2025-2026 ENSO

[anthonymm]

5 hours ago, MJO812 said:

All the ensembles bring down the cold after the first week.  No clue what the panic is right now.

Because that's too far out. Underestimate the SE ridge at your own peril.

[anthonymm]

3 hours ago, GaWx said:

DJF MJO last 15 winters (2010-1 through 2024-5): # of days each phase

*7: 286 days from 58 phase 7s or 4.9 days/phase

*8: 95 days from 34 phase 8s or 2.8 days/phase

1: 76 days from 24 phase 1s or 3.2 days/phase

2: 96 days from 23 phase 2s or 4.2 days/phase

3: 167 days

4: 173 days

5: 212 days

6: 249 days

———————

  Per the above data, the # of phase 8 days for the last 15 winters, combined, has been only 1/3 the # of phase 7 days. This was due to a combo of much fewer phase 8 periods than phase 7 periods (34 vs 58) and much shorter avg. duration for 8 vs 7 (~3 days vs ~5 days). So, there sometimes is a struggle in going from phase 7 to 8. The # of combined 8-1-2 days has been ~# of phase 7 days, alone!

 The coldest E US phases have been 8, 1, and 2 while the warmest have been 4-6 (see bottom). The # of phase 8-1-2 days, combined, has only barely been higher than the # of phase 6 days, alone!

 So, as we look at Dec MJO progs, keep in mind the relative difficulty in getting as many phase 8 days (as well as each of phases 1 and 2, for that matter) as phase 7 days (if any at all). Just because models suggest a 2+ week long phase 7 is very likely doesn’t necessarily mean the durations of each of phases 8, 1, and 2 immediately following will be anywhere near as long, if they even occur.
 

 Here are the 10+ day long phase 7s since 2010-1 along with the subsequent phase 8-1-2:

- 1/14-30/13: 17 days followed by a combined 15 days in 8-1-2

- 2/19-29/2016: 11 days followed by a combined 10 days in 8-1-2

- 2/2-18/2018: 17 days followed by a combined 10 days in 8-1-2

- 2/7-21/2021: 15 days followed by 0 days in 8-1-2 and instead a combined 11 days in 6-5-6-7

- 12/19/2021-1/9/2022: 22 days followed by only 4 days in phase 8 before going back to 7; phases 7-6-5-4-3 then dominated the next 3.5 weeks.

- 1/1-10/2023: 10 days followed by a combined 9 days in 8-1-2

- 2/16-28/2023: 13 days followed by 1 day in phase 6 and then right back to phase 7 for 5 more days…so, 19 days in phase 7 for all practical purposes…followed by a combined 19 days in 8-1-2

- 1/28-2/6/2024: 10 days followed by 2 days in phase 6 and then right back to phase 7 for 10 more days….so, 22 days in phase 7 for all practical purposes…followed by only 1 day in phase 8, which was then followed by a combined 31 days in 7-5-6-7-3-4-5-6

———————

 Analysis of the above:

- Much more frequent 10+ day long phase 7 last 5 winters with 5 of them vs only 3 during the previous 10 winters!

- The combined 8-1-2 duration was never longer than the prior phase 7 length (using the “for all practical purposes” phase 7 length in two cases).

- Of the 8 long duration phase 7s, two (25%) of the following 8-1-2 periods lasted a notable length of 15-19 days and three (38%) lasted a mediocre 9-10 days. However, the other three (38%) were only a minuscule 4 or fewer days long (4, 1, 0) and these were all within the last 5 winters.

- So, whereas there’s a decent chance to get a higher end duration of 15-19+ days in 8-1-2 following the upcoming 7, the chance doesn’t appear to be very high and the chance of getting only a very disappointing short period is probably at least about as high.

- Thus, recent history tells us that the upcoming 2nd half of Dec MJO is practically un-forecastable as of now with dominance by the often cold 8-1-2 about equally as probable as a feared hardly any 8-1-2.
 

@donsutherland1@bluewave
———————

Daily MJO:

https://www.bom.gov.au/clim_data/IDCKGEM000/rmm.74toRealtime.txt

Basically whichever way you slice it the atmosphere is biased against cold and snow in the east now.

