup in the Pacific just Southwest of CA. 😉