2025-2026 ENSO

[MJO812]

No backpedaling here

P8

 

[MJO812]

Further south dip

 

[MJO812]

Weeklies are great for December. They kill the SE ridge.

[GaWx]

39 minutes ago, MJO812 said:

Further south dip

 

This shows that the Euro is now leaning toward that later period for the actual reversal (~11/28 instead of 11/25). Add in a several week lag and a potential of a phase 8 MJO followed hopefully by 1-2 and we’d have a realistic chance for a several week long period of cold domination in the E US starting as early as near mid-Dec. Prior to this potential, there’d also likely be a mild dominated next 30 days, which shouldn’t be ignored.

[donsutherland1]

In conjunction with its annual Holiday train show, the New York Botanical Garden is running a feature called "the Nightmare Before Christmas Light Trail." Some of these characters could well have been taken from this thread.

The Southeast Ridge

Waiting for Winter

[mitchnick]

24 minutes ago, donsutherland1 said:

In conjunction with its annual Holiday train show, the New York Botanical Garden is running a feature called "the Nightmare Before Christmas Light Trail." Some of these characters could well have been taken from this thread.

The Southeast Ridge

Waiting for Winter

 

 

 

Been a Iong time since I've been to a great train show. I have a bunch of trains from my youth in my closet to this day in fact. Can't get myself to throw them out or otherwise part with them. Plus, a few are worth a couple of bucks...more evidence of one's age. 

[GaWx]

1. AAM is now dropping back from neutral and is forecasted to be in a solid -AAM (solid Ninaish) through the next 30 days per this CFS ens run:

 

2. WCS daily PDO has risen steeply the last 6 days and is up to -0.83, the highest daily since May:

[SnowGoose69]

One notable thing today is a -NAO, albeit a weak one showing up at the end of all ensemble runs.  It makes a difference for sure, even if its just -1 if its far enough west as far as flattening the SE ridge component 

[MJO812]

[leo2000]

35 minutes ago, MJO812 said:

The best you can ask for really its going to happen for sure now. 

[BlizzardWx]

These aren't very polished, but for fun here is the GFS, GEFS, and CMCE 10 hPa zonal mean wind for the next 16 days. CMCE is on board with the SSW in the mean, GEFS is lagging. 

[snowman19]

@Gawx Sunspots over 110 so far this month. Very high geomag continuing as well, as has been the case since solar activity picked back up in August. If this follows the trend you found since 1979, this is very likely to be a +NAO winter
 

 

 

 

 

[bluewave]

11 hours ago, SnowGoose69 said:

One notable thing today is a -NAO, albeit a weak one showing up at the end of all ensemble runs.  It makes a difference for sure, even if its just -1 if its far enough west as far as flattening the SE ridge component 

The only Southeast ridge component that really matters is on the day of the storms like last winter.

Even if a Southeast ridge isn’t showing in the means, if a storm is tracking through the Great Lakes we will get the Southeast ridge to flex for a day before the storm cuts to our west or hugs the I-78 to I-84 corridor.

Long range ensembles never show this since they are too smoothed out in the long range and have trouble seeing the individual shortwaves. We really haven’t seen a gradient pattern work closer to NYC in a long time due to this for more than light snows. 

[40/70 Benchmark]

On 11/14/2025 at 7:27 PM, Maestrobjwa said:

But that would be kinda atypical for a nina, no?

If they were all the same, Outlooks would be easy.

[40/70 Benchmark]

22 hours ago, GaWx said:

 I just looked up -ENSO winters with a -PNA in Dec to see how often it went to a +PNA in Jan. In what winters did this occur?

-1954-5: -0.52 to +0.40

-1962-3: -0.08 to +0.58

-1983-4: -0.31 to +0.97

-1984-5: -1.60 to +1.63

-1996-7: -1.23 to +0.63

-1998-9: -0.09 to +0.16

-2008-9: -1.41 to +0.61

-2010-11: -1.78 to +1.29

-2012-3: -1.01 to +0.55

-2013-4: -0.86 to +0.97

-2016-7: -0.35 to +0.28

-2021-2: -2.56 to +1.01

-2022-3: -0.66 to +0.22

 So, although it wasn’t common from 1954-5 through 1971-2, when only 2 of 9 (22%) switched, here’s something that just blew my mind:

-ALL 11 -ENSO -PNA Decs since 1983-4 switched to +PNA Jans (listed above)!

