2025-2026 ENSO

[A-L-E-K]

4 minutes ago, GaWx said:

This is a good post imho and mirrors my general thinking:
 

ready 2 b buried

[snowman19]

I’m not sure we can be confident on a west coast ridge for mid-late December. Paul Roundy has been vehemently disagreeing and thinks the subseasonal forcing supports -PNA/SE ridge after early December. When he talks you have to listen, the guy basically wrote the book on the book on the MJO (Roundy MJO plots)

[GaWx]

 Today’s Euro Weeklies 10 mb 60N mean zonal wind isn’t as weak as recent runs:

Today’s run (11/19):

 

Yesterday’s (11/18):

 

Does anyone else see what I’m referring to? I’m not just talking about whether it actually reverses. I’m talking more about the period afterward.

[MJO812]

10 minutes ago, snowman19 said:

I’m not sure we can be confident on a west coast ridge for mid-late December. Paul Roundy has been vehemently disagreeing and thinks the subseasonal forcing supports -PNA/SE ridge after early December. When he talks you have to listen, the guy basically wrote the book on the book on the MJO (Roundy MJO plots)
 

 

 

 

 

 

 

 

 

He is a smart guy but he has been wrong in the past.

[GaWx]

 Today’s Euro Weekly 2m temp anomalies vs yesterday’s run:

Dec 1-7: ~same

Dec 8-14: similar for most/slightly stronger cold in Lakes region

 

Dec 15-21: similar for most/slightly colder NNE

Dec 22-28: similar for most/slightly colder NE/slightly less cold Lakes region:

[brooklynwx99]

the weeklies should not run every day. so stupid

[GaWx]

9 minutes ago, brooklynwx99 said:

the weeklies should not run every day. so stupid

 Why not? Other long range models run daily like GEFS. Long range should always be taken with a grain, regardless, due to high levels of forecast uncertainty. But why not run them daily since despite unreliability they can at least hint at potential trend changes past 2 weeks. The EW have been halfway decent imho. For one thing, they had very early hints about the upcoming very weak SPV. For another, they’ve done pretty well with hints about general levels of Atlantic tropical activity weeks out.

[MJO812]

14 minutes ago, brooklynwx99 said:

the weeklies should not run every day. so stupid

Snowmap looks great for the east. 

[snowman19]

1 hour ago, GaWx said:

 Today’s Euro Weekly 2m temp anomalies vs yesterday’s run:

Dec 1-7: ~same

Dec 8-14: similar for most/slightly stronger cold in Lakes region

 

Dec 15-21: similar for most/slightly colder NNE

Dec 22-28: similar for most/slightly colder NE/slightly less cold Lakes region:

Huh. So I guess they’re actually not showing “extreme cold” like I just read on twitter. Man oh man, you have to be really careful who you follow there 

[MJO812]

18 minutes ago, snowman19 said:

Huh. So I guess they’re actually not showing “extreme cold” like I just read on twitter. Man oh man, you have to be really careful who you follow there 

No one said " extreme cold " but you said warm and thats not going to happen .

[brooklynwx99]

26 minutes ago, snowman19 said:

Huh. So I guess they’re actually not showing “extreme cold” like I just read on twitter. Man oh man, you have to be really careful who you follow there 

honest question, why are you even on twitter? I avoid twitter like the plague

there are enough knowledgeable people here

[snowman19]

24 minutes ago, MJO812 said:

No one said " extreme cold " but you said warm and thats not going to happen .

I wasn’t talking about on here you bozo. Did you even bother to read what I said or you just saw that I dared to say “not extreme cold” and you saw red. Oh wait…..you never see red

[MJO812]

18 minutes ago, snowman19 said:

I wasn’t talking about on here you bozo. Did you even bother to read what I said or you just saw that I dared to say “not extreme cold” and you saw red. Oh wait…..you never see red

[FPizz]

24 minutes ago, MJO812 said:

What a miserable person.  Sad.

 

[donsutherland1]

7 hours ago, GaWx said:

 Thanks Don,

 I see your point about the unpredictability of upcoming NE snow. Moreover, this thread isn’t strictly about NE snow (as you know). It’s of course also about NE and other areas’ temperatures, wintry precip in other areas, and many other things.

