November 2026

[Stormlover74]

A possible turn to wetter next week?

[NEG NAO]

The surface-level weather effects from a Sudden Stratospheric Warming (SSW) event in the United States typically last for 2 to 6 weeks on average. [1]

While a major SSW event drastically disrupts the polar vortex high up in the stratosphere, its effects do not impact ground weather immediately. Instead, there is a 10- to 20-day time lag as the atmospheric changes ripple downward to the surface, causing the jet stream to become wavy and unstable. [1, 2, 3]

Once those effects arrive, the impacts on U.S. weather patterns include:

• Prolonged Cold Spells: Rather than a brief cold snap, the weak polar vortex patterns lock in atmospheric blocks that can extend below-average temperatures for several weeks. [1, 2]
• Increased Storminess: A wavy jet stream frequently shifts the storm track, increasing the likelihood of extreme precipitation and winter storms. [1, 2]
• Regional Variation: An SSW event does not guarantee uniform cold across the entire country. For instance, a collapsed or split polar vortex often unleashes severe cold into regions like the Northern Plains or the Midwest, while other regions like the Eastern Seaboard can occasionally experience temporary warming depending on exactly where the cold air mass migrates.

Also 2009 -2010 featured a moderate to Strong El Nino BUT not as strong as this one. Along with that there was an SSW event in mid to late November and we ended up with 12 Inches of snow in December in NYC and January we had a break and ended up with 2 inches BUT we all remember what happened in February 2010 -36 Inches of snow in NYC. So 2009-  2010 is now an analog year.

•  
   
  [1, 2, 3]

 

 

The previous expectations of a back loaded winter by many might turn into a front and back loaded winter with a break in the middle in January - time will tell

[MJO812]

Teleconnections looking good for a cold snap. That would come mid November.

[Brian5671]

Early Nov looked cold instead we are getting big warmth.   might be a case of the the cold and snow is always 10 days away?

[MJO812]

13 minutes ago, Brian5671 said:

Early Nov looked cold instead we are getting big warmth.   might be a case of the the cold and snow is always 10 days away?

No it didnt. There is a lag and also warmth before these warming events. 

[Stormlover74]

Gfs mostly dry now next week

Cmc is widespread 2.5"+ though

[MANDA]

32 minutes ago, Stormlover74 said:

Gfs mostly dry now next week

Cmc is widespread 2.5"+ though

Just saw that.

Gotta watch the trends on the EURO/AI/EPS more than anything.  GFS lowest skill scores of almost any model and just read a piece from NOAA that the October 2026 upgrade from V16 to V17 has been pushed off a year to next October.  I hardly use the GFS for anything anymore.  I just find it useless, IMO.  We'll see how this evolves over the next 5 days or so.  Interesting to say the least.  Fact that CMC still has wet solution makes me lean in that direction at the moment....pending 12Z EURO/AI/EPS data.

Anything is better than the snooze fest that is ongoing now.

[Brian5671]

2 hours ago, MJO812 said:

No it didnt. There is a lag and also warmth before these warming events. 

I'd bet against cold with this PAC Jet roaring in.

[SnoSki14]

3 hours ago, Stormlover74 said:

Gfs mostly dry now next week

Cmc is widespread 2.5"+ though

Gfs is complete garbage now. I only look at Euro/Euro AI

[NEG NAO]

15 minutes ago, SnoSki14 said:

Gfs is complete garbage now. I only look at Euro/Euro AI

aren't the new models replacing some of the older models in November ?

[uofmiami]

1 hour ago, NEG NAO said:

aren't the new models replacing some of the older models in November ?

RRFS/REFS Go-Live & Legacy Model Retirements Nov 3

This is a reminder regarding major operational dataset changes taking effect on NOMADS (https://nomads.ncep.noaa.gov/) on Tuesday, November 3, 2026.

