2025-2026 ENSO

[BlizzardWx]

It was 86 degrees at my place today. I hope we can get some payback later into January. EPS weeklies definitely looking more promising mid month. 

[GaWx]

51 minutes ago, BlizzardWx said:

It was 86 degrees at my place today. I hope we can get some payback later into January. EPS weeklies definitely looking more promising mid month. 

When you consider that both the EPS and GEFS have had a notable -PNA bias/notable warm bias from your area eastward and that all -ENSO -PNA Decs have transitioned to +PNA Jans, these consistently much better pattern maps for mid-Jan are quite encouraging. Just 5 days ago, the EW had this ugly -PNA for 1/12-18:

[stadiumwave]

0z Euro....lol

[bluewave]

22 hours ago, GaWx said:

-NYC now up to 7.2” snow this month, snowiest since Jan of ‘22. Thus, using stats @bluewaveand @donsutherland1got me informed about, I’m now forecasting a season total of 30” min., highest since at the very least 20-21.

-NYC headed to ~5 BN this month, coldest vs norm since Mar of ‘15!

 

[snowman19]

On 12/26/2025 at 7:55 PM, 40/70 Benchmark said:

There is my +PNA. Looks like the blocking reprieve won't last as long as I thought since the Strat and troposphere are remaining uncoupled, but I did get the strengthening PV right.

I’m still of the strong opinion that we are going to need your possible big stratospheric shakeup to avoid a canonical La Niña February. That’s the only reason/way I see that we would deviate from what has been a classic front-loaded Niña winter since the end of November 

[donsutherland1]

January looks to get off to a cool start in the eastern U.S. and Great Lakes Region. The Southwest will likely remain abnormally warm for at least the opening of January.

The latest EPS teleconnection forecast calls for the development of a predominant WPO+/EPO+/AO-/PNA+ pattern. It may take some time for the PNA+ to develop. That's probably where the greatest uncertainty lies. An alternative scenario involves a continuation of the WPO-/PNA- in combination with the EPO+/AO-.  If the PNA+ fails to develop and the WPO goes positive, warmth could develop on a larger scale across North America with the cold being limited to mainly Alaska and Canada. That is currently a low probability outcome but a wildcard that can't be dismissed.

EPS 9-13 Day Outlook:

WPO+/EPO+/AO-/PNA+ (January 1-10, 1980-2025):

ECMWF Weeklies (December 29-January 5):

ECMWF Weeklies (January 5-January 12):

The development of a predominant WPO+/EPO+/AO-/PNA+ pattern is the baseline scenario. Despite some social media rumors of a big snowstorm in parts of the East during the first 7-10 days of January, the forecast teleconnections typically do not favor large East Coast snowstorms. Instead, they favor lighter snows. For reference, New York City had no 6' or above snowstorms during January 1-10, 1950-2025 with a WPO+/EPO+/AO-/PNA+ pattern.

[SnowGoose69]

3 hours ago, snowman19 said:

I’m still of the strong opinion that we are going to need your possible big stratospheric shakeup to avoid a canonical La Niña February. That’s the only reason/way I see that we would deviate from what has been a classic front-loaded Niña winter since the end of November 

Probably the longer it takes the +PNA to develop the less February ends up mild because it tends to be a difficult pattern to flip out of rapidly, so if it does not establish til around 1/15 I could see it being 2/10 or 2/15 before we really begin to get that setup.  In recent really mild Februarys in the La Nina years January has tended to be cold from the very beginning.  I think outside of the Lakes/NE its going to be 1/12 or so til we see the cold anomalies get down into the SE/TN Valley/Plains

[MJO812]

[GaWx]

6 hours ago, bluewave said:

 

I looked at the NYC snowfall for the 17 -ENSO winters for which Dec was cold and had snowfall of 6”+ (from @donsutherland1updated list):

 

Year (Dec)..Total Season..Jan+

1872….60.2….29.9

1874….56.4….46.3

1886….31.9….21.6

1893….39.2….30.9

1903….32.4….26.0

1909….27.2….17.4

1915….50.7….42.6

1916….50.7….36.2

1917….34.5….20.1

1922….60.4….51.4

1926….22.3….10.6

1933….52.0….36.6

1942….29.5….21.0

1944….27.1….20.4

1995….75.6….61.2

2000….35.0….21.6

2010….61.9….41.8

————————

Analysis:

-AVG of these Jan+: 31.5” vs 22.1” full 156 year record mean or 143% of mean for Jan+ (median was 29.9”)

-41% (7 of 17) had 35”+ for Jan+ vs only 12% of the other 139 (17 of 139)

-These 17, which are only 11% of the total 156 on record, had:

1. Highest Jan of the 156 on record (2011’s 36.0”) and 3 of top 5 Jans (2011, 1996, 1923)

2. 3rd highest Feb of the 156 (1934’s 27.9”)

3. 2nd highest Mar of the 156 (2016’s 25.5”)

4. Highest Apr of the 156 (1875’s 13.5”) and tie for 5th (1917’s 6.5”)

—————————

My NYC total 2025-6 snow prediction based on these stats:

 40” (most likely range 30-50”)

 This compares to 156 year and 35 year means of 28”.

[michsnowfreak]

Weeklies continue to show cold in the Great Lakes the entire run. The widespread cold signal for Jan 19-26 is very stark for so far out.

[leo2000]

A lot colder euro weeklies today on the East Coast!

[leo2000]

1 minute ago, GaWx said:

 Check out how much weaker the SPV forecast is at 10 mb based on the 60N mean zonal wind on the Euro Weeklies!

 One week ago (12/21 run): quite strong just about all Jan through Feb 4th with no end in sight (mean 40-47 m/s):

 

Today (12/28 run): near normal Jan 10th-Feb 11th (mean only 25-35):

I am not surprised especially if the polar vortex splits one piece near eastern USA and Canada and the other to Europe. 

[GaWx]

On 12/24/2025 at 6:09 AM, snowman19 said:

FWIW, The stratospheric guru Judah Cohen thinks there’s going to be a major strengthening of the SPV in January
 

 Well, check this out:

 Look at how much weaker the SPV forecast is at 10 mb based on the 60N mean zonal wind on the Euro Weeklies!

 One week ago (12/21 run): quite strong just about all Jan through Feb 4th with no end in sight (mean 40-47 m/s):

 

Today (12/28 run): near normal Jan 10th-Feb 11th (mean only 25-35):

[Eskimo Joe]

14 hours ago, BlizzardWx said:

It was 86 degrees at my place today. I hope we can get some payback later into January. EPS weeklies definitely looking more promising mid month. 

Wow that's terrible. 

[Krs4Lfe]

15 minutes ago, michsnowfreak said:

Weeklies continue to show cold in the Great Lakes the entire run. The widespread cold signal for Jan 19-26 is very stark for so far out.

Sometimes guidance can correctly latch onto big cold blasts or warmups far in the distance. I remember how well the January 2019 cold blast and early February 2019 cold blast was forecast. Got down to near 0 here in NYC. Down near -30 in Chicago. Very impressive cold blasts that winter 

[MJO812]

[GaWx]

20 hours ago, jaxjagman said:

Has NINA actually not peaked,i mean the East is warning and the west gets cooler each day

Jax, The OHC has orange for the first time since early July:

[MJO812]

19 minutes ago, GaWx said:

 Well, check this out:

 Look at how much weaker the SPV forecast is at 10 mb based on the 60N mean zonal wind on the Euro Weeklies!

 One week ago (12/21 run): quite strong just about all Jan through Feb 4th with no end in sight (mean 40-47 m/s):

 

Today (12/28 run): near normal Jan 10th-Feb 11th (mean only 25-35):

Weeklies are loaded through February 12. Very nice pattern for the east.

[stadiumwave]

35 minutes ago, GaWx said:

 Well, check this out:

 Look at how much weaker the SPV forecast is at 10 mb based on the 60N mean zonal wind on the Euro Weeklies!

 One week ago (12/21 run): quite strong just about all Jan through Feb 4th with no end in sight (mean 40-47 m/s):

 

Today (12/28 run): near normal Jan 10th-Feb 11th (mean only 25-35):

Yes,started changing a couple of days ago rather rapidly. Been the same story since NOV

[MJO812]

1 minute ago, stadiumwave said:

Yes,started changing a couple of days ago rather rapidly. Been the same story since NOV

The first hit that the PV took was a huge blow. Its going to take a while for it to recover. We haven't seen that big of a hit in a long time. 

