raindancewx

I'll link to my outlook here when I am done. I was checking overall snow patterns in the individual years yesterday. Each of the five analogs I am using had fluky deep-South snow events. The real crazy thing is they all are Northwest of the landfalling systems in the Gulf - typically Louisiana and Texas. My best guess is if there is a fluky deep-South snow event, the timing would be early December (12/1-12/10) or late January (1/21-1/31). We'll see. The snow map showing the fluky pattern will be in my outlook.

The obvious read on the cold season is it probably won't be as warm as last year nationally in Nov-Dec, or as cold as February in the Plains. Probably not as warm as March either. I actually still have January pretty warm though. December & March are my guesses for most different year over year from Nov-Mar. I do have February much warmer, but still pretty cold. Checked the other day - there were fluky deep South snow events in each of my analogs. Trying to figure out when the hell that's most likely to happen. My guess is early December or late January, but it's definitely interesting to see it. Can make the case for 1-2 incredible cold waves in winter in an otherwise warm pattern nationally if you look at years with similar Summers-Falls in 15-day increments.

Nino1+2 Nino3 Nino34 Nino4 Week SST SSTA SST SSTA SST SSTA SST SSTA 01SEP2021 20.3-0.2 24.7-0.3 26.5-0.3 28.4-0.3 08SEP2021 20.7 0.2 24.6-0.3 26.4-0.4 28.5-0.3 15SEP2021 20.6 0.2 24.3-0.6 26.3-0.4 28.4-0.4 22SEP2021 20.6 0.2 24.5-0.4 26.4-0.3 28.2-0.5 29SEP2021 20.5-0.0 25.1 0.3 26.8 0.0 28.2-0.6 With Nino 3 warming a lot the past few weeks I would bite on the current week as a Modoki La Nina look. But I also don't think the month will finish anything like this. In any case, still running much warmer than last year. The 40 or so years since 1950 with cooling in Nino 3.4 from September to Dec-Feb average about ~0.35C of cooling, with 80% of the cooling years seeing a 0.05C to 0.65C drop from Sept to DJF. 02SEP2020 18.9-1.7 23.6-1.4 25.8-0.9 28.4-0.4 09SEP2020 19.5-1.0 23.4-1.4 25.7-1.0 28.5-0.3 16SEP2020 20.0-0.4 23.6-1.3 25.9-0.8 28.2-0.5 23SEP2020 19.6-0.8 23.6-1.2 25.7-1.0 28.1-0.6 30SEP2020 20.1-0.4 23.8-1.1 25.6-1.1 27.9-0.8 Year to date for subsurface, 2011 is objectively the best subsurface match - I suspect pre-1979 years match better, but the data doesn't go back that far. You can see in the Ja-Sp (Jan-Sept) column that the total difference between 2011 and 2021 is about ~0.26/month (2.37 divided by 9 months), and it's double that all other years, even 2017 in second place. Year to date at the surface, Nino 3.4 and 4 are still remarkably close each month to a blend of 1967, 2001, 2011. Nino 3 is actually very close overall too, but September was much warmer than that blend.

Nino 3.4 came in at 26.21C. That's +0.32C from last year. Nino 4 is very similar to last year for September. To be honest, Nino 3 is actually the most interesting - the cold water below the surface is there. But at the surface, it is running warmer than years I don't even consider La Ninas winters like 1959, 1961, 1962, 1966, 1967, 1978, 1985, 1996, 2001. Nino 1.2/3 are both over 0.5C warmer than last year in September.

I'm still pretty happy with the blend I have for winter at the moment. You can see in the 5N-5S, 120W-170W area which is Nino 3.4, it's very close. It's a pretty strong match on the La Nina. There are other issues, but the IOD and AMO should move toward that blend of years with time. It's pretty hard to get a good match on the Nino zones at the surface for September. None of the individual years are great matches. 1959, 1985, 2000, 2001 are decent, but they have pretty big issues. Also have a backup blend for high solar activity. But not sure I'll need it yet.

Really not buying this La Nina as a big deal at the surface. It's getting late fast for it to catch up to last year. To be fair, last year was one of the ten coldest events in Oct-Nov before it weakened. But it was a 25.58C La Nina in Dec-Feb. At the end of the day, I consider 25.50-26.00C La Ninas in winter to be weak. 25.0-25.5 is moderate. <25.0 is strong.

