2025-2026 ENSO

[GaWx]

30 minutes ago, donsutherland1 said:

In general, a PNA- pattern results in lighter snowfalls in the New York City area and northern Mid-Atlantic. The Boxing Day blizzard is a notable exception and the only KU snowstorm during December when the PNA was negative.

Hey Don,

 This is somewhat related and something I happened to compile yesterday about big NC snowstorms during -PNAs. First, note that the -PNA for the 2010 storm was only weak (-0.3). Also, what’s interesting about the list below of big NC snows during a -PNA is that only one of the 7 most -PNA 6”+ storms there were during a -NAO! Anyone know why or is this likely just from randomness? It’s a somewhat decent sized sample of 7 and 4 of the 7 had a moderate to strong +NAO as opposed to just a weak +NAO:

6”+ storms since 1950 at GSO and/or RDU: most negative PNA:

-1.1: 2/12-13/2014 (moderate +NAO)
-0.8: 1/22-24/1954 (moderate +NAO)
-0.8: 3/2-3/1960 (neutral NAO)
-0.7: 1/6-7/2017 (moderate +NAO)
-0.5: 3/9/1960 (neutral NAO)
-0.3: 12/26/2010 (moderate -NAO)
-0.3: 2/24-26/2015 (strong +NAO)

Daily PNA:

https://ftp.cpc.ncep.noaa.gov/cwlinks/norm.daily.pna.index.b500101.current.ascii

Daily NAO:

https://ftp.cpc.ncep.noaa.gov/cwlinks/norm.daily.nao.index.b500101.current.ascii

 

 

[EastonSN+]

3 minutes ago, GaWx said:

Hey Don,

 This is somewhat related and something I happened to compile yesterday about big NC snowstorms during -PNAs. First, note that the -PNA for the 2010 storm was only weak (-0.3). Also, what’s interesting about the list below of big NC snows during a -PNA is that only one of the 7 most -PNA 6”+ storms there were during a -NAO! Anyone know why or is this likely just from randomness? It’s a somewhat decent sized sample of 7 and 4 of the 7 had a moderate to strong +NAO as opposed to just a weak +NAO:

6”+ storms since 1950 at GSO and/or RDU: most negative PNA:

-1.1: 2/12-13/2014 (moderate +NAO)
-0.8: 1/22-24/1954 (moderate +NAO)
-0.8: 3/2-3/1960 (neutral NAO)
-0.7: 1/6-7/2017 (moderate +NAO)
-0.5: 3/9/1960 (neutral NAO)
-0.3: 12/26/2010 (moderate -NAO)
-0.3: 2/24-26/2015 (strong +NAO)

Daily PNA:

https://ftp.cpc.ncep.noaa.gov/cwlinks/norm.daily.pna.index.b500101.current.ascii

Daily NAO:

https://ftp.cpc.ncep.noaa.gov/cwlinks/norm.daily.nao.index.b500101.current.ascii

 

 

[GaWx]

16 minutes ago, EastonSN+ said:

 Yeah, way out in fantasyland! This reminds me of this Euro storm from last January in not as far out fantasyland:

  
 While this was gone on the very next run, this turned out to be when the historic 1/21-2/2025 Gulf coast/deep SE winter storm occurred.

[EastonSN+]

8 minutes ago, GaWx said:

 Yeah, way out in fantasyland! This reminds me of this Euro storm from last January I’m not as far out fantasyland:

  
 While this was gone on the very next run, this turned out to be when the historic 1/21-2/2025 Gulf coast/deep SE winter storm occurred.

If the NAO is as strong as predicted, it would favor southern areas. The boxing day blizzard also hit NC hard.

[donsutherland1]

30 minutes ago, GaWx said:

Hey Don,

 This is somewhat related and something I happened to compile yesterday about big NC snowstorms during -PNAs. First, note that the -PNA for the 2010 storm was only weak (-0.3). Also, what’s interesting about the list below of big NC snows during a -PNA is that only one of the 7 most -PNA 6”+ storms there were during a -NAO! Anyone know why or is this likely just from randomness? It’s a somewhat decent sized sample of 7 and 4 of the 7 had a moderate to strong +NAO as opposed to just a weak +NAO:

6”+ storms since 1950 at GSO and/or RDU: most negative PNA:

-1.1: 2/12-13/2014 (moderate +NAO)
-0.8: 1/22-24/1954 (moderate +NAO)
-0.8: 3/2-3/1960 (neutral NAO)
-0.7: 1/6-7/2017 (moderate +NAO)
-0.5: 3/9/1960 (neutral NAO)
-0.3: 12/26/2010 (moderate -NAO)
-0.3: 2/24-26/2015 (strong +NAO)

Daily PNA:

https://ftp.cpc.ncep.noaa.gov/cwlinks/norm.daily.pna.index.b500101.current.ascii

Daily NAO:

https://ftp.cpc.ncep.noaa.gov/cwlinks/norm.daily.nao.index.b500101.current.ascii

 

 

I suspect that when it comes to snowstorms in parts of the Southeast, more is involved than the pattern itself. Synoptic details are critical and outweigh the teleconnections. One sees a similar outcome in the spring in the Middle Atlantic region as wave lengths shorten and the state of the teleconnections becomes less important.

[SnowGoose69]

49 minutes ago, donsutherland1 said:

While the AO and NAO are looking good on the latest GEFS, the PNA is not.

It’s going to be a battle in January I think of which one gives in first.  If it’s the NAO winter is probably done for if we assume we get the February most expect we do based on the IOD/ENSO.  If it’s the PNA maybe we can get a crazy 2-3 weeks.  I’d still lean towards February probably being bad but in La Niña to El Niño transition years we’ve seen March sometimes be good  

[donsutherland1]

46 minutes ago, GaWx said:

Hey Don,

 This is somewhat related and something I happened to compile yesterday about big NC snowstorms during -PNAs. First, note that the -PNA for the 2010 storm was only weak (-0.3). Also, what’s interesting about the list below of big NC snows during a -PNA is that only one of the 7 most -PNA 6”+ storms there were during a -NAO! Anyone know why or is this likely just from randomness? It’s a somewhat decent sized sample of 7 and 4 of the 7 had a moderate to strong +NAO as opposed to just a weak +NAO:

6”+ storms since 1950 at GSO and/or RDU: most negative PNA:

-1.1: 2/12-13/2014 (moderate +NAO)
-0.8: 1/22-24/1954 (moderate +NAO)
-0.8: 3/2-3/1960 (neutral NAO)
-0.7: 1/6-7/2017 (moderate +NAO)
-0.5: 3/9/1960 (neutral NAO)
-0.3: 12/26/2010 (moderate -NAO)
-0.3: 2/24-26/2015 (strong +NAO)

Daily PNA:

https://ftp.cpc.ncep.noaa.gov/cwlinks/norm.daily.pna.index.b500101.current.ascii

Daily NAO:

https://ftp.cpc.ncep.noaa.gov/cwlinks/norm.daily.nao.index.b500101.current.ascii

 

 

Here's some data for NYC for January and March (1980-2025):

[GaWx]

1 hour ago, donsutherland1 said:

While the AO and NAO are looking good on the latest GEFS, the PNA is not.

 I’m very curious to see what happens in Jan with the PNA based on -ENSO strong Dec -PNA analogs like 2021, 2013, 2010, 2008, and 1984 whose Jan PNA all rose 1.8++ from Dec. That’s still well beyond what models can see with any notable degree of skill. My GEFS PNA forecasting images for Dec 2021-Jan 2022 displayed that well.

[SnowGoose69]

3 minutes ago, GaWx said:

 I’m very curious to see what happens in Jan with the PNA based on -ENSO strong Dec -PNA analogs like 2021, 2013, 2010, 2008, and 1984 whose Jan PNA all rose 1.8++ from Dec. That’s still well beyond what models can see with any notable degree of skill.

00 and 97 I think also went pretty strong +PNA I think but can’t recall if they were negative in December or not.  I want to say they were not 

[GaWx]

13 minutes ago, SnowGoose69 said:

00 and 97 I think also went pretty strong +PNA I think but can’t recall if they were negative in December or not.  I want to say they were not 

-Actually, Dec of 1996, indeed, was still another -ENSO strong -PNA that transitioned to a +PNA in Jan after a 1.8+ rise.

-Dec of 1999 had a neutral PNA. So, that isn’t in this group.

