2025-2026 ENSO

[LakePaste25]

2 hours ago, snowman19 said:

I have to agree with Eric Webb here. Despite what twitter is saying, this year looks absolutely nothing at all like last year at this time. It’s not even remotely close. The twitterologists either don’t have any semblance of a clue as to what they’re talking about or are straight up wishcasting if they think we are going right into the exact same pattern we had last winter by early January
 

It’s important to note however that Eric Webb was calling for a similar pattern as last year back in November (+TNH). His main caveat is that -PNA episodes would be more frequent this year. So far that is the case, and if @40/70 Benchmark is right, we could improve things by mid Jan. 

The phase 8 hype was clearly over the top and the MJO entering phase 8 (and then collapsing into repeated fast-moving KW’s) is what is about to give us this pattern. You’d almost want to see the MJO re-emerging over the MC in phases 4-6 to enhance the standing convection over the Indo-pacific warm pool, which would inject some more momentum into the pacific jet and help nudge things eastward. 

[PhiEaglesfan712]

1 hour ago, 40/70 Benchmark said:

March 2001 is another great analog.....maybe March 2023 with a less hostile Pacific.

Oh please, no March 2001. I would not wish that on any snow lover.

I'd prefer March 2017 as an analog.

[Krs4Lfe]

The pattern regression is quite impressive. There's no more being on the fence about that, the warm air will be pushing through this region and will likely result in the last 10 days of december being a few degrees above normal. Despite the -NAO, there's no opportunity for snow because no snow storms can form due to the coast to coast torch across CONUS. This is one of the quickest pattern regressions I've ever seen. All the calls for renewed cold air after this "brief" warmup will likely be very inaccurate. It'll take some pacific jet extension to shake this up, or there's a January 2020 and January 2023 repeat coming right up

[BlizzardWx]

The warmth continues to look impressive here, with mid 70s to low 80s for several days before and after Christmas. Likely a few record highs and max mins. The overall pattern continues to look messy to me and out of phase, perhaps from multiple competing factors. That tends to make it hard to secure anything really great in terms of winter weather down south. So for now I see nothing positive, but obviously that could change in a few weeks. 

[anthonymm]

On 12/18/2025 at 9:32 AM, donsutherland1 said:

For reference, the December and January snowfalls for New York City (1980-Present) with the teleconnections you listed:

PNA = king for the coastal plain. we simply do not get decent snows without it, with extremely rare exceptions.

[GaWx]

 The 12Z GFS has 6 days of the rest of Dec having a high of 70+ at KATL (12/24-29): 70, 73, 72, 70, 71, and 73. Granted, 2 of the 6 days on this barely make 70. So, getting 6 won’t be easy. Many models including earlier GFS runs don’t have 70+ on 12/29 with the 5 of 12/24-28 more common for the most.

 That being said, IF it were to actually occur, 6 days of 70+ at KATL within 12/20+ would obviously be a very impressive anomaly! How rare would that actually be? Extremely! It’s only occurred three times since 1878:

-2021 (warmest 75)
-2015 (warmest 77)
-1984 (warmest 74)

 Needless to say, this will be very interesting to follow!

[GaWx]

 Today’s Euro Weeklies are similar to the prior ones through Jan 11th with mild for much of the country though the warmest is closer to the C US, well away from the E US.

 However, today’s weeks 4-5 continue yesterday’s cooling trend:

1/12-18

12/17 run:

12/19 run:

 

1/19-25

12/18 run:

12/19 run:

 

And then week 6 is similar to yesterday’s in the E US:

 In summary, whereas the first 3 weeks (through 1/11) remain mild in much of the E US, the last 3 weeks (1/12-2/1) are mainly NN to a little BN in most of the E US with nothing even resembling warmth.

 The 1/19-25 map suggests a +PNA is trying to form:

[donsutherland1]

1 hour ago, anthonymm said:

PNA = king for the coastal plain. we simply do not get decent snows without it, with extremely rare exceptions.

For December through the first half of February, that's definitely the case. Big PNA- snowstorms are a rarity. However, once one gets to the second half of February, the PNA- is better (wave lengths are shortening).

[GaWx]

 I’ll add that today’s weeklies have a stronger -NAO/-AO forming for 1/12-2/1:

1/12-18:

 

1/26-2/1:

[Terpeast]

6 minutes ago, GaWx said:

 I’ll add that today’s weeklies have a stronger -NAO/-AO forming for 1/12-2/1:

1/12-18:

 

1/26-2/1:

If we’re going to maintain a -WPO, we’ll need the -NAO/-WPO ridge bridge to connect to push the TPV south into Canada making it easier to get a trough in the east. 

[michsnowfreak]

First time all of December we saw bare ground today (though we got a fresh dusting), neighbors snowman appears to be on ozempic. Im liking the look of both euro and cfs weeklies for January. Only christmas week appears hostile, and wouldn't you know it, the core of the warmth here will be Dec 25-26. The insane temp departures to the south won't make it to the north for long, but it certainly looks like a mild holiday week.

[MJO812]

2 hours ago, GaWx said:

 I’ll add that today’s weeklies have a stronger -NAO/-AO forming for 1/12-2/1:

1/12-18:

 

1/26-2/1:

Weeklies corrected big time. It finally pops a positive PNA. 

[PhiEaglesfan712]

[bluewave]

20 hours ago, 40/70 Benchmark said:

I'm sure everyone remembers how brutally awful I handled the El Nino a couple of years ago....was completely undressed by @bluewaveon how it would interact with the west Pacific. It was the best thing that ever happened to me in terms of my ability to forecast on a seasonal level

Don’t be so hard on yourself as you are one of the best forecasters on here.

When I saw how extreme the December2015  forcing for an El Niño  in the WPAC was leading to the +13.3 in NYC, it caused me to gain a ton of respect for what has been occurring in the WPAC. 
 

https://phys.org/news/2021-04-distinctive-mjo-super-el-nino.html

A research group, led by Dr. Wenjun Zhang from the Nanjing University of Information Science and Technology analyzed MJO activity of the super El Niño event during the Northern Hemisphere winter of 2015/16. Observations show that the western Pacific MJO activity was strongly suppressed during the peak phase of the 1982/83 and 1997/98 super El Niño events. However, during the crest of the 2015/16 super El Niño event, western Pacific MJO-related convection was enhanced.

"It is apparent that the enhanced western Pacific MJO is mainly related to its sea surface temperature (SST) anomaly distribution and the associated background thermodynamic conditions." said Dr. Zhang. His team's complete research and data are published in Advances in Atmospheric Sciences.

When compared to the previous super El Niño events, the warm SST anomaly, or change from average, of the 2015/16 El Niño was located more westward than during the other two extreme seasons. Additionally, no significant cold SST anomaly was detected in the western Pacific. Accordingly, the moisture and air temperature tended to increase in the central-western Pacific during the winter of 2015/16 unlike the previous super El Niño events.

This research highlights that climatologists should consider the SST anomaly distribution of super El Niño events for future MJO activity studies.

 

 

[GaWx]

The GEFS and EPS have big disagreement 12/25-1/3! Fwiw, JMA, BOM, and CFS favor GEFS:

 

Meanwhile, phase 8 , which helped bring strong cold Dec 3-7 and Dec 15 but won’t next week, returned on 12/17 and will likely be with us for awhile:

[Krs4Lfe]

The warmth over Central US is very impressive, akin to the very warm Christmas we had here in December 2014 and December 2015. This is one of the few times where you would want a pacific jet extension to force storms into the west, which will roll the ridge through the east US and then maybe we can reset from there. But until that omega ridge subsides over Central US, CONUS is almost completely void of cold and snow. Horrendous

[GaWx]

23 minutes ago, Krs4Lfe said:

The warmth over Central US is very impressive, akin to the very warm Christmas we had here in December 2014 and December 2015. This is one of the few times where you would want a pacific jet extension to force storms into the west, which will roll the ridge through the east US and then maybe we can reset from there. But until that omega ridge subsides over Central US, CONUS is almost completely void of cold and snow. Horrendous

Nationally, 12/25/25 is going to be close to the historically warm 12/25/21.

[PhiEaglesfan712]

13 minutes ago, GaWx said:

Nationally, 12/25/25 is going to be close to the historically warm 12/25/21.

I was in North Carolina Christmas weekend in 2021, and it was really warm. I even barbecued the 26th, and have the pictures to prove it: 

[Stormchaserchuck1]

Today's Euro weeklies are a disaster, have the same pattern going to Feb 2.

https://charts.ecmwf.int/products/extended-anomaly-2t?base_time=202512200000&projection=opencharts_north_america&valid_time=202602020000

Good news is they've been fluctuating a lot. 

Now strengthening 10mb PV modeled after the New Year:

[Terpeast]

25 minutes ago, Stormchaserchuck1 said:

Today's Euro weeklies are a disaster, have the same pattern going to Feb 2.

https://charts.ecmwf.int/products/extended-anomaly-2t?base_time=202512200000&projection=opencharts_north_america&valid_time=202602020000

Good news is they've been fluctuating a lot. 

Now strengthening 10mb PV modeled after the New Year:

Looks a lot different than yesterday. If they are fluctuating this much, it really lowers confidence in the weeklies at this time. 

[snowman19]

Today's Euro weeklies are a disaster, have the same pattern going to Feb 2.
https://charts.ecmwf.int/products/extended-anomaly-2t?base_time=202512200000&projection=opencharts_north_america&valid_time=202602020000
Good news is they've been fluctuating a lot. 
Now strengthening 10mb PV modeled after the New Year:

Yep. Judah Cohen warned yesterday that the SPV was going to strengthen

[George001]

On 12/19/2025 at 11:41 AM, Krs4Lfe said:

The pattern regression is quite impressive. There's no more being on the fence about that, the warm air will be pushing through this region and will likely result in the last 10 days of december being a few degrees above normal. Despite the -NAO, there's no opportunity for snow because no snow storms can form due to the coast to coast torch across CONUS. This is one of the quickest pattern regressions I've ever seen. All the calls for renewed cold air after this "brief" warmup will likely be very inaccurate. It'll take some pacific jet extension to shake this up, or there's a January 2020 and January 2023 repeat coming right up

It’s too early to say whether January will be cold and snowy or not. What we do know is the polar vortex is now to expected to strengthen well above average levels, which favors +NAO conditions. That’s a reasonable baseline to operate from when assessing the expected January pattern. But it remains unclear if we will go country wide torch (mild and rainy east) or +TNH (cold, snowy east). Based on historical precedence of -PNA La Niña Decembers transitioning to +PNA (or less -PNA) Januarys, I am in the +TNH camp. As always, it is important to be open to adapting as we get new information. Historical precedence > long range guidance, but if the warm signal strengthens for Jan and we are near new years, then it’s time to reevaluate.

[EasternLI]

There's a shakeup for the Pacific in the pipeline as we start getting into January. I think this could offer an opportunity for a period of +PNA after the 1st week when these waves break but we'll see. Maybe this ties into Ray's @40/70 Benchmark ideas mid-month so maybe it's part of that timing to transition to +TNH. But I think sometime week 2 we see some changes and maybe clues to that happening during the 1st week of the month.

 

We're being plagued with a series of -EAMT retracting the Pac jet and locking the Pacific block in place on guidance in perpetuity. High pressure into the west of the Himalayas removes the momentum. While high pressure on the east side would add it.

 

 

This is likely going to change as we start heading into January. An active convective phase looks to cross an Indian Ocean to MC transit to close out December. These set in motion a series of events that eventually leads to +EAMT and a Pacific jet extension.

Even at the end of the current EPS 12z I think we can see some signs of a changing Pacific regime. With high pressure building in Siberia in better position and a Jet beginning to be reinvigorated off the coast of Asia. 

[raindancewx]

December is more or less going how I expected, although more extreme. It never really looked like some consistently super cold pattern. To me it always looked like a pretty cold start and then a much warmer push back. Most of the country may actually finish warm. Locally we've literally never seen temps over 65F from mid-Dec to mid-Jan, so this level of warmth is pretty historic here and definitely more than I expected.

The Northwest is actually warmest relative to averages, which is not really consistent with -WPO, -PNA historically. It's just an ugly, unstable and volatile pattern.

Record cold all month...oops

My big theory theory is very simple: eventually La Nina Climatology kicks in. If you retain the cold in Canada, but add in the ridge over the Southeast in Jan and/or Feb and/or Mar, the cold will dump into the West eventually. Alaska and Western Canada are usually a good source region for us, especially if the La Nina / -PDO are to collapse late toward an El Nino or +PDO. I wouldn't be surprised if it happens a bit later than I initially expected though given how everything has gone to date.