raindancewx

CFS has a +10 SOI in December... It was +9.14 in Dec 2018.

CFS is starting to go to my December forecast, with a cold center of the US. Here is the scary thing: it has a big +SOI (La Nina) in December. That happened last year. If it happens again, the South will roast later in the winter. See how the red is by 150W, 15S and the blue is by Australia around 15S? That's where Darwin & Tahiti are. In December 2018, Darwin was 1006.2 MB, and Tahiti was 1011.7 MB for a +9.14 SOI. Map below has ~1006 for Darwin and ~1012 for Tahiti.

So far, the Northwest mountains have been getting screwed on precipitation, while the Southwest has been doing OK to well.

Not looking great for people forecasting a dry winter in the Southwest. If the storm forecast over NM verifies next week, we may have record November precipitation for Albuquerque for the last 100 years. Already at 1.25" (average is 0.46"), and the record is 1.93". Already top five for wetness. Long-term, November precipitation tends to indicate January precipitation here fairly well too. Not to mention the fact that May precipitation here is highly correlated (r-squared near 0.3) to Nov-Jan precipitation totals here. Wet May here favors warm East/tornado patterns fairly often. Here is the composite for what follows after particularly wet Novembers in Albuquerque. It stays wet. Pretty El Nino-y too, which is shocking. It's not really that surprising though, this has been signaled since September - a big -SOI September is strongly correlated to a very wet January in the West, especially Northern California.

We're at 1.25" precipitation in November through 5 pm 11/21 in Albuquerque. The storm that times up with the big SOI drop around 11/18 is still shown for 11/28 or so. The 1.25" is already near record November precipitation, wettest November here since 2004. Since 1931, the record wettest November here is 1991, around 1.9" - we may beat that actually, as it may rain or snow a bit tomorrow before the 11/28 system. In the past 90 years, November is correlated pretty well to January for precipitation - typically the wetter November is, the wetter January is. Last big wet November here was in 2016, and then January 2017 was very wet too.

Gary Lezak winter forecast is supposed to be out next week. It's been pretty cold Oct-Nov in Missouri/Kansas, which is where is I had the cold centered in winter, I imagine he'll have something similar since he looks at Fall patterns for the LRC. Might not be super wet though.

This looks pretty good right now. Denver is warmer than normal through 11/20 after a cold start, and we're getting a big snow storm 11/21 in New Mexico. Albuquerque is probably just above normal now through 11/20, but will fall below again by the end of the month. For December, I had the center of the US pretty cold, including Colorado and New Mexico, with temperatures trending to slightly above average on both coasts. There is a pretty strong tendency in El Ninos for whatever the US pattern in the second half of October is to shift East, and become the December pattern. That matches my analogs. Last year, you had tremendous heat centered in Montana in the second half of October, and that shifted East keeping the North/East warm. The H2 Oct, but East thing has worked for all El Nino Decembers since 2009 - will be curious to see how it does this year. H2 October Shifted East My Raw Analogs, but +2F for a warmer Nino 4, looks damn close to the spatially adjusted Oct 16-31 observations:

One thing that I can't help but notice with last Fall is how well each two week period corresponded to Winter 2018-19. Will be very interesting to see if that happens again with some similar features (AMO, Solar, ENSO, IOD, MJO timing) to last year. H1 October was February - not as extreme, but close (a lot of the blue areas in Feb were 10-25 below average) In December, the placement was somewhat different, but the cold West Texas warm North idea was there - its just the heat moved East. If the heat had been centered a bit East over ND in H2 October, the cold would have shot up into the West. The first half of November looked like a de-amplified January, with warm coasts and a much colder middle of the US. If the timing relationships were to hold, January & February would be the similar months to last year. December would be very different - with the center of the US very cold, warmer on the coasts (that's what my forecast had, by the way). Here is a look at how this has played out in some recent El Ninos for December 2015 (H2 Oct v. Dec) - similar shift East of the heat like in 2018. 2014 (H2 Oct v. Dec) - some shift in the heat again to the East. Again, some shift east in the heat over Montana in 2009. Now, here is 2019 - I think you have to expect the cold center over Kansas to move East given the recent history? So slightly warm coasts, cold middle. That was my forecast too.