[anthonymm]

2 hours ago, Krs4Lfe said:

One thing that I don't like is the lack of cold and snowstorms over CONUS thus far. I remember mentioning this in December 2023 and December 2024. Even years that were not good for us (2019,2020,2023) still had way more snowstorms and cold thus far. In many years, the snowstorms began as early as October, but even if it didn't begin in October, it began in November, and there would be a few large ones and several smaller ones as we neared December. Fall 2023, Fall 2024, and Fall 2025 have been virtually devoid of snow across CONUS outside of a few mountain ranges in New England and parts of the Great Lakes (and even then, that's been pretty muted). Part of this is likely due to the warmth in Canada, as that moderates temps across the northern tier, making most of their precipitation rain thus far. Ideally, you like to see a quick start to the season in October or November across the Plains and Upper Midwest, but like Fall 2023 and Fall 2024, that has been almost entirely absent this season. Snow begets snow, and cold begets cold. When that is absent from nearly the entirety of the US, with December right around the corner, that's never a good sign imo. I raised these points last November and December as well. 

100%. It is so bizarre to see like none of the conus with snow cover this late into November. Can't be a good sign. Even if the cold shot early dec bleeds east like the weenies think it'll quickly moderate anyway from the lack of snowcover. Not gonna cancel winter on Nov 23 but i wouldn't be surprised if this is another stinker. 

[Krs4Lfe]

8 minutes ago, anthonymm said:

100%. It is so bizarre to see like none of the conus with snow cover this late into November. Can't be a good sign. Even if the cold shot early dec bleeds east like the weenies think it'll quickly moderate anyway from the lack of snowcover. Not gonna cancel winter on Nov 23 but i wouldn't be surprised if this is another stinker. 

Yeah the past two fall seasons featured the Same problem. Very strange, cant be a good sign. It’s crazy how 2019 winter (which was seen as almost a dud at the time because NYC only had 20”, is actually better than almost all other winters we have seen in the past 7 years). Thinking this is probably the new normal. 

[GaWx]

Today’s Euro Weeklies aren’t what you want to see if you don’t want them to be warmer than yesterday: the most intense cold on the run is W and SW of Chicago and perhaps near ME. I personally hate them because the colder the better and I hate sweating in winter when I take my walks. Note that the warmest anomalies in the US are in the deep SE:

Dec 1-7: very slightly warmer/strong SER:

 

Dec 8-14: slightly warmer/stronger SER lingering:

 

Dec 15-21: warmer/SER won’t give up

 

Dec 22-28: SER finally weakened but slightly warmer NE vs yesterday

 

Dec 29-Jan 4: SER staying weak but slightly warmer NE vs yesterday:

[anthonymm]

8 minutes ago, Krs4Lfe said:

Yeah the past two fall seasons featured the Same problem. Very strange, cant be a good sign. It’s crazy how 2019 winter (which was seen as almost a dud at the time because NYC only had 20”, is actually better than almost all other winters we have seen in the past 7 years). Thinking this is probably the new normal. 

I think so too man. We're not going back. I can see NYC settling on a 15ish inch mean for good now, absent a volcanic eruption like bluewave said.

[GaWx]

Check this out regarding 8+ day long MJO phase 8 since 1974-5:

Fifteen 8+ day winter phase 8 periods back to 1974-5 in # of days, amp, (practical) # days of preceding phase 7; Balt snow/temps:

-1/19-31/75: 13; amp 2.1; 3; 3.5”/MA

-12/19/75-1/5/76: 18; amp 1.0; 2; 0.5”/B

-1/27-2/3/76: 8; amp 2.3; 4; 1.3”/N

-2/8-15/76: 8; amp 1.8; 4; T/A

-2/20-28/1978: 9; amp 1.8; 3; T/B

-2/17-26/82: 10; amp 1.1; 0; 5.2”/N

-1/21-30/83: 10; amp 1.5; 0; T/N

-1/12-22/85: 11; amp 1.6; 9; 2.8”/MB

-12/31/87-1/7/88: 8; amp 1.2; 6; 4.3”/MB

-2/21-29/88: 9; amp 3.2; 5; T/B

-12/9-18/89: 10; amp 1.1; 4; 5.5”/MB

-1/2-9/97: 8; amp 1.9; 6; 2.4”/MA

-2/16-24/99: 9; amp 2.1; 4; 0.6”/B

-2/7-17/10: 11; amp 1.7; 16; 19.6”/MB

-2/15-23/19: 9; amp 1.9; 1 (5); 4.5”/A

———————

Analysis of above:

- The # of days of phase 7 preceding these long phase 8 periods have a large majority of the time been <7 days (counterintuitive?).

