2025-2026 ENSO

[stadiumwave]

 

Mean never gets to normal at all now throughout the forecast period. 

[michsnowfreak]

Weeklies below avg every week here. SE ridge definitely appears to have been overdone.

[kazimirkai]

6 minutes ago, stadiumwave said:

 

Mean never gets to normal at all now throughout the forecast period. 

lotta spread though 

[MJO812]

8 minutes ago, michsnowfreak said:

Weeklies below avg every week here. SE ridge definitely appears to have been overdone.

Its below average through the 1st week of January  even here also.

[TheClimateChanger]

 

[MJO812]

[Terpeast]

13 minutes ago, kazimirkai said:

lotta spread though 

True, but more and more members falling below the mean and even reversing. Still very far out and can/will change a ton, though. 

[leo2000]

23 minutes ago, kazimirkai said:

lotta spread though 

Confirms what I have been thinking (so far). We shall see though. 

[GaWx]

Regarding today’s Euro Weeklies, it’s the most bullish (i.e., colder changes vs prior run) overall in a long time in the NE and SE. I’m not saying they’re cold in the SE,  but they are colder than they were/not as mild or not mild overall. I don’t have time to post details right now, but y’all check it out! Or someone else please post the maps.

Edit: Every one of the 5 weeks is colder and/or less mild in both the NE and SE US vs yesterday’s run including one dramatically colder week. That hasn’t happened in quite awhile.

[stadiumwave]

1 hour ago, kazimirkai said:

lotta spread though 

 

Of course, there is always a large spread in LR. I said the mean. The mean had been going above normal for several days...it is not now. That is why I shared it.

There are a lot of members much, much weaker, even implying a possibility of maybe future warming. 

[leo2000]

 

 

 

 

 

Precip predictions

 

 

 

 

 

 

[donsutherland1]

The pattern evolution for the opening 10 days of December still looks very good. With respect to the December 11-25 period, the guidance has shifted. For a time, the GEFS was showing the development of a pronounced AO+ pattern. Now, it has backed off (12z and 18z cycles). As a consequence, the baseline Scenario 1 still seems to be the best one going forward, while recognizing that there is some risk of a break near mid-month. 

The latest ECMWF weekly forecast largely maintains the sensible weather effects from Scenario 1. Given the shifting of the guidance, it makes sense to continue to monitor the teleconnections (and other factors) while reserving judgment for changes until later to avoid making changes based more on model noise than actual developments.

Milwaukee, Chicago, Detroit, and Toronto remain in line for a snowstorm during the November 29-30 period. Significant snow is possible in Milwaukee and Chicago. A moderate snowfall looks reasonable for both Detroit and Toronto. Changes can still occur. WPC is now showing a 70% chance of a moderate winter storm impact in Chicago and surrounding areas for the 24-hour period ending November 30 7 am.

Chicago remains on course to experience its snowiest fall since 2019 (8.3") and possibly even 2018 (12.7"). Milwaukee should see its snowiest fall since 2019 (13.4"). Detroit will likely experience its snowiest fall since 2021 (7.1") and possibly 2019 (9.5"). Toronto could see its snowiest fall since 2020 (23.4 cm/9.2") and perhaps 2002 (27.2 cm/10.7").

Fall 2025 Snowfall Totals (through November 26):
Chicago: 1.7"
Detroit: 2.2"
Milwaukee: 0.6"
Toronto: 12.8 cm (5.0")

 

[so_whats_happening]

13 hours ago, 40/70 Benchmark said:

Where did you pull those graphics from?

https://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/Composites/Temperature/

[GaWx]

37 minutes ago, donsutherland1 said:

The pattern evolution for the opening 10 days of December still looks very good. With respect to the December 11-25 period, the guidance has shifted. For a time, the GEFS was showing the development of a pronounced AO+ pattern. Now, it has backed off (12z and 18z cycles). As a consequence, the baseline Scenario 1 still seems to be the best one going forward, while recognizing that there is some risk of a break near mid-month. 