These are (tentative) top SOI monthly matches for Sept/Oct/Nov objectively, for the past 90 years or so - Year Sept Oct Nov Distance 2019 -12.7 -5.2 -9.0 0.0 1951 -11.2 -12.3 -8.5 9.1 1987 -10.6 -5.3 -1.5 9.7 1932 -8.3 -4.1 -4.6 9.9 2014 -6.6 -8.2 -8.0 10.1 1957 -9.4 -0.3 -11.0 10.2 1953 -13.0 -0.3 -2.7 11.5 Looks familiar to me...although I didn't forecast this exactly for December. I do expect the composite warmth/cold to be shifted somewhat east. SOI has had some really impressive negative bursts this month: Date Tahiti (hPa) Darwin (hPa) Daily Contribution 30 day Av. SOI 90 day Av. SOI 19 Nov 2019 1008.38 1009.80 -27.36 -8.52 -8.87 18 Nov 2019 1009.78 1011.20 -27.36 -7.24 -8.68 17 Nov 2019 1012.24 1010.80 -9.17 -5.97 -8.53 16 Nov 2019 1013.57 1010.40 1.84 -5.59 -8.31 15 Nov 2019 1012.81 1009.85 0.51 -5.56 -8.25 14 Nov 2019 1012.31 1010.45 -6.49 -5.67 -8.17 13 Nov 2019 1012.54 1011.25 -10.12 -5.90 -8.28 12 Nov 2019 1011.94 1010.50 -9.17 -5.76 -8.39 11 Nov 2019 1011.42 1010.05 -9.61 -5.18 -8.48 10 Nov 2019 1011.08 1010.50 -14.64 -4.71 -8.51 9 Nov 2019 1011.85 1010.70 -11.01 -4.37 -8.38 8 Nov 2019 1013.13 1010.25 -0.00 -4.38 -8.23 7 Nov 2019 1013.77 1008.40 15.84 -4.69 -8.01 6 Nov 2019 1011.56 1009.75 -6.81 -5.28 -7.93 5 Nov 2019 1008.71 1011.25 -34.49 -5.28 -7.64 4 Nov 2019 1008.28 1010.80 -34.36 -4.51 -7.07 3 Nov 2019 1010.91 1009.65 -10.31 -4.05 -6.62 2 Nov 2019 1011.56 1009.15 -2.99 -4.37 -6.53 1 Nov 2019 1011.89 1008.60 2.61 -4.95 -6.63

My analogs had a -NAO in December, but its kind of wasted in the Northeast since the -NAO isn't at its peak power as a cold signal in December, while Nino 4 warmth is at its peak as a warm signal in December - they more or less battled to a draw in the Northeast in 2009 when both were extremely potent at the opposite sign (29.72C in Nino 4 Dec 2009, -1.93 NAO in Dec 2009 - both near records). There really aren't any cold Decembers in the Northeast when Nino 4 is 29.5C or warmer. I don't think we have a -1.9 NAO in December, but we may have a 29.7C Nino 4 - it's been around 29.5C lately. I mentioned in my outlook that with Nino 4 near record warm, my blend likely needed to be upped 2F - so I did 1953 (x2), 1983 (x2), 1992, 1995, 2009 (x3), 2018, and then added 2F. For the NE, the (weak) tendency is that each 0.1C of warming in Nino 4 in Fall (peaking in Dec) is worth about 0.15F hotter highs in December, although the relationship is curved, with the Super La Ninas also warm if Nino 4 gets toward 27.0C. I haven't looked in a little while but I think the coldest Decembers tend to be in the 27.5-28.5C range in Nino 4, and 2010, 2013, 2017 were in all in that zone.

I like 10-30 inches for our mountains by Friday morning, and then maybe a bit more on Friday. Something like 1.00-1.25" at a 22:1 ratio for the highest mountains. Not sure if it will verify, but my gut says there will be some dry bulb magic with this system late, and it might (briefly) snow down to 5,000 to 6,000 feet, with a quick inch even in Albuquerque on Thursday Night or Friday Morning.