- Consistent with the great post today of @bluewave, look how sharply the frequency has dropped off: 5 in the 2nd half of 70s, 6 in the 80s, 2 in the 90s, none in the 00s, 2 in the 10s, and none in the 1st half of the 20s.

-So, from 1974-5 through 1989-90, there was an avg. of 0.7/winter. But since 1990-1, there has been a mere 0.1/winter or only 1/7 the frequency!

-But when they occur, they still have been leaning pretty hard on snow and cold based on Baltimore:

Temps:
MA: 2

A: 2

N: 3

B: 4

MB: 4

 - So, twice as many cold as mild

 - Total snowfall 50.2” over these 151 days, which means an average of 0.33” per day. That’s almost 150% of the Jan-Feb 1974-2025 average daily snow of 0.23”.

- So, although they’ve been much harder to come by, lengthy phase 8 periods remain highly desirable for a winter lover in the E US.

@donsutherland1

*Edit 6:30PM: On average, the <1.8 median amplitudes of these long phase 8 periods have been colder and snowier than the 1.8+ amps:

 There were 7 phase 8 amps <1.8:

-4 of the 7 lower amps were the only four MBs while all 4 of the A to MA were when the amp was 1.8+.

-All but one of the 4”+ snows were during an amp <1.8.

[MJO812]

1 hour ago, GaWx said:

Today’s Euro Weeklies aren’t what you want to see if you don’t want them to be warmer than yesterday: the most intense cold on the run is W and SW of Chicago and perhaps near ME. I personally hate them because the colder the better and I hate sweating in winter when I take my walks. Note that the warmest anomalies in the US are in the deep SE:

Dec 1-7: very slightly warmer/strong SER:

 

Dec 8-14: slightly warmer/stronger SER lingering:

 

Dec 15-21: warmer/SER won’t give up

 

Dec 22-28: SER finally weakened but slightly warmer NE vs yesterday

 

Dec 29-Jan 4: SER staying weak but slightly warmer NE vs yesterday:

Are they even useful anymore ? Even if they showed cold they shouldn't come out everyday. 

We have to be patient 

[MJO812]

47 minutes ago, anthonymm said:

I think so too man. We're not going back. I can see NYC settling on a 15ish inch mean for good now, absent a volcanic eruption like bluewave said.

Another bold post 

[JACKASS]

17 minutes ago, MJO812 said:

Are they even useful anymore ? Even if they showed cold they shouldn't come everyday. 

We have to be patient 

LOLOL

[michsnowfreak]

2 hours ago, GaWx said:

Today’s Euro Weeklies aren’t what you want to see if you don’t want them to be warmer than yesterday: the most intense cold on the run is W and SW of Chicago and perhaps near ME. I personally hate them because the colder the better and I hate sweating in winter when I take my walks. Note that the warmest anomalies in the US are in the deep SE:

Dec 1-7: very slightly warmer/strong SER:

 

Dec 8-14: slightly warmer/stronger SER lingering:

 

Dec 15-21: warmer/SER won’t give up

 

Dec 22-28: SER finally weakened but slightly warmer NE vs yesterday

 

Dec 29-Jan 4: SER staying weak but slightly warmer NE vs yesterday:

The last week of November actually got colder on the weeklies. And has for several days. Though I know youre concentrating on December. I know the Mid-Atlantic may not like it but those weeklies with the cold to the Nw and warmth to the SE would be a great storm track for the Great Lakes.

[EasternLI]

3 hours ago, bluewave said:

Yeah, this is what I have been discussing. The rapid warming of the WPAC tropical SSTs near the near the Maritime Continent has been stalling the MJO in the warmer storm track and background temperature phases.

So the MJO progression tends to linger longer in the 4-7 phases and spend less time in phase 8.

This is why January 2022 was the last time that the RMM and VP anomaly charts were both solidly in Phase 8.

From March 2022 through the winter of 2024-2025 the few MJO 8s per the RMM charts had lingering forcing in phase 5-7 regions. So we didn’t fully realize the MJO 8 pattern which we last had in January 2022.