-These 11 averaged +0.76 in January!

-Now, check out the -ENSO Jan PNAs since 1983-4 that had a +PNA in Dec:

1) 1985-6 went from +1.39 to +0.97

2) 1988-9 went from +0.63 to -0.72

3) 1995-6 went from +0.92 to -0.02

4) 1999-00 went from +0.21 to -0.82

5) 2000-01 went from +1.23 to +1.51

6) 2001-2 went from +0.56 to -0.04

7) 2005-6 went from +1.38 to -0.43

8) 2007-8 went from +0.14 to -0.32

9) 2011-2 went from +0.36 to +0.60

10) 2017-8 went from +0.89 to +0.40

11) 2020-1 went from +1.58 to +0.19

12) 2024-5 went from +1.70 to +1.05

 -So, for these 12 -ENSO Decs since 1983-4 with a +PNA, only 50% also had a +PNA in Jan.

-So, since 1983-4, whereas only 50% of the 12 -ENSO Decs with a +PNA also had a Jan +PNA, 100% of the 11 -ENSO Decs with a -PNA in Dec went to a +PNA in Jan! Thus, having a -PNA in Dec during -ENSO since 1983-4 has, if anything, meant a big increase in the chance for a +PNA in Jan whether random or not! I didn’t know this til just now.

Link to monthly PNAs back to 1950:

https://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/norm.pna.monthly.b5001.current.ascii.table
 

@donsutherland1

Yes, I do expect a +PNA month of January.

[donsutherland1]

ENSO Region 1+2 has see a recent, fairly sharp cooling.

This decline is in line with the ECMWF Seasonal Forecast from November 1. As a result, the development provides a measure of confidence that its forecast is on track at this point.

[stadiumwave]

15 day change

[stadiumwave]

Good ol Nina

[GaWx]

11/17/25 MJO forecasts is mixed bag:

1) 11/17/25 GEFS backtracked to ~2 days slower than yesterday’s slightly more progressive/weaker run to being nearly identical to the more lethargic and stronger run of 11/15 (not what I wanted to see):

GEFS 11/17: stronger/less progressive vs GEFS 11/16 and close to GEFS 11/15

 

GEFS 11/16: was slightly more progressive/weaker than GEFS 11/15

 

GEFS 11/15:

 

—————

2) However, 11/17/25 EPS remains similar to yesterday’s slightly more progressive run and continues to be a good bit more progressive/weaker than GEFS, two things I like:

11/17 EPS: similar to 11/16 EPS and more progressive/weaker than 11/17 GEFS

 

11/16 EPS: slightly more progressive than 11/15 EPS

 

11/15 EPS:

[brooklynwx99]

3 hours ago, BlizzardWx said:

These aren't very polished, but for fun here is the GFS, GEFS, and CMCE 10 hPa zonal mean wind for the next 16 days. CMCE is on board with the SSW in the mean, GEFS is lagging. 

I’m pretty sure the GEFS has a strong/cold bias with the SPV, but i could be wrong

[snowman19]

1 hour ago, bluewave said:

The only Southeast ridge component that really matters is on the day of the storms like last winter.

Even if a Southeast ridge isn’t showing in the means, if a storm is tracking through the Great Lakes we will get the Southeast ridge to flex for a day before the storm cuts to our west or hugs the I-78 to I-84 corridor.

Long range ensembles never show this since they are too smoothed out in the long range and have trouble seeing the individual shortwaves. We really haven’t seen a gradient pattern work closer to NYC in a long time due to this for more than light snows. 