Pretty much identical this week to 2018 outside Nino 1.2 The warmth below Nino 3 is surfacing now. Warm pool to the West should thin then re-develop. Nino1+2 Nino3 Nino34 Nino4 Week SST SSTA SST SSTA SST SSTA SST SSTA 25SEP2019 20.0-0.5 24.8-0.1 27.2 0.5 29.7 1.1 02OCT2019 20.0-0.6 25.1 0.3 27.2 0.5 29.7 1.0 09OCT2019 19.7-1.0 24.8-0.1 27.1 0.4 29.5 0.9 16OCT2019 20.6-0.2 25.3 0.4 27.5 0.8 29.7 1.1 23OCT2019 19.7-1.3 25.0 0.1 27.3 0.6 29.7 1.0 30OCT2019 20.8-0.4 25.4 0.5 27.4 0.7 29.6 0.9 06NOV2019 20.7-0.6 25.2 0.3 27.2 0.5 29.3 0.7 13NOV2019 20.9-0.6 25.6 0.6 27.4 0.8 29.6 0.9 26SEP2018 20.2-0.3 25.5 0.6 27.3 0.6 29.3 0.6 03OCT2018 21.3 0.7 25.6 0.7 27.4 0.7 29.5 0.8 10OCT2018 21.1 0.4 25.6 0.7 27.3 0.6 29.5 0.9 17OCT2018 21.1 0.3 25.9 1.0 27.6 0.9 29.6 0.9 24OCT2018 21.3 0.3 25.9 1.0 27.7 1.1 29.8 1.1 31OCT2018 21.4 0.2 25.9 0.9 27.8 1.2 29.8 1.1 07NOV2018 22.1 0.8 25.8 0.9 27.4 0.8 29.5 0.9 14NOV2018 22.2 0.6 25.8 0.8 27.4 0.7 29.5 0.9

200m+ of warm water below the surface basically east of 130W now. Much less warmth from 130W-170W., with actually a lot of cold. There is a push of warm water moving East, but I think you have to assume there will be a fairly rapid transition to, or at least toward an East based El Nino starting in December. The cold water should at least thin the warmth at the surface over time by Nino 4. There is still some cold water at the surface near South America, so the warmth won't win out initially, but it should in the next few weeks. The event could end up basin-wide again, like last year, but I wouldn't be surprised if it ends up East based late in the winter. It seems like it takes about ~one week for every 10m of warm/cold subsurface water to surface. So you'd be looking at an East-based El Nino or even a 2016-17 pattern (warm by Indonesia, warm by Peru, cold Middle) by February. That would be consistent with my analogs which had a big warm up nationally in mid or late winter.

1953, 1983, and 1992 all had a major SW storm around Nov 20 when I did my analogs - I think those might be good precip analogs for Utah, Colorado, New Mexico and Arizona. I don't think they'll work for the Northwest or California as well. A blend of 1953/1992 has been a pretty decent match to precipitation totals and timing in Albuquerque for close to six months now. The idea with 1983 in there is that occasionally some kind of Blue Norther level cold front will run into moisture coming in from the subtropical jet, and someone will get smoked for snow in New Mexico or Colorado or Texas. I had 2009/2018 in there too, and then 1995 because we should have some extended dry/warm periods in the SW too. There was another big SOI crash 11/16-11/17, so have to watch for something around 11/27. The models are already hinting at it actually.

This is what the European had earlier today through Friday at 6 am. It should be a great event for SW Colorado snow. A tropical system in late-October 2018 also came into the SW last year too. In some ways, the pattern nationally seems like last year, but delayed by 25-30 days. We had 1-3" widespread rains and some snow around 10/23 last year.

I post Southwest stuff because your precipitation patterns are correlated to ours in El Ninos, especially for snowfall. Once we hit our averages last February I was pretty much certain you guys wouldn't get to yours. The AMO cooling was actually a reference to the NE anyway - you guys have been pretty dry. Fall doesn't really indicate temperature patterns too well in winter, but it's usually not terrible for precip patterns.

The negative PDO in winter correlates to a warm Southeast and a cold Northwest - with the NAO forcing a more winter styled pattern in October when it was negative, that was exactly what we saw in October with the PDO negative. Saying "the PDO has been positive since 2014" completely misses the point. The trend is down. Look at the transition by Nov-Apr: 2012-13: -0.40 2013-14: +0.38 2014-15: +2.07 2015-16: +1.70 2016-17: +1.07 2017-18: +0.30 2018-19: +0.51 2019-20: Since 1931, there are no Nov-Apr periods above +0.5 after the PDO is 0 to -1 in October. It will probably be right around 0 or somewhat negative. A cold Nino 1.2 in October also strongly favors that the PDO values in Fall will fall from winter/spring. So far, the cold in November is exactly where you'd expect it to be based on a strong negative SOI in September. Look at the green areas on the SOI map and the places in the US that are cold. I'd imagine once all the warm lows and moisture come out from our storms this week in the Southwest, quite a bit of the cold will burn off, but we'll see. I don't think the models have that built in yet. We're still not that different from last year this Fall - the PDO went negative for a brief moment last year too after all, although not to -0.45.