Many times the models try to rush the progression through phase 8 and it gets delayed and or weakened the closer in time we get to the forecast period.

This is what is shown when we subtract the last 16 years from the previous 16 years. You can see the stronger forcing closer to phases 6-7 where the warmest  SSTs on earth near +30C are found during the winter. This +28C +30C warm pool has been steadily expanding across that region.
 

 

 

Nice post man. You know that I agree with this assessment. We've had some good chats about this occasionally in past years. It's a real factor and should be considered into the equation. Having said that. I don't think we should rush to judgement yet on this particular MJO event and I'll try to explain why. This event thus far has been driven to propagate eastward with CCKW's. Which operate due to different circumstances from the MJO and with much faster timescales. Since the beginning of this event really, they've been noticeable in the data and the models. I mentioned this phenomenon in a post here last month I think too. This is still the case on current runs. We've been seeing this alternating constructive and destructive interference cycling through the event as they do. Which is presenting itself as the loops around on the RMM charts we've been seeing. It was slowed, naturally, as it approached the La Nina state in addition to that as well. However, it seems to want to persevere on the longer range guidance. Regular ensemble runs (gefs/eps) don't run out far enough to capture the whole picture. What we've been seeing with those is an amplified trend when there is constructive interference. Mixed with other times where the signal almost vanishes when there is destructive interference from these CCKW's. The latest one is about to constructively interfere, which is offering some boost to the Phase 7 signal upcoming. Some here seem to be under the impression that the phase 8 attempt is within range of the current medium range ensembles. I think that is a mistake. Any signal giving that impression should be the current CCKW continuing to propagate through to the east. So what I think will happen, is that we will see the amplification into phase 7 as guidance is advertising. Followed by a degradation which will be denoted once again with the RMM chart doing a loop with the signal again. IMO the actual attempt for the push into phase 8 comes a little after that. With the next CCKW that should propagate through and is modeled to do so. If guidance is any indication, that should occur close to mid month in December IMO. Outside of the range of current gefs/eps runs. We'll probably see a more ambiguous signal until that time. Much like the later stages of the 12z GEFS posted right below. It could in fact fail and possibly for the reasoning that you've laid out very nicely here. Personally I think the jury is still out for this one, but that they will enter the building around mid December to prepare the verdict. Such as euro (and gefs for that matter) weekly data suggests. Today's euro weekly forecast at the very bottom. 

 

 

Today's Euro weeklies VP200 followed by U850:

[EastonSN+]

3 hours ago, anthonymm said:

Because that's too far out. Underestimate the SE ridge at your own peril.

Its the RNA pumping up the SE ridge, not the other way around.

[EastonSN+]

2 hours ago, anthonymm said:

I think so too man. We're not going back. I can see NYC settling on a 15ish inch mean for good now, absent a volcanic eruption like bluewave said.

The NYC average was 21.91 inches during the 30 year period from 1970 to 1999.

From 2020 to now the average is 15.84.

We are not far off. 

The average was 32.35 from 2000 through 2020. That has skewed the average higher as well as expectations.

 

[Maestrobjwa]

5 hours ago, anthonymm said:

Because that's too far out. Underestimate the SE ridge at your own peril.

Not that it would have to be correlation, but...last year was one year where if ya underestimated it you were right, lol

[40/70 Benchmark]

11 hours ago, donsutherland1 said:

The CFSv2 has now moved into the early stages of its skillful range. Its monthly forecast for December is below. 

I assessed this idea against the currently expected state of the teleconnections. ENSO was omitted, as the sample size became so small that is was useless (n=2).

Based on the expected predominant state of the teleconnections for December (WPO-/EPO-/PNA- and AO neutral) it appears reasonable. The AO should start negative but could go positive as December progresses based on the current guidance. The second half outcome will depend on whether or not the stratospheric warming event propagates to the troposphere to  promote a redevelopment or persistence of AO blocking. So, for purposes of conservatism, I treated the AO as neutral (monthly average above -0.50 but below +0.50)  for looking at the monthly CFSv2 idea.

Should an AO+ regime develop (SSW fails to propagate in a fashion that promotes AO blocking), warm anomalies could cover much of the Eastern Seaboard with the exception of central or northern New England and have the risk of spreading into at least the Ohio Valley and perhaps farther westward depending on the strength of the AO+. For now, this is an identified risk, but not the most likely outcome.