The latest ECMWF weekly forecast largely maintains the sensible weather effects from Scenario 1. Given the shifting of the guidance, it makes sense to continue to monitor the teleconnections (and other factors) while reserving judgment for changes until later to avoid making changes based more on model noise than actual developments.

Milwaukee, Chicago, Detroit, and Toronto remain in line for a snowstorm during the November 29-30 period. Significant snow is possible in Milwaukee and Chicago. A moderate snowfall looks reasonable for both Detroit and Toronto. Changes can still occur. WPC is now showing a 70% chance of a moderate winter storm impact in Chicago and surrounding areas for the 24-hour period ending November 30 7 am.

Chicago remains on course to experience its snowiest fall since 2019 (8.3") and possibly even 2018 (12.7"). Milwaukee should see its snowiest fall since 2019 (13.4"). Detroit will likely experience its snowiest fall since 2021 (7.1") and possibly 2019 (9.5"). Toronto could see its snowiest fall since 2020 (23.4 cm/9.2") and perhaps 2002 (27.2 cm/10.7").

Fall 2025 Snowfall Totals (through November 26):
Chicago: 1.7"
Detroit: 2.2"
Milwaukee: 0.6"
Toronto: 12.8 cm (5.0")

 

 Look at how much colder H5 on the Euro Weeklies is compared to yesterday’s: that’s a big change for a 30 day period!

Yesterday’s:

Today’s:

[40/70 Benchmark]

December update....no changes.

https://easternmassweather.blogspot.com/2025/11/wintry-december-forecast-remains-on.html

[GaWx]

AAM has been verifying much more + than CFS ensemble forecasts have been indicating in the relative short term: if it can’t even get the relative short term right, how credible are these CFS ens. progs?

Today’s (11/27) run has +0.5 to +1.0 late Nov/1st part of Dec:

But look at what earlier runs had for the same period:

11/21 run: -0.25

 

11/19 run: -1

11/16 run: -1.5

11/11 run: -1 to -1.25

[snowman19]

@40/70 Benchmark As you and @Bluewave suspected…..
 

[bluewave]

31 minutes ago, snowman19 said:

@40/70 Benchmark As you and @Bluewave suspected…..
 

You can see how the long range models continue to underestimate the forcing near the Maritime Continent with the record warm pool there leading to the stronger Northern Stream of the Pacific Jet. So it interferes with the progression to a true MJO 8 500 mb and storm track pattern with the weaker Pacific Jet. This is why the RMM charts appear to show a slowdown or loop near the 7-8 border and lowering amplitude toward the circle following the higher amplitude 7.

New run

Old run

WPAC warm pool with expansive area of +28C to +30C SSTs

 

[SnoSki14]

Favorable snow pattern for midwest/lakes and C/N New England. Lean towards cooler than normal further south but likely too warm for snow due to unfavorable storm track. 

[GaWx]

Yesterday’s (11/26) GEFS 2 week through 12/10: was then curling back away from 8 and we were wondering whether it would ever make phase 8:

Yesterday’s (11/26) GEFS extended, which adds 12/11-12/27: it turned out that it made phase 8 for an 8 day period (12/13-20), which would be longest phase 8 since Feb of 2019’s 9 day long ph 8 and the longest Dec ph 8 since Dec of 1989’s 10 day long ph 8 along with it being a more favorable for cold weak to moderate amp:

[snowman19]

48 minutes ago, bluewave said:

You can see how the long range models continue to underestimate the forcing near the Maritime Continent with the record warm pool there leading to the stronger Northern Stream of the Pacific Jet. So it interferes with the progression to a true MJO 8 500 mb and storm track pattern with the weaker Pacific Jet. This is why the RMM charts appear to show a slowdown or loop near the 7-8 border and lowering amplitude toward the circle following the higher amplitude 7.

New run

Old run

WPAC warm pool with expansive area of +28C to +30C SSTs

 

There’s a standing wave there (near Maritime Continent). Not hard to figured out why either with +30C SSTs. Thermodynamics 101. The atmosphere will always put the strongest and most persistent convection over the warmest waters…..

