raindancewx

The SOI was +15.85 for January 2021. That's the fifth highest January reading since 1932, behind 1939, 1962, 1974, 2011. Top SOI matches for Nov-Jan still look like 1938-39, 1950-51, 1961-62, 1998-99, 2007-08. As a blend, you get a cold West February from those years. February 1962 is a pretty extreme pattern if that's the kind of look we get. The new Canadian will be out tomorrow. I'm not sure if it will show the look in that paper for Feb-Apr or not. My expectation is Nino 4 stays cold for a while, while Nino 1.2/3 both see at least a month or two above average. Spring/Summer will be pretty interesting if Nino 4 remains both coldest and the most extreme of the four regions. I'd really like to see that plume of cold water in Nino 4 push into the waters by the "Box C" zone on the Modoki calculation. That area is fairly well correlated to cold in the West and it never seems to get cold. If you look at the coldest Nino 4 January years from 1950-2019, below 27.5C in January, 17/18 warmed from the January reading to the next Dec-Feb. The exception is naturally 1955, which is actually a decent analog to current conditions, but it was 27.4C in January, not 27.0C or so like this January. Nino4 Jan DJF Gain 1974 26.3 27.56 1.26 1976 26.58 28.19 1.61 1989 26.6 28.49 1.89 1999 26.64 26.97 0.33 1971 26.65 27.79 1.14 2008 26.87 27.48 0.61 2011 26.92 27.37 0.45 1950 26.94 27.15 0.21 2000 26.99 27.46 0.47 1956 27.04 27.77 0.73 1951 27.21 28.3 1.09 1965 27.23 28.74 1.51 2012 27.3 28.28 0.98 2009 27.37 29.41 2.04 1955 27.41 27.05 -0.36 2001 27.43 28.68 1.25 1963 27.45 28.33 0.88 1984 27.49 27.59 0.10

My guess for February is the WPO/EPO/NAO are volatile/neutral(ish) overall, but the PNA/AO remain negative. Early February is supposed to see the WPO favoring SW cold and the EPO favoring eastern US cold, so that'll be interesting.

More precipitation for the Southwest today means Arizona will see more more contraction of the dry January. Of the Southwest states, Arizona will end up the least dry in January after today. I'm expecting some decent contraction of the dryness over California when the map updates again tomorrow.

The SOI has crashed hard in recent days. Should be a decent system in the ten-day time frame from the crash, around 2/8. The big system of recent days for California moving east now times up well with the most recent crash. Date Tahiti (hPa) Darwin (hPa) Daily Contribution 30 day Av. SOI 90 day Av. SOI 29 Jan 2021 1011.25 1004.75 8.91 17.02 14.18 28 Jan 2021 1011.84 1002.75 21.11 17.56 14.30 27 Jan 2021 1013.31 1002.25 30.39 17.55 14.07 CPC also has a cold period in the time frame a storm would come through, so maybe some high ratio / low water content snow.

Here are three objective blends for February 2021. Take your pick. Nino 4 around 27.0C in January...AND a -NAO in January composite. By this method I'd probably go in between the two maps. Top SOI Matches for Nov-Jan, using data from 1931-2019.

The CFS is trending February colder at the moment. My view is it is overdoing cold in California because of the snows right now. But it should be cold in the Midwest & interior West. That makes sense to me. Very similar to my analog blend for winter and February 2008. But I'd probably connect the two cold areas via WY/CO. I'd push the warmth centered over Roswell to about Dallas. That would warm up the south and allow the cold to extend into the interior SW. We'll see though. I'll post the final CFS & Canadian outlooks for February in a few days. CFS had a good forecast for January on 12/31.

Nino 1.2/Nino 3 are quite warm.

Levi's site has the La Nina getting it's ass kicked in the eastern zones, while Nino 4 remains very cold. We're not really in a La Nina in Nino 1.2 or Nino 3 anymore if you go by his figures.

Blizzard warnings for California for up to six feet of snow by Friday, and 100 mph winds. Fingers crossed.

I look at Flagstaff as a proxy for Arizona, and they'll switch to positive anomalies for snow for winter to date by the end of January. The Upper Rio Grande basin in Colorado is now above average, and the north-central mountains in NM are nearing average as of data through yesterday. So the snow pack feeding the Rio Grande is actually in decent shape. Even if the Southwest has large areas that finish wet in January in a La Nina, a dry Spring is still favored. But my research suggests a less dry Spring is possible if large areas of the Southwest pull out a wet January in a La Nina. The pattern is dry overall for the New Mexico valleys, but Albuquerque hasn't hit 60 in like eight-weeks, so it's not like any of the snow on the mountains has melted much. https://www.wcc.nrcs.usda.gov/ftpref/data/water/wcs/gis/maps/co_swepctnormal_update.pdf

The airport got about an inch of snow by midnight 1/25, and it was still snowing until about 1 am. Probably just over an inch fell there, with 0.9" reported for 1/25. I noted way back in October that all ten years to see measurable October snow in Albuquerque had snow in five different calendar months. We're at three now: Oct, Dec, Jan. To keep that tendency alive, we need snow in two of the next four: Feb, Mar, Apr, May. Recent Marches have not had snow, and snow in May is very rare. But I lean toward Feb & Mar, since every prior October snow in Albuquerque has been followed by a March snow.

Meanwhile, in the cold, wet Southwest. Whoops dry warm I mean. It's a La Nina after all. Models still show up to 11 inches of liquid equivalent falling as snow in the mountains of California the next six days.