Key Changes & Path Updates:
1. Legacy Model Retirements (SCN 26-47):
  Data directories for the following retired models will no longer be updated and will be decommissioned:
  - NAM (/pub/data/nccf/com/nam/)
  - SREF (/pub/data/nccf/com/sref/)
  - HREF (/pub/data/nccf/com/href/)
  - HiresW (/pub/data/nccf/com/hiresw/ - except Guam)
  - NAM MOS

2. New Model Additions (SCN 26-48):
  Next-generation high-resolution data streams are available under new operational directory paths:
  - Rapid Refresh Forecast System (RRFS v1.0): /pub/data/nccf/com/rrfs/prod/
  - RRFS Ensemble Forecast System (REFS v1.0): /pub/data/nccf/com/refs/prod/

3. Downstream & Auxiliary Updates:
  - HYSPLIT v9.1 (SCN 26-78): Inputs updated to use RRFS/GFS streams.
  - SPC Post v3.0 (SCN 26-77): Post-processing output headers and directories updated.
  - Blend & MAG Website Changes (SCN 26-89): Web visualizations and blend inputs transitioned to RRFS/REFS.

[donsutherland1]

November is poised to get off to a balmy start in the New York City area. However, around November 10th +/- few days it could turn briefly cooler. That shows up on the latest ECMWF ensembles.

It is also consistent with the weekly guidance.

The biggest uncertainty concerns the forecast weakening/possible split of the polar vortex toward mid-November. However, the ensembles favor a rapid recovery suggesting that the effects could be short-lived. Meanwhile a historically strong El Niño continues to strengthen. It will likely peak in November or possibly December. 

[MANDA]

This post from 10/23 is aging well.

Per Don post above and looking at LR guidance not seeing much if any chance of CP getting to 32 or below before 3rd week of November and at this point the odds inching up for December,

 

[NEG NAO]

45 minutes ago, donsutherland1 said:

November is poised to get off to a balmy start in the New York City area. However, around November 10th +/- few days it could turn briefly cooler. That shows up on the latest ECMWF ensembles.

It is also consistent with the weekly guidance.

The biggest uncertainty concerns the forecast weakening/possible split of the polar vortex toward mid-November. However, the ensembles favor a rapid recovery suggesting that the effects could be short-lived. Meanwhile a historically strong El Niño continues to strengthen. It will likely peak in November or possibly December. 

Judah Cohen says the models don't have a handle on this set up yet - he has an interview video which I can't post here for some reason on FOX. He is not sure what might happen yet going into December.

 

[MJO812]

1 minute ago, NEG NAO said:

Judah Cohen says the models don't have a handle on this set up yet - he has an interview video which I can't post here for some reason on FOX. He is not sure what might happen yet going into December.

 

December is so far away . No one has a clue yet that far. Long range forecasting hasn't been right in years.

[NEG NAO]

6 minutes ago, MJO812 said:

December is so far away . No one has a clue yet that far. Long range forecasting hasn't been right in years.

Correct - plus all these above average temp months in a row and this abnormally long stretch of spring/summer like weather the last couple of weeks is giving some folks a false sense of security that EL NINO will protect us from the cold and snow well into winter..............

[rclab]

1 hour ago, donsutherland1 said:

November is poised to get off to a balmy start in the New York City area. However, around November 10th +/- few days it could turn briefly cooler. That shows up on the latest ECMWF ensembles.

It is also consistent with the weekly guidance.

The biggest uncertainty concerns the forecast weakening/possible split of the polar vortex toward mid-November. However, the ensembles favor a rapid recovery suggesting that the effects could be short-lived. Meanwhile a historically strong El Niño continues to strengthen. It will likely peak in November or possibly December. 

 Accuweather long range seems to follow the same curve. As always …….

[MarcmmKU]

2 hours ago, MANDA said:

This post from 10/23 is aging well.

Per Don post above and looking at LR guidance not seeing much if any chance of CP getting to 32 or below before 3rd week of November and at this point the odds inching up for December,

 

I would not be surprised if it does not occur until late December or even January. We have a historic nino on our hands, i bet we struggle to get a sufficiently cold shot in December.

[NEG NAO]

44 minutes ago, MarcmmKU said:

I would not be surprised if it does not occur until late December or even January. We have a historic nino on our hands, i bet we struggle to get a sufficiently cold shot in December.

FYI it has never stayed above 32 degrees for the entire month of December in Central Park in recorded history and most years the first freezing temp was before December 20th. So good luck with that prediction.

[MarcmmKU]

7 minutes ago, NEG NAO said:

FYI it has never stayed above 32 degrees for the entire month of December in Central Park in recorded history and most years the first freezing temp was before December 20th. So good luck with that prediction.

Well there has never been an el nino this strong, and never been such a warm 9 months in the conus. Also LaGuardia didnt dip below 32 in December 2015. So not at all unprecented.