raindancewx

Ocean heat content for 100-180W at the equator came in at -1.04 - a bit lower than I had it. Still like this blend. Year Sept Oct Nov 1999 -1.27 -1.07 -1.48 2000 -0.12 -0.37 -0.67 2007 -1.03 -1.19 -1.19 2007 -1.03 -1.19 -1.19 2011 -1.01 -1.26 -0.92 2011 -1.01 -1.26 -0.92 Blended -0.91 -1.06 -1.06 2020 -0.87 -1.11 -1.04

This is from one of the US seasonal forecasts, but I think it explains it well (AAM). He gives links where you can see plots of how it looks too. Atmospheric Angular Momentum: https://jimsullivanweather.com/2020/11/21/jim-sullivans-2020-21-winter-outlook-write-up/ Atmospheric angular momentum is, extremely basically, how much westerly flow there is across the globe. Typically, El Ninos feature a stronger / extended Pacific jet due to increased forcing over the Pacific, and higher AAM. La Ninas typically feature the opposite. Above is the seasonal correlation to AAM in DJF. The correlation is weak in much of the U.S., but in general higher AAM features a +PNA pattern with higher heights over Canada and lower heights over the southern U.S…basically a typical El Nino pattern. If you inverse the colors (use imagination) and emulate the correlation for a -AAM, it looks much more like a La Nina with higher heights off the West Coast and across the southern U.S. and lower heights over much of Canada. The AAM over the last year or so has been interesting. It was quite low in the fall of 2019, likely due to increased Indian Ocean forcing and limited Pacific forcing, which contributed to a very ridgey pattern in the mid-latitudes (in particular, across the Pacific) and limited disruption to the stratospheric polar vortex, allowing it to get quite strong by early 2020. It rose later in winter, though was distributed poorly and didn’t shake-up the +AO pattern. The AAM fell again over the summer as La Nina developed and strengthened. It has risen this fall and isn’t dropping back off yet. This atypical AAM for a La Ninia may explain why we’ve had cold weather over western North America and warmth nearly everywhere else in November (and quite possibly December, more later), which is not how La Ninas typically play out (usually, La Ninas start colder than they finish in the eastern US). The fact that the AAM is kind of high for a La Nina isn’t necessary bad, but how it’s currently distributed is poor for winter weather fans in the eastern U.S. and Europe to say the least:

Canadian has a similar look to the CFS for December. Huge changes from the prior monthly outlook for December in the circled areas. Winter overall trended warmer, but it did trend colder from the SE to NM and TX.

New Canadian trended La Nina weaker, with colder waters shifting West over time, other than a possible brief reversal east in March.

There is a pretty strong signal right now in Albuquerque precipitation data for a wet January. I call this the "replication" method for analogs. We get so little precipitation here that if you match monthly totals July-December within 0.2 inches of observations, you can predict Jan-Jun totals pretty well. December is obviously not in yet, so the January signal will change if the month is very wet or very dry. Will update if necessary. Blue highlighted data is a wetter than average month. Top ten matches, and a simpler are blend are shown.

The city ended up seeing nothing - not even measurable rain with the advisory storm. Latest models have the mountains getting snow the next few days, but not too much. The Euro has been showing a bigger storm grabbing subtropical moisture starting around 12/5 or 12/6. It's shown for several runs now.

For November, Nino 1.2 is likely about 21.0C on the monthly data well above the reading last month. Nino 3 is probably 23.8C or so. Nino 3.4 should be about 25.4C. Nino 4 I'd go about 27.9C. The monthly data tends to run a bit warm of the four week averages. The ONI value for SON will be around -1.2C using the rolling CPC 30-year average. Against 1951-2010 averages, it's more like -0.95C for SON. Nino1+2 Nino3 Nino34 Nino4 Week SST SSTA SST SSTA SST SSTA SST SSTA 04NOV2020 20.3-1.0 23.6-1.3 25.1-1.5 27.8-0.8 11NOV2020 21.2-0.3 24.1-0.9 25.7-1.0 27.9-0.7 18NOV2020 21.0-0.7 23.6-1.4 25.2-1.5 27.9-0.7 25NOV2020 21.0-1.0 23.7-1.3 25.3-1.3 27.9-0.7 The waters below the Nino zones still appear to be slowly warming. Subsurface value is around -1.1 for November as I mentioned above.