Nino 4 dropped below 27.0C this week. Except for one week in January 2012, this is the first time for that since the 2010-11 event. We'll see if it continues to trend colder. This event is still similar to 2011-12. However, the 26.9C was the coldest reading in Nino 4 of 2011-12. We're still fairly close to 2007-08 in Nino 4, and that event kept Nino 4 dropping erratically into February. If that happens, we'll drift away from 2011-12 as a good match. Nino1+2 Nino3 Nino34 Nino4 Week SST SSTA SST SSTA SST SSTA SST SSTA 16DEC2020 22.0-0.8 24.3-0.8 25.6-0.9 27.8-0.7 23DEC2020 22.1-1.1 24.5-0.7 25.7-0.9 27.6-0.8 30DEC2020 22.2-1.3 24.4-0.9 25.4-1.2 27.3-1.1 06JAN2021 23.1-0.8 24.7-0.8 25.5-1.1 27.1-1.2 13JAN2021 24.0-0.3 24.7-0.9 25.4-1.2 27.0-1.3 20JAN2021 23.9-0.8 25.2-0.6 25.5-1.1 26.9-1.4 14DEC2011 21.5-1.2 24.1-1.0 25.6-1.0 27.4-1.1 21DEC2011 22.1-1.0 24.5-0.7 25.6-1.0 27.2-1.3 28DEC2011 22.6-0.9 24.4-0.9 25.5-1.1 27.1-1.3 04JAN2012 22.7-1.1 24.6-0.8 25.5-1.0 27.2-1.2 11JAN2012 23.7-0.5 24.8-0.7 25.6-1.0 27.1-1.2 18JAN2012 24.0-0.6 24.9-0.8 25.4-1.2 27.1-1.2 25JAN2012 24.6-0.4 25.2-0.7 25.5-1.2 26.9-1.3

One thing I try to match on is MJO timing. So we'll probably be in MJO phase 7 on 2/1. Some cold ENSO years with high-magnitude phase 7 on 2/1 (1/30-2/3 is my threshold for timing): February 2018, 2012, 2006, 1993, 1990, 1989. If you ignore the early February timing requirement 1999, 2001, 2008, 2017 had amplitude phase 7 too. A lot of El Nino years do too. I did some research the other day: If you get a wet January in a La Nina in the Southwest (seems likely now for at least large portions of Western NM, Arizona, and parts of Utah, and Colorado, Nevada, and California), it does seem like the SW Spring dry signal weakens a bit, but remains. My guess is the weak systems we've been getting all winter won't make it through in the Spring, and it will just be a handful of very powerful upper level lows, probably cold cut off lows that occasionally tap Gulf of California moisture, that bring precipitation. That's probably pretty tornadic if the north is cold and the south is warm, with all the dry and wet air mixing, and it does make me think maybe the WPO will hold on a bit longer than forecast. The right images are what I call the "wet Southwest La Nina" January composite. The left images are the "mixed Southwest La Nina" January composite - where some places are wet and others very dry. The right image seems a lot closer if California gets as much rain and snow as they are forecast to by Friday.

Increasingly looks like California's rain/snow deficits are going to be nearly destroyed or destroyed in the coming days with up to 100 inches of snow forecast in the mountains through Friday Night. A lot of Arizona is going to flip to positive precipitation departures for January after today and Monday. New Mexico already had some areas running above average this month, and the above average moisture should expand here as well.

CFS may radically change by the end of the month, but for now it is on board with the February 2011/2012 blend.

The storm I'm watching the closest is actually the 1/30 (ish) system for NM/CO. That's the only one in the train of systems supported by the SOI crash. It's been trending up in strength on each run of the European. Currently looks like a powerful Pacific cold front for Western NM, but I think it may keep trending up. Euro has up to 100 inches of snow for California over the next six days.

It's the GFS. It's also 15 days out. But still....150+ inches of snow for the mountains of California is currently shown. A lot of it is in the next few days too.

We'll see how it goes. When I looked at the years that had a similar setup to what we see now at the surface, the tendency is for Nino 4 to remain cold pretty deep into the year, even as the other zones warm. Nino 4 getting reinforced by cold waters below the surface moving west and toward the surface is supportive of that. The best subsurface matches for Nov-Jan are probably going to be 1995-96, 2007-08, 2011-12 as a blend, barring a huge last second change late January. That's a pretty typical La Nina look nationally for February.

The MJO on the long-range European update yesterday was forecast to stay in phase 7 from now until 2/20 or so The shorter range models have it in phase 7 through at least week one of February. Good for us in the West for snowpack. Pretty decent warm signal for the East too.

Despite the reputation of La Nina, it does seem like West Texas and north Texas often do fairly well for snow early on in La Ninas. There were some pretty impressive snow events in 2017-18, 2008-09, and 2005-06 really far into the South just off the top of my head. I think Houston, Austin, Brownsville, San Antonio and New Orleans have all had snow in recent La Ninas. Not each city in each year, but you get brief windows.

Update -

Today is the 60th day in a row without hitting 60 degrees in Albuquerque. Hasn't actually topped 57 in that time frame either. Places that have hit 60: Boston, New York, Philadelphia, Denver, Billings.

CPC has Texas strongly favored to be warm in the long-range after all the rain and snow forecast for the Southwest. I wasn't expecting the Dakotas to see record warm highs in winter, but I did expect Texas to have warm highs.

I really can't remember the last time I've seen a model forecast this much precipitation for Arizona within ~4 days in real time. Most of this is by day break Tuesday.