As long as the waters away from the coast are much warmer than next to the coast, it is just a warm version of the negative PDO. It's not like October was that different but it was -0.45 on the JISAO index. I'm not disputing that the waters along the West Canada coast are still somewhat warm, but relatively speaking, they're colder than the waters south of Alaska.

El Nino with a -PDO November. Indian Ocean is kind of nuts compared to last year too. In real +PDO years, you have the warm ring around the cold waters.

There is a tropical storm in the East Pacific moving North ahead of the system, so I think a pretty widespread precip event is likely. My analogs had several years with a big storm around 11/20 in the SW, so that looks right, at least for now. For NM & Southern Colorado it's probably a rain event initially, even 8,000-9,000 feet up initially, but it would go over to snow later, down to pretty low elevations by Friday. My analogs implied around 0.25"-0.50" for NM with the system - wouldn't be shocked if it came in higher given the dying tropical system plus the other sources for moisture.

This is why I went somewhat colder in the East than last year. Although I don't think this extent of the cold is quite right, I think it will be less cold and less warm on each end. All the modeling had the warm core of the El Nino around 120W last year, this year, it's shown around 180W. I think my idea from late Sept/early Oct is still about right in the tropics -

The new Jamstec is similarly cold for the US for winter as in the last run. It has really exaggerated the differences in the SSTs from the West Tropical Pacific and the East Tropical Pacific. I'd call it an El Nino. The West also trended much wetter. The temperature, sst and precip maps look a lot like my forecast now, although I don't expect the cold to penetrate as deep into the Southeast. The warm West/New England look strikes me as about right though.

From what I remember, if Boston had actually gotten 3-6" or whatever it was last November at the official site, instead of nearly nothing, I would have been within 2-4" of what I had forecast for Boston. If you think it's 40" instead of 27", I'm just low instead of high by a few inches last year, so it doesn't really matter to me. Looking at the forecasts of others, I do think it would be prudent to find predictive variables that are objectively known ahead of winter for precip/temps/snow, other than say, ENSO or the PDO or whatever. Something like a precip pattern in Summer. You guys really live or die with the teleconnection indexes - AO, NAO, PNA, EPO - etc. You can probably predict...most of them correctly in any winter, but all is a tall order. My stuff is designed to be something like 1/3 data mining, 1/3 statistics, 1/3 global patterns. I find that there are like a 100 ways to match on any blend of ocean/atmospheric/solar variables, but it's much harder to have those match and get your weather to match day and date for an extended period - so that's what I try to do. Matching the highs/precip patterns for a long-time with the oceans/solar stuff seems to be a way to lock onto the MJO signal for a few months if nothing else.

Right is for a -4 to -12 SOI Sept-Nov with a 0 to -1 Oct PDO. Left is El Nino winter + an Oct PDO of 0 to -1.

PDO in October 2019 went the most negative it has been in six years. https://oceanview.pfeg.noaa.gov/erddap/tabledap/cciea_OC_PDO.htmlTable?time,PDO There are no cases of the PDO topping +0.5 from Nov-Apr after a reading of 0 to -1 in October for the 1931-2018 period. PDO was -0.45 in October 2019. El Nino October PDO Nov-Apr 1951 -0.32 -1.02 1963 -0.52 -0.88 1965 -0.36 -0.44 1968 -0.34 -0.81 1977 -0.61 0.50 2004 -0.11 0.47 2006 -0.05 -0.04 Similar SOI matches (-4 to -12 SOI in Sept-Nov) with a similar October PDO - Year Oct SOI SON 1932 -0.29 -5.7 1944 -0.40 -4.0 1946 -0.36 -9.0 1951 -0.32 -10.7 1963 -0.52 -9.9 1977 -0.61 -12.0 1990 -0.69 -4.5 2004 -0.11 -4.6 2006 -0.05 -7.2