[stadiumwave]

Amazing how quite 

1 hour ago, snowman19 said:

@40/70 Benchmark As you and @Bluewave suspected…..
 

 

You were amazingly quiet yesterday. 

[GaWx]

 Yesterday’s (11/26) EPS 2 week MJO forecast through Dec 10th: was then curling back away from 8 after barely getting into it and we were wondering whether it would ever get back to phase 8:

 

Yesterday’s (11/26) EPS extended, which adds 12/11-27: had a 15+ day phase 8 12/13-27, which would be the 2nd longest phase 8 on record for any month (2nd only to the 18 day long phase 8 of Dec-Jan 1975-6) and the more favorable for cold weak to moderate amp (vs strong) to boot:

[SnoSki14]

On the bright side today shows the MJO getting to phase 8, which reflects the early snow threats to our N/W zones 

[GaWx]

 Yesterday’s (11/26) 2 week GEFS (through 12/10): didn’t make it to phase 8 (extended showed it made it but not til 12/13):

Today’s (11/27) 2 week GEFS through 12/11: already makes it to phase 8 on 12/3, which is TEN days earlier than yesterday. It remains in phase 8 through the end, meaning it would be a 9+ day phase 8, the longest Dec phase 8 since 1989:

 

[Terpeast]

7 minutes ago, GaWx said:

 Yesterday’s (11/26) 2 week GEFS (through 12/10): didn’t make it to phase 8 (extended showed it made it on 12/13:

Today’s (11/27) 2 week GEFS through 12/11: makes it to phase 8 on 12/3, which is TEN days earlier than yesterday. It remains in phase 8 through the end, meaning it would be a 9+ day phase 8, the longest Dec phase 8 since 1989:

 

Yeah, according to hovmollers the models are trending towards weaker forcing at 6/7 after Dec 7. Between now and Dec 7, we have a clean mjo 8 pass. Then weak forcing reappears at 6/7, which is strongest with gefs. But even the gefs begins to propagate that eastward after Dec 7-10. So we may yet get another mjo 8 pass soon afterward.

MC ssts also have been cooling recently:

[GaWx]

24 minutes ago, Terpeast said:

Yeah, according to hovmollers the models are trending towards weaker forcing at 6/7 after Dec 7. Between now and Dec 7, we have a clean mjo 8 pass. Then weak forcing reappears at 6/7, which is strongest with gefs. But even the gefs begins to propagate that eastward after Dec 7-10. So we may yet get another mjo 8 pass soon afterward.

Yesterday’s (11/26) 2 week EPS (through 12/10): barely made it to phase 8 on Dec 5th-6th before circling back to phase 7 (extended showed it made it back to phase 8 12/13-27+):

Today’s (11/27) 2 week EPS through 12/11: gets to phase 8 on 12/3 and stays through the end of the run (12/11), meaning a 9+ day long phase 8, which would be the longest Dec phase 8 at least since the 10 day long phase 8 of 1989: (tomorrow’s ext EPS will show the total length)

 

In summary, all GEFS/EPS MJO forecasts are more favorable with regard to phase 8 vs what was available yesterday (2 week and extended). Both of today’s 2 week forecasts (GEFS and EPS) have phase 8 Dec 3-11+.

[EastonSN+]

Seeing the waters in the western Pacific continue to cool is a great sign. One MET who was likely joking said "for the rest of our lives" regarding the "boiling" westpac warm pool. 

Also seeing the potential for a clear pass through phase 8 in December is another good sign. 

All in all good trends. 

[snowman19]

7 minutes ago, EastonSN+ said:

Seeing the waters in the western Pacific continue to cool is a great sign. One MET who was likely joking said "for the rest of our lives" regarding the "boiling" westpac warm pool. 

Also seeing the potential for a clear pass through phase 8 in December is another good sign. 

All in all good trends. 

The waters are cooling there in the short term due to persistent strong convection in that area from the standing wave

[EastonSN+]

2 minutes ago, snowman19 said:

The waters are cooling there in the short term due to persistent strong convection in that area from the standing wave

Why wouldn't they continue to cool? Through history all sections of the pacific have had warming and cooling trends.