2025-2026 ENSO

[EasternLI]

Its interesting times when there's potential to see an amplified MJO in the Pacific. Then firing off an +EAMT into that. Especially given the time of year...

 

[snowman19]

One thing is for sure, this La Niña is and has been exactly mimicking a classic canonical La Niña pattern to a tee. I see absolutely no reason to think it’s going to deviate at all from such in the coming months
 

 

 

 

 

[George001]

42 minutes ago, snowman19 said:

One thing is for sure, this La Niña is and has been exactly mimicking a classic canonical La Niña pattern to a tee. I see absolutely no reason to think it’s going to deviate at all from such in the coming months
 

 

 

 

 

Agree, its no longer a debate whether or not La Niña will develop. We are below the -0.5 threshold on the weeklies in 3 of the 4 ENSO regions, pretty much all the non ONI indices are consistent with La Niña, and the CPC has announced that La Nina conditions are present. So, La Niña is already here. The question is how long does it stay intact and when does it peak? I am hearing some people argue that the La Niña will break down in January and others believe it will remain intact the entire winter. What are your thoughts here? I am very skeptical of the idea it breaks down in January. 

[snowman19]

9 minutes ago, George001 said:

Agree, its no longer a debate whether or not La Niña will develop. We are below the -0.5 threshold on the weeklies in 3 of the 4 ENSO regions, pretty much all the non ONI indices are consistent with La Niña, and the CPC has announced that La Nina conditions are present. So, La Niña is already here. The question is how long does it stay intact and when does it peak? I am hearing some people argue that the La Niña will break down in January and others believe it will remain intact the entire winter. What are your thoughts here?

I agree. We are and have been in a very well coupled La Niña, both atmospherically and oceanically. I see absolutely no evidence at all to expect anything but a canonical La Niña pattern through March. It’s been following the classic La Niña footprint since the start of October and still is. Even if we go cold-neutral come January or February/March, there is no reason to believe the Niña pattern is going to somehow magically just instantly go away. There is always a lag of months between when ENSO phases switch and when you see the effects on the atmosphere 

[michsnowfreak]

4 hours ago, FPizz said:

He's been bullish on this and several others as well as we've been reading here.

Ive said since summer im feeling a good December here. I will go down with the ship if im wrong, but now that we are getting closer, its nice to see mets/models latch onto that general idea. For the talk of a textbook La Nina....well....a textbook La Nina has a good December here, and in fact, often times December is the best month of the winter. It has been a long time since that has been the case, as January/February almost always take home the prize lately. 

[GaWx]

1 hour ago, snowman19 said:

I agree. We are and have been in a very well coupled La Niña, both atmospherically and oceanically. I see absolutely no evidence at all to expect anything but a canonical La Niña pattern through March. It’s been following the classic La Niña footprint since the start of October and still is. Even if we go cold-neutral come January or February/March, there is no reason to believe the Niña pattern is going to somehow magically just instantly go away. There is always a lag of months between when ENSO phases switch and when you see the effects on the atmosphere 

Looks like a Dec/Jan winter the way it appears now. That would be hard to beat.

[jm1220]

29 minutes ago, michsnowfreak said:

Ive said since summer im feeling a good December here. I will go down with the ship if im wrong, but now that we are getting closer, its nice to see mets/models latch onto that general idea. For the talk of a textbook La Nina....well....a textbook La Nina has a good December here, and in fact, often times December is the best month of the winter. It has been a long time since that has been the case, as January/February almost always take home the prize lately. 

Selfishly I hope you’re wrong since a great December for you means washouts here. But hopefully I get at least a decent event that gets Central Park over 4” for the month. 

[mitchnick]

8 minutes ago, GaWx said:

Looks like a Dec/Jan winter the way it appears now. That would be hard to beat.

If February was to surprise us to the positive, I doubt we see that coming before mid-January. The best weak Nina to my recollection in the MA was 95/96. But even that had a nasty thaw in January. But odds now certainly favor a lousy February, at least south of NE.