 Wintry precip, which is usually more variable/localized than the cold influence of Arctic airmasses, is thus often less predictable than temperatures. Therefore, regarding the potential lagged effects of an SSWE, I’m guessing that temperatures in the NE US as well as for other areas for whatever period would be less unpredictable than snowfall. From what I’ve learned, there’s a significantly better chance than normal for a multi week long period of cold domination in the E US usually starting 2-3+ weeks after an SSW. More often than not the cold will appear in the E US. Most likely that would naturally mean increased wintry precip in parts of the E US, but where is the question?

 Especially if there’s a decent sized sample, I do like to look back at specific cities’ stats (temps and wintry precip) to give me some idea of the potential, regardless.

I used the NE as an example, because it seemed that a lot of the commentary had been focused on the NE U.S. 

[George001]

4 hours ago, snowman19 said:

I wasn’t talking about on here you bozo. Did you even bother to read what I said or you just saw that I dared to say “not extreme cold” and you saw red. Oh wait…..you never see red

Yes because being rude is a great way to get your point across

[bncho]

chill yall. this is a thread to talk about ENSO, not a thread to belittle people because of their biases warm/cold. jeez

[snowman19]

From Dr. Simon Lee, for those who don’t know, he’s a college professor of meteorology and an expert on the stratosphere, has written many papers on it. Here’s what he has to say:

[BlizzardWx]

I saw this graphic on X from Eric Webb showing the cooling lower stratosphere in the tropics. It seems the trend in strengthening the MJO is likely related to models catching on to the effects of the stratospheric warming as well as the final warming at the south Pole (strengthened Brewer Dobson circulation). Perhaps this is what will finally allow us to see a robust MJO through phases 7-8-1. 

[PhiEaglesfan712]

11 hours ago, FPizz said:

What a miserable person.  Sad.

 

The start year for this has to be 1951 because the November 25, 1950 record is just about impossible to beat out. Atlanta got to 3 degrees that day, and the places where the record low would be got to below 0.

[BlizzardWx]

Some guidance wants to bring one of the PV lobes into North America. The 06Z AIFS does this near the end of its run, and unsurprisingly is building some very cold air at the surface at this same time. Obviously that is what we would want to see heading into December. 

[MJO812]

18 minutes ago, BlizzardWx said:

Some guidance wants to bring one of the PV lobes into North America. The 06Z AIFS does this near the end of its run, and unsurprisingly is building some very cold air at the surface at this same time. Obviously that is what we would want to see heading into December. 

Looks like a cold end to November. A huge change from when the models showed a mild end.

 

[40/70 Benchmark]

16 hours ago, snowman19 said:

I’m not sure we can be confident on a west coast ridge for mid-late December. Paul Roundy has been vehemently disagreeing and thinks the subseasonal forcing supports -PNA/SE ridge after early December. When he talks you have to listen, the guy basically wrote the book on the book on the MJO (Roundy MJO plots)
 

 

 

 

 

 

 

 

 

This is my thinking, as well...but I am nervous.

[40/70 Benchmark]

16 hours ago, GaWx said:

 Today’s Euro Weeklies 10 mb 60N mean zonal wind isn’t as weak as recent runs:

Today’s run (11/19):

 

Yesterday’s (11/18):

 

Does anyone else see what I’m referring to? I’m not just talking about whether it actually reverses. I’m talking more about the period afterward.

This trend is more in line what with my thought process. I anticipate a more rapid recovery of the PV than some guidance has implied due largely to how I feel the stratosphere will evolve mid season (mid January reflection event).

[EasternLI]

Gotta watch this. If you pop a poleward Scandinavian ridge here that suggests further damage to the PV sometime in December.

[michsnowfreak]

52 minutes ago, PhiEaglesfan712 said:

The start year for this has to be 1951 because the November 25, 1950 record is just about impossible to beat out. Atlanta got to 3 degrees that day, and the places where the record low would be got to below 0.

Not sure if it matters but those were 500mb temps, not surface temps.

That said, November 1950 saw an incredible shift in temps. At Detroit, November 1st saw the all-time November high temp of 81°, to this day the only time 80 has been seen in November...then 7° on November 24th.

[donsutherland1]

There have been some subtle shifts in the guidance. The combination of subtle shifts and long timeframes can lead to big changes. But the timeframe involved is speculative and skill scores at that timeframe are essentially non-existent. 