For 1950-2020, there is no winter in Nino 3.4 more than 1.0C colder than September. Not one. Fall can be pretty cold in that zone like last year. But Nino 3.4 is going to be warmer at the surface in September than last year when the monthly data is in. It's probably around 26.20-26.40C on the monthly data for September. The amounts are not trivially small or localized warming either at the surface - As far as ACE goes, post Sam, I'm expecting another 20 to 40 more ACE by the end of the season. Sam is going to be the last gunslinger for a little bit. We have maybe 45 days left before the potential in the Atlantic ends. Each day without a storm lowers the ceiling on the season fast. Also, since 1850, ACE has topped 70 like three times in Oct-Nov. So 200 is a real stretch for me. It took a cat 4 and cat 5 in November just to hit 180 last year. In 2017, for comparison, we had 175 ACE in September alone.

1983 is an example of a year that under-performed the subsurface though at the surface. 26.0C in Nino 3.4 in DJF 1983-84. Despite a -2.25 subsurface reading in October. A lot of that is washing away the 1982-83 El Nino heat. But you have a similar thing now - the heat from the March-June warm up below the surface has to get washed out. The La Nina last year was also weaker than 2010-11. So even though the subsurface is tracking like a colder 2011-12 event, the surface is tracking like a warmer 2011-12.

No real change at the surface from August-September. The subsurface in 2011 is an excellent match to 2021 for January-September. So it's likely the subsurface will stop cooling and flip to warming in October or early November, like 2011. This is the subsurface (100-180W, 0-300m down) comparison. Jan Feb Mar Apr May Jun Jul Aug Sept2011 -1.27 -0.22 0.50 0.58 0.47 0.39 0.06 -0.54 -1.012021 -1.02 -0.83 0.27 0.60 0.65 0.31 -0.40 -0.83 -1.27 October 2011 dropped to -1.26 in October, then reversed in November. It cooled again briefly in Dec-Jan, but October was the peak.

September finished slightly wetter than average here with the rains yesterday. Tentative precipitation analogs for Albuquerque, based on July-Sept objective matches are 1950, 1954, 1974, 1983, 2004 as a blend. That's a pretty mixed period for Oct-May - with some dry and some wet months. Matching on the wet September definitely moved the matches to wetter for Oct-May. The GFS still has a major low south of Kamchatka on 10/2 in the evening. Have to watch 10/19-10/23 in our area for something pretty big. That's actually pretty close to one of the recurring wet-periods locally (10/18 would be 46 days or so after the remnants of Nora, which followed the mid July and early June rains, and so on). The rain yesterday also followed at a 46-day lag from the mid-Aug and early July and late May rains here. The WPO doesn't flip phases super often, so could be in for a good pattern for a while. The historic snows last October down to Mexico were also fairly close to the 10/19-10/23 time-frame, but the setup looks pretty different even this far out.

The subsurface for 100-180W at the equator, 0-300m fell to -1.27 in September. That's colder than I expected. The simplest recent match that looks like the Canadian outlook is 2007, 2010, 2011, 2011 for July-Sept subsurface readings. (year, july, aug, sept) 2011 +0.06 -0.54 -1.01 2011 +0.06 -0.54 -1.01 2010 -1.36 -1.74 -1.93 2007 -0.48 -0.68 -1.03 Avg -0.43 -0.88 -1.25 2021 -0.40 -0.83 -1.27 The correlation for 1979-2020 September subsurface readings and winter SSTs in Nino 3.4 is very strong. Near 0.8 for r-squared. But it is still highly variable. When I ran it using the -1.27 figure, I got 25.54C as the winter estimate. But...the errors historically imply it's 25.54C, +/-0.75C at 90% confidence in practice. In other words, running "warm" of the 25.54C is probably feasible. Last year's actual winter reading ran "cool" of the 25.80C the September subsurface projected as an example. The average error from plotting September subsurface v. Nino 3.4 at the surface in winter is plus or minus 0.4C. Solar activity was over 51 sunspots for September - highest monthly since March 2016. So far, we're off to a devastating start for snow.

Don't think the new Canadian has the right strength (too cold) for the La Nina, but it does have a real -PDO look. Way more than the last run did. The new temperature outlook for October is pretty close to the winter analogs I have with a +WPO - I did add one degree because the average time is 1988.

Still there. Time-frame on this is 6 pm Saturday. So 10/2 evening +17-21 days. Roughly 10/19-10/23 or 10/20-10/24 for a storm for NM & CO. Roughly speaking, Kamchatka functions as the Rockies in the Bering Sea Rule. So the storms south/east of Kamchatka can pull in Gulf of California and/or Gulf of Mexico moisture depending on the path they take.