*Corrected for typo…Dec of 1999

[donsutherland1]

31 minutes ago, GaWx said:

 I’m very curious to see what happens in Jan with the PNA based on -ENSO strong Dec -PNA analogs like 2021, 2013, 2010, 2008, and 1984 whose Jan PNA all rose 1.8++ from Dec. That’s still well beyond what models can see with any notable degree of skill. My GEFS PNA forecasting images for Dec 2021-Jan 2022 displayed that well.

It will be interesting to see how things evolve. Since 1980, December PNA- cases have been followed by January PNA+ cases. Prior to 1980, December PNA- cases were generally followed by January PNA- cases. It is possible that the less stable PNA state is, at least in part, a result of Arctic amplification.

[Maestrobjwa]

1 hour ago, donsutherland1 said:

It will be interesting to see how things evolve. Since 1980, December PNA- cases have been followed by January PNA+ cases. Prior to 1980, December PNA- cases were generally followed by January PNA- cases. It is possible that the less stable PNA state is, at least in part, a result of Arctic amplification.

I'm curious to see the resulting snow results for BWI & NYC after those PNA spike years...but off the top of my head it seems only two ninos and 13-14 produced down this way. -ENSO was all below average.

[donsutherland1]

22 minutes ago, Maestrobjwa said:

I'm curious to see the resulting snow results for BWI & NYC after those PNA spike years...but off the top of my head it seems only two ninos and 13-14 produced down this way. -ENSO was all below average.

For Baltimore:

[GaWx]

 On 12/26/21, when the PNA had been negative all month/way down at -1.8 that day and Baltimore (among others) had just had a miserably mild 68F Christmas high with very mild to continue through New Year’s, this (see image below) was the 12/26/21 GEFS two week PNA forecast, which went to 1/9/22: still down at -0.6 on 1/9/22 and no clearcut sign that 1/9/22 was going to be the start of a 38 day long +PNA as well as Jan ending up the snowiest month by far there since Jan of 2016 along with it being the coldest month since Jan of 2018:

@donsutherland1

*Edit: The main points are:
- The models can’t see out that far with notable skill and that includes forecasting the PNA/general patterns
- -ENSO -PNA Decembers since 1984 all transitioned to +PNA Jans

[snowman19]

3 hours ago, SnowGoose69 said:

It’s going to be a battle in January I think of which one gives in first.  If it’s the NAO winter is probably done for if we assume we get the February most expect we do based on the IOD/ENSO.  If it’s the PNA maybe we can get a crazy 2-3 weeks.  I’d still lean towards February probably being bad but in La Niña to El Niño transition years we’ve seen March sometimes be good  

The modeling (ensembles/operationals) this afternoon is showing a decidedly east-based -NAO going into the beginning of January, also still holding on to the -PNA as well. If the true east-based -NAO is correct, it would be quite the change from what we have seen over the last 10 years or so with -NAO’s, 

[donsutherland1]

21 minutes ago, GaWx said:

 On 12/26/21, when the PNA had been negative all month/way down at -1.8 that day and Baltimore (among others) had just had a miserably mild 68F Christmas high with very mild to continue through New Year’s, this (see image below) was the 12/26/21 GEFS two week PNA forecast, which went to 1/9/22: still down at -0.6 on 1/9/22 and no clearcut sign that 1/9/22 was going to be the start of a 38 day long +PNA as well as Jan ending up the snowiest month by far there since Jan of 2016 along with it being the coldest month since Jan of 2018:

@donsutherland1

*Edit: The main points are:
- The models can’t see out that far with notable skill and that includes forecasting the PNA/general patterns
- -ENSO -PNA Decembers since 1984 all transitioned to +PNA Jans

Very interesting archived forecast. Is this information publicly-accessible and, if so, do you have a link?

[michsnowfreak]

I frequently hear new englanders complain of the Grinch storm, a storm/temps right around Christmas that melt away a true White Christmas. We got our taste of that today. Snow has been on the ground since November 29th....but a Grinch showed up 1 week before Christmas today. Fortunately, the Christmas season is more than just the 25th, but its very impressive to see the extreme temps the CONUS has seen this month, both way below and way above avg. It bares repeating, this is a trademark of a traditional La Nina. Last year we heard that it "didnt act" like a Nina. This winter seems to be acting just like a Nina.

One analog year that Ive not seen thrown around, but this winter is somewhat resembling so far (at least through the forecasted end of December) is 1964-65.