On the other hand, should strong AO blocking develop, most of the eastern half of the U.S. would likely see cold anomalies. This scenario would also have the highest probability of seeing a strong Arctic outbreak reach the East Coast. Given the present guidance, this seems to be less likely than an earlier breakdown of the AO-. But the stratospheric warming event is a wildcard and how such events ultimately play out over long timeframes is not a high-skill undertaking.

It should also be noted that teleconnections cannot be forecast skillfully beyond 10-14 days. 

All in all, the combination of the CFSv2 and teleconnections highlights the Great Lakes Region and Upper Midwest as having the greatest probability of experiencing cold anomalies. They also highlight the Great Lakes Region as having the highest probability of above normal monthly snowfall. 

As for my thinking using the framework I illustrated yesterday, I've highlighted what has changed in my thinking overnight in blue. The emergence of a neutral AO on the guidance was noted (there's a very large spread among the ensemble members).

No changes were made beyond December 10 as signals remain mixed and there remains no clear signal for a change. 

Gee, that December anomaly map looks familiar...where have I seen it before..maybe a few weeks ago?

Oh, yea....

[40/70 Benchmark]

I'll post a December update either late this week or next weekend.

[Daniel Boone]

26 minutes ago, 40/70 Benchmark said:

Gee, that December anomaly map looks familiar...where have I seen it before..maybe a few weeks ago?

Oh, yea....

Almost as if Analogues were fed into it to get that outcome, lol

[Krs4Lfe]

6 hours ago, GaWx said:

Today’s Euro Weeklies aren’t what you want to see if you don’t want them to be warmer than yesterday: the most intense cold on the run is W and SW of Chicago and perhaps near ME. I personally hate them because the colder the better and I hate sweating in winter when I take my walks. Note that the warmest anomalies in the US are in the deep SE:

Dec 1-7: very slightly warmer/strong SER:

 

Dec 8-14: slightly warmer/stronger SER lingering:

 

Dec 15-21: warmer/SER won’t give up

 

Dec 22-28: SER finally weakened but slightly warmer NE vs yesterday

 

Dec 29-Jan 4: SER staying weak but slightly warmer NE vs yesterday:

What looks like a cold pattern becomes nearly dominated by the SER as we move up closer in time. And any stronger storms will just pump up that ridge and we’ll have what we’ve mainly had for the past 7 years (warm cutters and then dry cold). Seems set in stone at this point.

[40/70 Benchmark]

41 minutes ago, Daniel Boone said:

Almost as if Analogues were fed into it to get that outcome, lol

I do some of that if I am no getting the look that I am striving for on the monthlies, but it's not based off of a model run.

[snowman19]

@Gawx Just looked at the new ECM zonal wind forecast, this is looking like almost a sure bet for a classic wave reflection event with a rapid recovery and strengthening of the SPV in December

[Stormchaserchuck1]

16 hours ago, 40/70 Benchmark said:

I'll bet you $100 I have a plowable event of 3" or greater by the end of the second week of December (14th).

I'm not going to bet you money, maybe another time, but I will bump this on Dec 14. I don't think you're going to get that snow. 

[snowman19]

@Stormchaserchuck1 It looks like the record +PNA streak is finally about to come to an end. The ensembles (EPS, GEFS, GEPS) have the most negative long range PNA forecast I’ve seen in a very long time….years in fact

 

[Stormchaserchuck1]

Dec 2021 was one of the strongest -PNA's.. what I see on models right now is a "moderate -PNA event" in early Dec. I also don't know that it sustains beyond like a week. We'll see. If it lasts into mid-December that would be a little different from what we have seen this year (where -PNA's last 7-10 days then go away). 
 

[PhiEaglesfan712]

49 minutes ago, Stormchaserchuck1 said:

Dec 2021 was one of the strongest -PNA's.. what I see on models right now is a "moderate -PNA event" in early Dec. I also don't know that it sustains beyond like a week. We'll see. If it lasts into mid-December that would be a little different from what we have seen this year (where -PNA's last 7-10 days then go away). 
 

December 2021 was a very warm December in the Eastern US (I think only 2015 was warmer). If we're not going to get any snow in December, then I hope it's a torch. At least it can come back to average at some point in the winter (like January 2022). The worst possible outcome is a cooler December with no snow (like December 2022).