PDO was positive in both 1995-96 for Nov-Apr and 2009-10. It was +0.59 in January 1996 with the blizzard. https://oceanview.pfeg.noaa.gov/erddap/tabledap/cciea_OC_PDO.htmlTable?time,PDO I do think it will be more negative. But more "weakly positive" than truly negative. October in my analogs was a split decision: 2017 and 1961 had +WPO, 2001 and 2020 had -WPO conditions, with 1974 sort of near normal. If you blend 1961, 2017 (x2 each) with 1974 and then add a degree for how old those years are, it does look pretty similar to October on the CFS. Do want to see the Canadian, it's usually better. For what it's worth, all five of the years I like have the WPO positive in November. We'll see how that goes. It's probably not going to be as active in the late hurricane season without cold dumping into the Plains / Gulf like if the WPO is negative in October. The ACE was pretty high in 2001 & 2020 late - 46 & 75 respectively (22 is average), while the others are lower - 1961 (51.5), 1974 (2.6), 2017 (20.5). I'm expecting 30-40 from 10/1-end of season. You guys want 35+ ACE after 10/1 to top 150 for the season. That's a good snow signal for the NE in La Ninas.

Final SOI matches to July-September are in (broad) agreement with the CFS for October. SOI July Aug Sept 1938 17.2 12.4 7.6 1974 11.1 6.3 12.2 1981 8.1 5.1 6.4 1996 6.6 4.8 6.9 1998 12.8 9.7 12.1 2011 9.1 2.6 11.1 Blend 10.8 6.8 9.4 2021 16.3 4.4 9.2 A blend of 1938, 1974, 2011 is basically an ideal/canonical +WPO look for October. Matches fairly well to September for an analog based on three numbers and nothing else.

There are some mixed signals going into this winter. More than last year in some ways. The lowest Arctic sea ice extents in September correlate pretty well since the data starts to the biggest +WPO winters. That's a horrible/strong warm signal for most of Canada and the eastern US. But with more sea-ice extent this September v. 2020 you can already see the WPO behaving differently. It was very negative last October (a very cold signal for the Plains), while the temperature profile on the CFS is almost ideal positive (of course the CFS is terrible at predicting October I find). Generally you want upper level low pressure (blue) by 180W, 60N to be north of upper level high pressure (red) by 180W, 30N to get the +WPO sign from eyeballing it. WPO tends to not flip super often. So +WPO October is usually a cold signal for the West in Nov-Dec, a wet signal in the Plains in November, and a warm signal for the east through at least December. You can see what last year looked like when it was negative. For what it's worth, you're not really "supposed" to get huge +WPO readings with La Nina - last year was the first to have it so consistently positive since 1950 (only La Nina over +1.00 in Dec-Feb). Part of why I liked 2007-08 is it was the strongest recent La Nina with pretty consistently positive WPO readings. I think Joe Bastardi and his crew expect the WPO to go negative in December and that's part of why they expect a colder outcome than I do for the East. Some of the analogs I have do show that, but not the recent years.

The PMM warming this month makes me think the cold will have much more trouble getting into Nino 4 than last year. A lot of the cold-ENSO winters in the 1959-1967 period are pretty cold around 120W at the equator and then very warm in the North Pacific. Those years are pretty interesting winters, also a lot of nasty Gulf Hurricanes and similar features. The hurricane season put up 75 ACE 10/1-11/30 last year (3rd highest since 1931). Don't really see us getting particularly close to that in 2021. After Sam finally dies, could be quiet for a bit. Very unlikely to get a four/five combo in November two years in a row. For reference, these are the biggest October & Novembers for ACE: 87.8 (October 1878) 71.0 (November 1932) Highest Oct-Nov ACE since 1850 is 95 in 1878. The last ten La Ninas (2020, 2017, 2016, 2011, 2010, 2008, 2007, 2005, 2000, 1999) average only 35 ACE (+a bit more December). The 30-year average is 22 for 1981-2010. I kind of look at 145 as a good guess for now. 110 through 9/30 and then 35 more? The pattern should shift to somewhat west of what it was last year for cold dumps if the ACE drops from ~180 to ~145 going into winter. https://psl.noaa.gov/gcos_wgsp/Timeseries/Hurricane/hurr.atl.ace.data

https://www.accuweather.com/en/winter-weather/accuweathers-2021-2022-us-winter-forecast/1022887 As Paul Pastelok said in the earlier link, the Accuweather winter outlook is out today (9/29). Some things are similar to what I have. Some stuff I look at locally makes me a little skeptical of a dry winter out here despite La Nina. Was amused to see they had a wet winter here. I don't buy ~130% of normal here like he has though.