 

[jconsor]

5 hours ago, donsutherland1 said:

In general, a PNA- pattern results in lighter snowfalls in the New York City area and northern Mid-Atlantic. The Boxing Day blizzard is a notable exception and the only KU snowstorm during December when the PNA was negative.

True, but we just had a snowstorm produce widespread 6-8"+ from I-95 south and east (other than lighter amounts in the urban heat island near NYC) with -PNA, though in that case the NAO was slightly positive and AO highly positive.

*If* we are going to see a 6"+ snowstorm in a -PNA pattern during a La Nina, it almost definitely will come from northern stream system e.g. a highly amplified clipper/Miller B.

[GaWx]

1 hour ago, donsutherland1 said:

Very interesting archived forecast. Is this information publicly-accessible and, if so, do you have a link?

 I have it by luck on my phone as I happened to start saving a few in Dec of 2021 and Jan of 2022 I think because of long range hints on the CFS (of all models, which I also saved a bunch of…so kudos to the CFS then!) starting to show very long range big colder changes in late Dec and especially Jan. Since then, I happened to have saved a lot near and after the 2/16/2023 SSWE, which showed that the -NAO/-AO were initially way underdone/missed. Since then I’ve saved a bunch during the winters.

 I’m not aware of these being available to the public.

[GaWx]

 Todays Euro Weeklies are still not great by any means but they are a bit colder/less mild during 3 weeks of the 4 weeks starting with week 2:

12/29-1/4 yesterday

 

12/29-1/4 today

1/12-18 yesterday

 

1/12-18 today

 

1/5-11 was also a little colder today

**Edited for corrections needed in my captioning because I had “today” and “yesterday” reversed. Today’s are less mild as I said.

[michsnowfreak]

10 minutes ago, GaWx said:

 Todays Euro Weeklies are still not great by any means but they are a bit colder/less mild during 3 weeks of the 4 weeks starting with week 2:

12/29-1/4 today

 

12/29-1/4 yesterday:

1/12-18 today:

 

1/12-18 yesterday:

 

1/5-11 was also a little colder today

You have today and yesterday mixed up.

 

[donsutherland1]

1 hour ago, GaWx said:

 I have it by luck on my phone as I happened to start saving a few in Dec of 2021 and Jan of 2022 I think because of long range hints on the CFS (of all models, which I also saved a bunch of…so kudos to the CFS then!) starting to show very long range big colder changes in late Dec and especially Jan. Since then, I happened to have saved a lot near and after the 2/16/2023 SSWE, which showed that the -NAO/-AO were initially way underdone/missed. Since then I’ve saved a bunch during the winters.

 I’m not aware of these being available to the public.

Thank you. I've never seen a link. 

[SnowGoose69]

3 hours ago, snowman19 said:

The modeling (ensembles/operationals) this afternoon is showing a decidedly east-based -NAO going into the beginning of January, also still holding on to the -PNA as well. If the true east-based -NAO is correct, it would be quite the change from what we have seen over the last 10 years or so with -NAO’s, 

Europe has not been cold in seemingly forever in winter.  Thats the pattern that really gets them cold, though they did well in 09-10 and 10-11 (early) with a W based -NAO, overall the e based one is better though.

[EasternLI]

Doubt anyone anywhere sees much of any NAO blocking, unless an actual Scandinavian block happens first. The open ridges rolling over won't work for anyone. Including Europe. Models and ensembles still all over the place with that too. And that's something starting towards day 7 at this point. Need it to happen...

[GaWx]

On 12/17/2025 at 6:48 PM, GaWx said:

Ladies and gentlemen, can I have your attention, please? The results are in and we did it. The MJO went back into phase 8 on Dec 15th, the coldest day of the season to date! Let the celebrations begin! The weenies are gonna party like it’s Feb 1899!

 

Talk about a turnaround! After one day of glee and bigtime celebration due to our immense accomplishment of getting phase 8 back, it’s already gone. The MJO moved into phase 7 two days ago. Turn out the lights, the party’s over (well as of two days ago at least). 
 

 

 

But the good news is that the models are suggesting a good chance this moved right back into 8 either yesterday or today! So, we might go right back to celebrating as early as tomorrow! 