What remains extremely likely is that a sudden stratospheric warming event (SSWE) is imminent. Zonal winds will slacken dramatically during the next 5-7 days. A full reversal can't be ruled out.

There is typically a lag of 10-30 days for the impact of an SSWE to propagate to the troposphere. So, even as a cold shot appears increasingly likely from the Great Lakes Region to the Northeast to close November, that cold shot will almost certainly not be the result of the imminent SSWE. What happens with the polar vortex (split and location of the pieces) will be crucial. 

For now, things still appear on a path toward an EPO-/WPO-/AO-/PNA- pattern development. Initially the most significant cold appears likely to dump into the Plains States before pushing eastward. The Great Lakes Region still seems primed for a possible multi-week period of below normal temperatures coupled with above normal precipitation. That should lead to an increase in snowfall totals in such cities as Chicago, Detroit, Windsor, and Toronto. 

Pieces of the cold should begin to bleed into the East, but perhaps after the first 7-10 days of December.

If things evolve along this baseline scenario, the December 10-25 period might see the coldest anomalies relative to normal for such cities as Chicago, New York, Philadelphia. The Southeast could see some intrusions of cold, but the PNA- could promote an unwelcome and persistent tendency for SE ridging. Newer guidance suggests an increased probability of a negative NAO, so that could flatten the SE ridge at times. This is my baseline thinking.

IMO, the Week 3-4 CPC Outlooks capture the temperature idea of kind of pattern I expect to prevail during the first half of December. 

Despite social media chatter 1983-style Arctic outbreaks, a lot would need to change for such an outbreak to become likely. Currently, the Northern Hemisphere's cold pool is much smaller than it was at this time in 1983:

2025:

1983:

 

In the very long range, some of the subtle shifts in the teleconnections e.g., dissipation of the WPO-, could translate into the trough's migrating back to the West and a Southeast Ridge reviving in the closing week of December. That's not shown on the weekly ECMWF guidance. But the December 22-29 period's 500 mb forecasts should be monitored for hints of change. It should be noted that neither the MJO nor teleconnections can be forecast with skill at such a forecast horizon.

In sum, wintry opportunities should increase in December, first in Plains States and Great Lakes and then farther East. The Great Lakes Region and Ohio Valley look primed for above normal snowfall during December. The Southeast could have the most difficult time seeing the cold try to gain traction, but some cold shots should eventually break through. The closing week of December looks uncertain. Much depends on how the SSWE's impacts will evolve and other variables that cannot be forecast with skill at that range.  Typical SSWE lags would argue that the breakdown in the pattern might occur later. Then there's always the wild card of additional warming events.

[GaWx]

14 hours ago, FPizz said:

What a miserable person.  Sad.

 

 

3 hours ago, PhiEaglesfan712 said:

The start year for this has to be 1951 because the November 25, 1950 record is just about impossible to beat out. Atlanta got to 3 degrees that day, and the places where the record low would be got to below 0.

 

2 hours ago, michsnowfreak said:

Not sure if it matters but those were 500mb temps, not surface temps.

That said, November 1950 saw an incredible shift in temps. At Detroit, November 1st saw the all-time November high temp of 81°, to this day the only time 80 has been seen in November...then 7° on November 24th.

Based on H5 height comparisons (not H5 height anomaly comparisons), I strongly doubt that H5 temps on 11/11/2025 were as cold as those of 11/26/1950:

11/26/1950 0Z: N NC ~520 dm per upper right map

 

11/11/2025 6Z: N NC 528 dm

 

 However, in terms of H5 temperature anomalies for any date in Nov back to 1950, I feel it’s likely because NC H5 ht anomalies on 11/11/2025 were as low as -45 dm vs 11/26/1950’s lowest being ~-41 to -42 dm per the comparisons of these two maps. Had the 11/11/2025 pattern instead occurred 2 weeks later, I believe it likely would have broken the Nov H5 temp. record.

 Keep in mind that H5 heights are directly related to air temps from H5 down to the surface.

[MJO812]

[GaWx]

Today’s GEFS gets to phase 7 a day earlier than yesterday’s (11/28 vs 11/29) and three days earlier than the run from 2 days ago.

 The 11/19/25 Euro-ext gets it to phase 8 ten days earlier (12/5) than the prior run (12/15):

Prior run (11/18/25):