The higher the ACE the more likely it is the entire West has heat and dryness in a La Nina. Not just part of the west seeing one or the other, or just the Southwest - the whole West. It becomes close to a guarantee somewhere between 160-200 ACE I find. Last year was 180, and most of the west (TX, NM, CO, WY excluded where it was fairly average to cold for temps, and varied for precip) was pretty warm and dry. There is ACE inflation though via measuring techniques, so I treat last year like a 165-170 year. The highest ACE La Ninas all feature 3-6 month periods with literally no rain or snow in places in the Southwest - extraordinary dryness even here. I've also mentioned that in NYC/Philly/Baltimore the La Ninas with over 150 ACE are close to a coin flip for a good snow year (+20% or more) while all other La Ninas have close to 0% odds of a snowy winter. Look at your high ACE years for snow in the NE with La Ninas: 1933-34, 1995-96, 2010-11, 2017-18, 2020-21 are all in there as examples.

Ruh Oh. The GFS still has a very powerful low in same spot as 2/24/2021. That spot, +17-21 days is trouble for New Mexico and Colorado storms. Should be something pretty big coming through in that period. 3/13 was the Rockies blizzard right? You can see the +17 to +21 days works pretty well from that spot.

I don't know if it is of any use, but for my outlook this year I am including a tele-connection table to lay out the patterns. I partly did it because I think there are two pretty violent pattern shifts in mid-November and mid-February in the upcoming cold season. Been struggling with the weighting for November in particular. But basically it will lay out my expectation for WPO, PNA, AO, NAO for Nov-Mar. October is going to be a little bit nutty with the re-curving typhoon, rapid recent SOI changes, and then the GFS showing a very deep low off the southern Kamchatka tip. It's the same spot as the 970 mb low 2/21/2021 that preceded the March blizzard out here. https://en.wikipedia.org/wiki/March_2021_North_American_blizzard The Bering Sea Rule tends to translate those lows in those spots to "Albuquerque Lows" in 17-21 days. Locally, most of the tele-connections are broadly useless as correlations to long-term temperatures in most months under 0.04 (r-squared). But the January-April period does respond more to the NAO and WPO locally, so I do look at them for that period here. The big late September NAO crash is interesting - you might want to look at the periods that follow given your region. I'm fairly confident that the "look" that often precedes severe cold in the Plains in February is going to show up again in November. Since at least the late 1970s, that seems to be a +WPO, +AO, +NAO look in November. That's there in 1978, 1992, 1993, and 2020, with several other less severe outbreaks are similar.

The CFS may be off it's rocker, but it has a very wet October in the Southwest. We're heading into a cold-ENSO winter. But we also should have a pretty high ACE value. It's not real common for a wet October + big ACE combo to happen down here, especially with a cold ENSO look. I'm real curious to see what happens in the Atlantic - 2020 October-November ACE was third highest since 1931, behind 1932 and 2016. Unheard of to be as active as 2020 was late two years in a row. So ACE might only hit 155 or 160 or something. My weighted analogs of 1974 and 2017 as a blend might actually be about right - 150 ish ACE, with 1.00 inch of rain in October. Some of the moisture shown is the CFS not understanding a lot of the incoming rain will fall 9/30 in actual American time and not UTC. But it probably does see an actual wet month even ignoring that issue.

This is my take on why this event won't catch up or surpass last year at the surface. In 2017, Nino 3.4 was well behind the prior year cold. Unlike this year though, it was much colder y/y in Nino 1.2 and 3 by this time. We're running warmer each week in all zones for at least two months now.

Pending the exact timing of the heavy rain for New Mexico & Texas on 9/30-10/1, the strong Jun-Aug 1974 match to June-Aug 2021 for precipitation looks like it will continue into September 2021. Will be curious to see how that goes going forward, since the Summer was also similar to Jun-Aug 2017, which was very dry here in winter, while 1974 was very wet. I'm including 1961 as an analog as it is almost like a split the difference between 1974 and 2017 for winter. Both 1974 and 2017 are weak La Ninas following La Ninas with the QBO in the right phase. I find low solar activity yields different precipitation patterns in Spring/Fall then high solar activity nationally. We're getting real close to my threshold for "high solar" in individual months now, with ~50 sunspots looking likely for September, most since 2016 for a single month. For the Southwest, high solar is a pretty strong wet signal in March. But you need around 55 sunspots annualized for the "high" solar activity to show I find. Still only at about 25 annualized if September does finish around 50. Odds of getting above the high solar threshold are increasing though.

The GFS has a 980 mb low south of the tip of Kamchatka on 10/3. It's been there, or similar for a few runs now. That's probably a good snow event for at least the higher terrain of NM and CO if that verifies in a few days. Would be 10/20-10/24 if the GFS timing is right.