The Euro has now had a several run display of a huge storm coming into New Mexico around 12/5 or 12/6, and then leaving around 12/8. There was a huge storm in that time frame here in December 2007, on 12/10 or so. My guess is that sucker is the one that blew up into the first big snowstorm of December 2007 for Boston. We'll see how it goes, but I feel like I did my homework this year. That's the start of it. This is the peak - now shown three runs in a row.

There it is guys - the big wet storm of 12/10/2007, right on time. It actually starts much earlier than this 174 hours in terms of precipitation. The first moisture would be ~150 hours on the Euro from now. This is the last two runs. Was shown on the prior run too.

Looks like it will get pretty cold in this time frame. Not sure about moisture yet. My wild card is this system may be able to tap some moisture from the Gulf of California even if the subtropical jet isn't there. But the models don't really show it. But usually the storms that are strong that get far enough south can do it. The last system missed Albuquerque, but areas south and west had a pretty decent little snow event, with 0.05-0.20" liquid falling as snow.

I'd go 1960/2011, or 1960/2007/2011 as the blend for December going by recent conditions and what the models show. Should be an interesting month. 1959/1988 have the right feel to me for December, but they don't really look like November. 1960/2011, and 1960/2007/2011 actually match on a lot of things, +NAO November/November look, identical SOI, similar SSTs, the current CFS monthly depiction and so on. I'd warm up either blend outside the NW by 1-2 degrees though.

Top SOI Matches for Sept-Nov: SOI Sept Oct Nov 1947 11.7 -1.6 8.7 1959 0.5 4.7 11.2 1960 7.6 0.3 6.8 2007 2.2 6.1 9.9 2011 11.1 9.7 12.4 2017 6.1 10.6 10.4 Blend 6.5 5.0 9.9 2020 9.9 4.4 9.2 Simple SOI Match: SOI Sept Oct Nov 1960 7.6 0.3 6.8 2011 11.1 9.7 12.4 Blend 9.4 5.0 9.6 2020 9.9 4.4 9.2 November 1947, and November 1959 were extremely cold. Nov 2017 has intense heat too far West, with the east too cold for November. So I like a blend of 1960, 2007, 2011. The 1960 inclusion gets you a "-NAO" December look to offset 2007/2011 a bit. As a blend, it looks dead on to November. I would warm up the 1960/2007/2011 look outside the NW for December since it is centered on 1992 by 1-2 degrees. Also, in recent years when that warm Montana to Florida look appears, the SW is colder - almost always - than what the CFS depicts.

Quick round up of emerging wildcards for the winter. 1) Solar Activity is rapidly increasing. My research is that some monthly precipitation and temperature patterns are far less or far more likely when solar activity sustains above 55 sunspots/month in a July-June year (i.e. the ENSO year). If we were to sustain at over 55 sunspots in 2020-21, I'd be a lot more optimistic about March precipitation/snow in the Southwest, particularly if the La Nina were to rapidly collapse toward an El Nino. 2) Fall doesn't look like any La Nina since 1950. There is no La Nina since 1950 with a cold middle, warm East/warm West look. The closest thing to a La Nina with that look is 1959, a near-La Nina with a warm NE Pacific. Other years with this look include 2018, 2019 with 2003 and 2014 also somewhat close. 3) After researching it, heavy snow is fairly likely to dump again in the Southwest at some point. This may be the part of the pattern when the NE cashes in again, as with October.

I went through all of the La Ninas since 1950 today. None of them have the "look" of Fall 2020: A colder area in the middle third of the US relative to warmer thirds for the East and West. The closest thing to a La Nina that has the 2020 look is 1959, a cold-neutral ENSO with a very warm Northeast Pacific. That year also followed two El Ninos, with 2018-19 like 1957-58 - the stronger El Nino before a weaker event followed. The La Nina Falls since 1950 tend to have the middle third of the US warm, or the West cold. Neither feature is present this Fall overall. In that respect, 2010 (colder West), and 2016 (hotter middle of the US) are much more traditional even with their weird winter features that developed than 2020. The best matches to Fall are 1959, 2003, 2014, 2018, 2019. All of those years have a warm NE Pacific. So something to keep in mind for winter. The blend is pretty warm for December too, and actually pretty close to the CFS.

Albuquerque missed each time, but pretty decent week for snow down here. Picture is Angel Fire Ski Resort. Snow pack at Taos Powderhorn (the mountain for Ski Taos) currently is third highest snowpack since 2010 for the date. Snow pack for New Mexico is not good overall, but should improve more in the next week. Northern areas are closest to normal as expected in my forecast.