[Krs4Lfe]

It just seems like the central US ridge has strengthened as we get closer to the date. Around a week ago, we knew there would be warmth across much of conus. But this record breaking warmth for much of south and central US appears to have creeped up on us, and the duration of it seems to extend past Christmas now. I think we’ll need a jet extension (I know how much we hate those) to push storminess ashore and get some storms moving throuhh CONUS. I’d rather take my chances with stormy weather and hope there’s a well timed cold air injection than to have wall to wall torch with the only winter weather being north of the border. Doesn’t get much worse than this 

[Krs4Lfe]

2 minutes ago, GaWx said:

Talk about a turnaround! After one day of glee and bigtime celebration due to our immense accomplishment of getting phase 8 back, it’s already gone. The MJO moved into phase 7 two days ago. Turn out the lights, the party’s over (well as of two days ago at least). 
 

 

The projected cold weather between Christmas and new years is quickly slipping away. Hopefully we can get a pattern reset in early January akin to January 2024 because that shook things up quite a bit and prevented a January-March 2023 repeat with an eastern ridge. Something will have to give at some point, or that’s quite the headfake the models were throwing at us 

[GaWx]

26 minutes ago, Krs4Lfe said:

The projected cold weather between Christmas and new years is quickly slipping away. Hopefully we can get a pattern reset in early January akin to January 2024 because that shook things up quite a bit and prevented a January-March 2023 repeat with an eastern ridge. Something will have to give at some point, or that’s quite the headfake the models were throwing at us 

Well, I just added something to my last post that may cheer you up. The models are actually suggesting a good chance this moved right back into 8 either yesterday or today! So, we might go right back to celebrating as early as tomorrow!

[so_whats_happening]

10 hours ago, donsutherland1 said:

Very interesting archived forecast. Is this information publicly-accessible and, if so, do you have a link?

Ill ask my work colleague as I am also interested if there is something out there. I don't see why there wouldn't be. I start vacation this weekend into the new year so I'll have free time to finally catch up on things online (thankfully). I know I keep saying this but I will set up the thread this weekend to chat about RONI.

Im still surprised so many folks are caught off guard by this warm up and the potential of it being an extensive one at that, I wouldn't go as far as to say we are 'torching' but some areas especially in the southern plains and even lower midwest could hit record territory. Been beating this warm drum since about the beginning of the month.

Even with the prospects of a deep -NAO coming up this does not cause any bit of a cooldown for much of the east after christmas into the new year, as should be expected. I would not be surprised to see temps get to average if not slightly below average a few times during the week before the end of the year but overall much of the cold that has been across the eastern 1/3rd of the country should take a solid beating on the monthly scale. The cold is locked in Alaska and NW Canada I do expect as we get into the new year and especially after the first week for us to push a more normal state temp wise and eventually that cold should dislodge and make a run into the CONUS. 

We should know the models have a hard time grasping these types of pattern evolving (the potential retrogression) just like they tend to rush a -NAO out much quicker than reality suggests.

[so_whats_happening]

9 minutes ago, so_whats_happening said:

Ill ask my work colleague as I am also interested if there is something out there. I don't see why there wouldn't be. I start vacation this weekend into the new year so I'll have free time to finally catch up on things online (thankfully). I know I keep saying this but I will set up the thread this weekend to chat about RONI.

Im still surprised so many folks are caught off guard by this warm up and the potential of it being an extensive one at that, I wouldn't go as far as to say we are 'torching' but some areas especially in the southern plains and even lower midwest could hit record territory. Been beating this warm drum since about the beginning of the month.

Even with the prospects of a deep -NAO coming up this does not cause any bit of a cooldown for much of the east after christmas into the new year, as should be expected. I would not be surprised to see temps get to average if not slightly below average a few times during the week before the end of the year but overall much of the cold that has been across the eastern 1/3rd of the country should take a solid beating on the monthly scale. The cold is locked in Alaska and NW Canada I do expect as we get into the new year and especially after the first week for us to push a more normal state temp wise and eventually that cold should dislodge and make a run into the CONUS. 

We should know the models have a hard time grasping these types of pattern evolving (the potential retrogression) just like they tend to rush a -NAO out much quicker than reality suggests.

I hate to even be abhorrent to the idea of a retrogression but this is not the first time models have shown a Scandi like ridging pattern and no actual retrogression took place. I do hope that it comes to fruition but I think the Nina background state is still causing issues overall. The flow is just too damn fast even with the -WPO in the tank.

I think what this could at least open up for us in the east is the potential of more precip east of the rockies and then we play the game of can it happen with cold air still holding on enough to allow snowfall. We can't keep this dry train going.