IF (If) the GEFS, EPS and GEPS are correct in how far west the ridge is going to set up (Bering Sea/Aleutians) in the long range, then yep,  they are underestimating the SE ridge

[snowman19]

10 minutes ago, GaWx said:

11/17/25 MJO forecasts is mixed bag:

1) 11/17/25 GEFS backtracked to ~2 days slower than yesterday’s slightly more progressive/weaker run to being nearly identical to the more lethargic and stronger run of 11/15 (not what I wanted to see):

GEFS 11/17: stronger/less progressive vs GEFS 11/16 and close to GEFS 11/15

 

GEFS 11/16: was slightly more progressive/weaker than GEFS 11/15

 

GEFS 11/15:

 

—————

2) However, 11/17/25 EPS remains similar to yesterday’s slightly more progressive run and continues to be a good bit more progressive/weaker than GEFS, two things I like:

11/17 EPS: similar to 11/16 EPS and more progressive/weaker than 11/17 GEFS

 

11/16 EPS: slightly more progressive than 11/15 EPS

 

11/15 EPS:

DT warned yesterday that the MJO push into phase 8 is looking like it’s going to be delayed… 

[bluewave]

On 11/14/2025 at 10:14 AM, GaWx said:

The longest drought during 1974-2009 was a mere 4 Decs. But during 2010-24, there have been two 7 Dec droughts!@bluewave

The main issue in recent years with MJO forecasts in general has been the record warm SSTs over the tropical WPAC to around the Maritime Continent stalling convection there.

So even if the RMM charts show the MJO going into phase 8, the VP charts will often have convection lingering over the WPAC.

Our last clean MJO 8 was back in January 2022. Recent  MJO 8 passages on the RMM charts didn’t match the classic MJO VP composites. Since the RMM charts did show a phase 8 but convection lingered near the Maritime Continent.

Plus another issue has been the convective forcing stalling in 6-7 before going into the circle or only a very low amplitude MJO 8.

So it’s better to monitor the velocity potential charts along with the RMM charts to get a complete picture of the convective forcing.

[40/70 Benchmark]

28 minutes ago, snowman19 said:

DT warned yesterday that the MJO push into phase 8 is looking like it’s going to be delayed… 

No one on the east coast below the latitude of NH should have been expecting any snow prior to the second week of December IMHO.

[MJO812]

Whats wrong with this ?

Nice ridge out west

50 50 low

good cold source

[chris21]

11 minutes ago, 40/70 Benchmark said:

No one on the east coast below the latitude of NH should have been expecting any snow prior to the second week of December IMHO.

I can just about guarantee accumulating snow at my house prior to the second week of December in North Carolina. Already have 7 inches on the board!

I average about the same as Portland, Maine though every year.

[MJO812]

14 minutes ago, 40/70 Benchmark said:

No one on the east coast below the latitude of NH should have been expecting any snow prior to the second week of December IMHO.

Never say never but holiday snow is great. 

[GaWx]

56 minutes ago, MJO812 said:

Whats wrong with this ?

Nice ridge out west

50 50 low

good cold source

Hey Anthony,

 What’s wrong from my perspective? prevailing SE ridge/-PNA.

 The MJO is then forecasted by GEFS to be strong near phase 6/7 border, which is typically mild in the E US. Strong phase 7s in Dec have often been mild in the E US. A big key will be whether or not it eventually makes it to phase 8 like the extended EPS has been showing. There’s been only ONE 3+ day Dec MJO phase 8 period the last 15 Decembers!

[40/70 Benchmark]

45 minutes ago, chris21 said:

I can just about guarantee accumulating snow at my house prior to the second week of December in North Carolina. Already have 7 inches on the board!

I average about the same as Portland, Maine though every year.

You are at almost 4,000', and not on the east coast. I mean literally on the east coast.

[MJO812]

10 minutes ago, GaWx said:

Hey Anthony,

 What’s wrong from my perspective? prevailing SE ridge/-PNA.

 The MJO is then forecasted by GEFS to be strong near phase 6/7 border, which is typically mild in the E US. Strong phase 7s in Dec have often been mild in the E US. A big key will be whether or not it eventually makes it to phase 8 like the extended EPS has been showing. There’s been only ONE 3+ day Dec MJO period the last 15 Decembers!

Weak phase 7 in a negative enso Decembers in EQBO years analogs are below normal in the northeast.

You have a - EPO in early December so the source region is cold. A negative PNA will create overrunning events N of the Mason Dixon line.

 

We shall see