[jaxjagman]

33 minutes ago, GaWx said:

Jax, The OHC has orange for the first time since early July:

I know,i posted this in our severe thread earlier,its kinda like 2023

 

[jaxjagman]

5 minutes ago, jaxjagman said:

I know,i posted this in our severe thread earlier,its kinda like 2023

 

Its happened before with the AR out west during a NINA,buts its still more common with a NINO not NINA,it happened before in the winter of 2022-23

 

[michsnowfreak]

3 hours ago, Krs4Lfe said:

Sometimes guidance can correctly latch onto big cold blasts or warmups far in the distance. I remember how well the January 2019 cold blast and early February 2019 cold blast was forecast. Got down to near 0 here in NYC. Down near -30 in Chicago. Very impressive cold blasts that winter 

That's what im hoping. Just need to get snow back and then it can stay cold cold cold. We had snow on the ground from Nov 29 thru Dec 20. Now the ground has been bare a week and those high dews with tonight's storm will even nuke any remaining piles til the arctic front and snow squalls tmrw. 

[40/70 Benchmark]

14 minutes ago, 40/70 Benchmark said:

December recap and January preview...LOTS to dicsuss and more to come.

https://easternmassweather.blogspot.com/2025/12/december-colder-than-forecast.html

 

[BlizzardWx]

8 hours ago, Eskimo Joe said:

Wow that's terrible. 

It really was, a full 6 degrees above the old monthly record! 

[stadiumwave]

[PhiEaglesfan712]

14 hours ago, Krs4Lfe said:

Sometimes guidance can correctly latch onto big cold blasts or warmups far in the distance. I remember how well the January 2019 cold blast and early February 2019 cold blast was forecast. Got down to near 0 here in NYC. Down near -30 in Chicago. Very impressive cold blasts that winter 

That was the last real cold blast in the Eastern US. That was also the only winter in the last decade (since 2015-16) that didn't have a uber warm (+5.0 temperature departure) month in the November-March period.

If we don't get a torch month in January, February, or March, we would really be bucking a trend.

[snowman19]

2 hours ago, PhiEaglesfan712 said:

That was the last real cold blast in the Eastern US. That was also the only winter in the last decade (since 2015-16) that didn't have a uber warm (+5.0 temperature departure) month in the November-March period.

If we don't get a torch month in January, February, or March, we would really be bucking a trend.

My opinion…..Given the that this La Niña has been a classic, front-loaded event up to this point, I would not be surprised by a colder than normal January, we’ve been colder than normal since November. That said, I would definitely be shocked if Nov, Dec, Jan, Feb and Mar are all colder than normal. Color me very skeptical of all 5 months in a row being below normal for temps. We haven’t seen a La Niña do that since 1995-96 (which was a very anomalous, atypical Niña with a strong +PDO) and I just don’t see that happening

[40/70 Benchmark]

19 minutes ago, snowman19 said:

My opinion…..Given the that this La Niña has been a classic, front-loaded event up to this point, I would not be surprised by a colder than normal January, we’ve been colder than normal since November. That said, I would definitely be shocked if Nov, Dec, Jan, Feb and Mar are all colder than normal. Color me very skeptical of all 5 months in a row being below normal for temps. We haven’t seen a La Niña do that since 1995-96 (which was a very anomalous, atypical Niña with a strong +PDO) and I just don’t see that happening

Completely reasonable take.

[GaWx]

 The 0Z EPS (another run with a transition to a +PNA and a chilly E US) and the 0Z/6Z GEFS (staying -PNA and a warm E US) are in different worlds for mid Jan.

 The CPC GEFS forecasts of yesterday vs today show a bad 24 hour trend if you want it cold in the E US in mid-Jan:

Yesterday’s GEFS PNA forecast was heading up/nice trend vs earlier runs:

 

Today’s 0Z GEFS said never mind, I’ll stay -PNA through the end of the run: yuck

 

 GEFS 0Z 360 hour 2m temps: mild in E US with the cold way out to the NW….yuck

 

 But the good news is that the GEFS has had a persistent -PNA and warm E US bias over the 90 day period for this map:

 

And the EPS, a better performing and recently steadier ensemble, still has a +PNA and a chilly E US: