2026-2027 Record-breaking El Nino

[jconsor]

23 hours ago, GaWx said:

 The chart below has 10 mb/60N winds back to 1949. According to it, Nov 2026 is going to per ERA obliterate the old record (all of the way back to at least 1949) earliest SSWe whether it gets down to 0 (major SSW) or stays just above. The earliest SSW on record is 1952’s ~Nov 15th SSW. So, 2026 is headed to possibly beat 1952 by ~11 days!

————————

 Looking at the above chart for only El Niño Novs, the only three that got to +5 or lower per ERA5 in Nov were 1968 (-5 on Nov 27th), 1976 (+4 on ~Nov 15th), and 2009 (+5 on ~Nov 15th). These three had the lowest DJF AO of any winters since at least 1949-50. Thus, these very strong winter -AOs were quite possibly connected to a large extent to the very weak Nov SPV period. Thus, a case could be made for a better than average chance for a strong -AO averaged out in 2026-7 despite the lack of seasonal model support:

1968-9: AO -2.3

1976-7: AO -2.6

2009-10: AO -3.4

@Typhoon Tip
 

*Edited for typo 

Very nice find, Larry!

While the seasonal model support for a strong -AO is mostly lacking, the sub-seasonal support is growing.  There is increasing support for a -AO in the last two-thirds of Nov.  EPS and GEFS long range weather regime charts show an increasing proportion with Greenland High (GH) or Alaskan ridge (AR) vs. prior forecasts. 

This is also reflected in individual member AO forecast charts from the long range EPS and GEFS.

Taking El Ninos of any strength, the four with a Nov AO below -1.0 saw that -AO persist overall through the winter and most of these were memorable winters with at least one KU event:

1957-58: -0.9
1965-66: -1.5
1968-69: -2.3
2002-03: -0.6
 

[snowman19]

I agree here that this is different than much of the last decade plagued by split forcing. I don't know that in the end it will mean any more snow or cold...but it is different and we shouldn't assume the last 12 years will necessarily hold this year. 

In the last 50+ years, the super El Niño that most closely resembles this one in development/evolution, forcing and orientation (even though this one is much stronger and more east-based) is 1997, hands down

[forkyfork]

remember in april when you hive members were trying to will this event under +2 because you knew it would be really bad for cold and snow this winter? now it's +3 and you're willing some kind of magic block that will defeat the pacific vortex

[GaWx]

It’s not +3. It’s ~+2.6 per NOAA. Record for any week is +2.9:

https://www.cpc.ncep.noaa.gov/data/indices/rel_wksst9120.txt

 Meanwhile there’s this to look at that shows strong +AAM still S of 30N:

 

@40/70 Benchmark

[forkyfork]

yes. i was wrong about the anomaly. it's actually +3.5

[MJO812]

So the pattern will not get colder even if its brief ? ^

[mitchnick]

Lower mean today....underwater 

[MJO812]

6 minutes ago, mitchnick said:

Lower mean today....underwater 

Its also weaker as time goes on .

[GaWx]

Check this colder change from the EWs for week 2 (Nov 9-15):

1. H5 2 runs ago:

Yesterday’s:

Today’s: nice E US trough

 

2m from 2 days ago:

Yesterday: cooler

Today’s: even cooler

 

Rainfall:

2 days ago: slightly wet SE

 

Yesterday’s: a little drier

 

Today’s: even drier with the colder air

[40/70 Benchmark]

20 hours ago, LibertyBell said:

I think we're in a cyclic dry pattern now. 65-66 72-73 and even a non nino like 01-02 would be my analogs 

65-72 was -AMO, I believe.....we were in a dry pattern in the NE bc we had MC forcing for the better part of a decade. ..I would not go dry this year.

[40/70 Benchmark]

1 hour ago, forkyfork said:

remember in april when you hive members were trying to will this event under +2 because you knew it would be really bad for cold and snow this winter? now it's +3 and you're willing some kind of magic block that will defeat the pacific vortex

I told you why I doubted the magnitude...had nothing to do with a desire for cold.

[40/70 Benchmark]

19 hours ago, OSUmetstud said:

The overshooting in forecasts is because the SST anomalies are farther east, not because the Nino is weaker. Both BOM and ECMWF SST anomaly forecast has been excellent and if anything undershooting the SSTs in Nino 3. 

I understand that, but it's still off...doesn't matter why.

[40/70 Benchmark]

18 hours ago, OSUmetstud said:

This is not how the real word works though. The anomalous trades are causing the most east-based event on record. Pointing out that these models just have the peak SST anomalies 10, 20, or 30 degrees east of the Nino 3.4 is relevant and different than the whole event being weaker. 

Getting Modoki value correct is part of what comprises an accurate ENSO forecast....you want to say EURO has been best, okay....but it's not been perfect is all I mean. 

[EasternLI]

12Z runs similar to 00Z. 98% EPS. 70% GEFS. Interesting little trend though lately on both Op runs with longer lasting reversals. 

 

 

[40/70 Benchmark]

10 hours ago, bluewave said:

My guess is that all these stratospheric disruptions in recent years are linked to the Kara-Barents Seas warming and loss of sea ice there. Many recent studies how focused on this region.

Notice how in most of the recent summers the Pacific side has done better than the Atlantic side. While the Pacific side enjoyed the coldest start to summer in a while this year, there was record breaking warmth with low sea ice on Barents and Kara areas.

So we have had quite a run of SSWs and weakened vortices since 2020. The successful SSWs and weaker PV for winter weather fans were in January 2021 and November 2025.

These events were able to get the Pacific to back off. Even though it took nearly three months following the November 2025 weak PV in late February for our first KU in four years to finally click.

Fast forward to the disruption of the PV in February 2023 and we saw the disappointing result of what such an overpowering Pacific leading to the Baja trough that winter could do. 

Next up were the twin SSWs in January 2024 and March 2024 during our last weaker super El Niño. But we saw quick snap backs of the PV following those events with the very hostile Pacific continuing. 

Now this early PV disruption is forecast to have a quick rebound. So it’s quite possible that we see another weakening sometime from January to March.

But with such an extreme east based El Niño, it’s an open question how much success it will result in. Since it could very well follow the 2024 quick rebound script. 

https://www.climate.gov/news-features/understanding-climate/understanding-arctic-polar-vortex

How Barents Sea Ice Affects the Stratosphere

• Heat and Moisture Flux: When sea ice retreats in the Barents-Kara Seas, open water exposes the relatively warm ocean to the atmosphere in autumn and early winter. This releases extra heat and moisture. [1]

• Planetary Wave Enhancement: The added heat creates local thermal anomalies that alter lower-atmosphere pressure patterns. This change enhances upward-propagating planetary waves (Rossby waves) from the troposphere into the stratosphere. [1, 2]

• Vortex Disruption: When these energetic waves break in the stratosphere, they deposit momentum and heat, weakening or distorting the high-altitude circumpolar winds known as the stratospheric polar vortex. In extreme cases, this triggers an SSW, where stratospheric temperatures jump tens of degrees in just a few days. [1, 2, 3]

https://repository.library.noaa.gov/view/noaa/67133

Major sudden stratospheric warmings (SSWs) occur in the Arctic around six times per decade. During winter 2023/2024, two major SSWs occurred – a relatively rare event, having occurred on average only once per decade. Here, we summarise the evolution of the two SSWs, their dynamics and impacts on stratospheric chemical processing and tropospheric weather patterns. While both SSWs were displacement events, they evolved remarkably differently. The 16 January SSW was short‐lived and did not exert a canonical influence on surface weather. In contrast, the 4 March SSW followed a more typical evolution, albeit with only weak coupling to the troposphere.

2023-2024 had strong MC forcing though, which as you know is significant source of destructive interference for high latitude blocking. I don't deny that this is probably CC enhanced, and perhaps it won't end up meaning much...I'm open to that, but I don't think that we can summarily dismiss it as an artifact of CC.

[40/70 Benchmark]

7 hours ago, LakePaste25 said:

Here we go. Massive extratropical WWB in the NH due to the N Pac cyclone. This will help flip the -PDO, and it’s why I say it’s a lagging indicator of ENSO, because the tropical coupling comes first, then the NHem coupling followed by the PDO. 

 

Of course it lags, but it leads you to the driver.

[40/70 Benchmark]

5 hours ago, snowman19 said:

IMO I see no reason to deviate from my +QBO/El Nino December guess. I completely agree with @Winter Wizard take:

“Down the line, that seems like a discouraging sign for December. After initial weakening, the PV rapidly rebuilds and that is another piece of evidence pointing toward a very warm December. which is a strong signal in historic analogs. Recall that last year, the disruption occurred in late November and that contributed to a cold start in December with an Arctic spell mid-month. The end of December into early January torched for the majority of the CONUS right as the PV rebuilt.

I suspect this time, if it even couples to the troposphere, it would only really benefit Europe with cold/snow based on the large scale pattern.

Maybe it implies potential for disruptions or splitting later in the season, but historically that is less likely with this ENSO/QBO combo. Either way, I think there are bad actors who are clinging onto this as confirmation bias of cold/snow in order to sell subscriptions or get social media views.”

 

 

 

 

Probably right, but you also have to leave open for the possibility that the longer range defaults towards climo.

[Terpeast]

6 hours ago, frontranger8 said:

The great thing about analogs is that even the most "perfect" match does not mean the winter will be even close to it.

Yes. I would personally love to run the 25-26 analog back again, even if two KUs had missed my area. Flip side, running 09-10 again might not produce a record snowfall.

[EasternLI]

So, if you can have a weakened vortex. That part is important. Plus this residual -AAM in the mid latitudes. With something like a +MT to shove it towards the pole. You'd stand a pretty good chance to see some high latitude blocking actually.