The coldest patch of waters below the Nino zones is thinning, surfacing, and moving east since this time last month. I've zeroed out the -0.5 to 0 and 0 to +0.5 waters on both maps for a clearer comparison. Early December in the CPC maps looks broadly like 1959 and 1988 to me. We'll see how that goes. The 11/20-11/26 period of 2007 is also pretty similar looking to how early December is depicted. Cold December La Ninas in the East often feature a very cold Midwest early in the month - but the Midwest is favored warm. Curious to see the weeklies on Monday. Should give a good idea of how cold November is in all the Nino zones. My guess is 25.25C in Nino 3.4 for November, but will revise if the weeklies are a lot colder/warmer on Monday. If you squint a bit, it almost looks like Nino 4 warmed a tiny bit in November too. Nino 1.2 definitely did. Nino 3.4 is probably about the same as in October.

The north Pacific orientation changes with the ENSO/PDO states. Actually think some of the mountains will see decent snows this week given the little impulses depicted to dive down. When I look at 2007-08, the pattern depicted for early December is similar to about 11/20-11/26 in 2007. If we keep running say 10 days behind 2007, then the bigger storms (at least down here) of Dec 2007 would show up late December instead of mid-December.

Not a drop of rain or a flake of snow in town. But it has been snowing in some spots. I can't believe they went with a winter weather advisory in town. I'm not fully convinced we'll get more than T. I've been assuming T-0.10" total, with some of it as snow if it came overnight.

I have my doubts about these totals (I'd have gone T-1"), but we'll see. Storm is behaving a bit differently than anticipated and has a bit more moisture too. URGENT - WINTER WEATHER MESSAGE National Weather Service Albuquerque NM 248 PM MST Fri Nov 27 2020 NMZ218-219-280400- /O.EXB.KABQ.WW.Y.0020.201128T0600Z-201128T1600Z/ Santa Fe Metro Area- Middle Rio Grande Valley/Albuquerque Metro Area- 248 PM MST Fri Nov 27 2020 ...WINTER WEATHER ADVISORY IN EFFECT FROM 11 PM THIS EVENING TO 9 AM MST SATURDAY... * WHAT...Snow expected. Total snow accumulations of up to one to 3 inches. * WHERE...Santa Fe Metro Area and Middle Rio Grande Valley including the Albuquerque Metro Area. * WHEN...From 11 PM this evening to 9 AM MST Saturday. * IMPACTS...Plan on slippery road conditions.

Edit: I screwed this up - left image is last year. I don't pay for Weatherbell, but he went colder for New England (and out here actually), with more warmth in the South. Anyone know if he changed analogs? He had like 1973, 1988, 2010, 2010 as the blend for a while, but like +1 warmer than the raw blend of those years.

Ignore this - image is from last year. I don't pay for Weatherbell. But looks like they changed their winter outlook again. I'm colder in the West, similar in the middle of the US (I think Texas could legitimately be +5 in a lot of spots) and then warmer in the East.

In the November 1950 storm, you had heavy snow on a south wind in Pittsburgh and a heavy rain event in Buffalo on a north wind, you can get all sorts of crazy stuff if you have a strong high and low interacting in unusual ways. This is from the Washington Post on the 1950 storm For instance, in Pittsburgh, heavy snow was falling in 21-degree air … then as winds shifted from northwesterly to southeasterly … the temperature plunged to 9 degrees, with the arrival of the cold front from the southeast! And while Pittsburgh was at 9 degrees (and heavy snow), hundreds of miles to the north, Buffalo was experiencing a balmy 54 degrees, heavy rain and hurricane-force gusts. It’s hard to believe that the District’s temperature was nearly 50 degrees warmer than Atlanta’s!

I think you'll see the magnitude of warmth on the CFS shift a lot cooler in the next few days for December. Spatial arrangement may be about right.

00Z run 11/26 from the GFS has 40 hours of snow for New Mexico starting around six days from now. It's basically dead on to the SOI crash time frame. I'm sure it will change, but the trend is good.

To me La Ninas are Atlantic driven. If we're really moving to the cold AMO, and I still think we are going to see it mid-decade - then we should start to see much better (colder) La Ninas nationally. 1959 if it verifies was about 4-5 years before the flip to the cold AMO, and that's about where we are now, given the flip to warm was 1995. The hurricane seasons from 1954-1964 are kind of similar to now too, with Hazel, Donna, Hilda, etc. 1961 had a huge system hit Central America super late like this year, and has the QBO/ENSO match you'd want if you like analogs off that stuff. I'd imagine you had (cyclical) low sea ice extent in those Falls too, although still more than now.