[George001]

20 minutes ago, mitchnick said:

If February was to surprise us to the positive, I doubt we see that coming before mid-January. The best weak Nina to my recollection in the MA was 95/96. But even that had a nasty thaw in January. But odds now certainly favor a lousy February, at least south of NE.

South of NE is more dicey, agree. I like Jan best, but I am not sold on a bad Feb especially for New England and possibly the northern mid atlantic. Gradient patterns can lead to big snows if you are north of the storm track. It is also looking like the polar vortex is going to be especially prone to disruptions this year. 

[40/70 Benchmark]

135.5 Final ACE

[michsnowfreak]

1 hour ago, jm1220 said:

Selfishly I hope you’re wrong since a great December for you means washouts here. But hopefully I get at least a decent event that gets Central Park over 4” for the month. 

Hey we all want snow in our backyard, so not selfish at all. Very excited for our first snow here Sunday.

[GaWx]

 Today’s Euro Weeklies run for Dec 1-7 has backed off significantly from yesterday’s run, which was the coldest run yet. It looks like the run from 2 days ago. Also, the subsequent two weeks are warmer than yesterday. All 3 weeks are now near normal in most of the E US.

Dec 1-7:

Today

 

Yesterday:

[Krs4Lfe]

15 minutes ago, GaWx said:

 Today’s Euro Weeklies run for Dec 1-7 has backed off significantly from yesterday’s run, which was the coldest run yet. It looks like the run from 2 days ago. Also, the subsequent two weeks are warmer than yesterday. All 3 weeks are now near normal in most of the E US.

Dec 1-7:

Today

 

Yesterday:

That tracks well with weeklies usually showing colder air and then correcting warmer as time gets closer. 

[40/70 Benchmark]

I would not expect a very cold Decemer, - NAO just delivers consistently pedestrian departures. You need the +TNH get really cold values...and this is assuming tha the -NAO isn't overdone, which it probably is.

[Maestrobjwa]

15 minutes ago, 40/70 Benchmark said:

I would expect a very cold Decemer, - NAO just delivers consistently pedestrian departures. You need the +TNH get really cold values...and this is assuming tha the -NAO isn't overdone, which it probably is.

Did you mean you would not expect a very cold December, then?

[MJO812]

43 minutes ago, GaWx said:

 Today’s Euro Weeklies run for Dec 1-7 has backed off significantly from yesterday’s run, which was the coldest run yet. It looks like the run from 2 days ago. Also, the subsequent two weeks are warmer than yesterday. All 3 weeks are now near normal in most of the E US.

Dec 1-7:

Today

 

Yesterday:

Looks nice

Rather show this than the deep cold which would cause suppression like last year.

[GaWx]

43 minutes ago, 40/70 Benchmark said:

I would not expect a very cold Decemer, - NAO just delivers consistently pedestrian departures. You need the +TNH get really cold values...and this is assuming tha the -NAO isn't overdone, which it probably is.

If we get that early SSWE, any E US cold affects would probably be stronger in Jan than in Dec based on typical lag time.

[stadiumwave]

4 hours ago, GaWx said:

Looks like a Dec/Jan winter the way it appears now. That would be hard to beat.

 

I am totally up for a good ol traditional frontloaded DEC to 1st half of JAN winter.

Roundy's tool updated & it looks great 1st 2 weeks of DEC & it all unravels after that. I need more than 2 weeks, lol. 

[FPizz]

5 hours ago, GaWx said:

 Today’s Euro Weeklies run for Dec 1-7 has backed off significantly from yesterday’s run, which was the coldest run yet. It looks like the run from 2 days ago. Also, the subsequent two weeks are warmer than yesterday. All 3 weeks are now near normal in most of the E US.

Dec 1-7:

Today

 

Yesterday:

How much weight do you give them if they run daily?

[Stormchaserchuck1]

9 hours ago, snowman19 said:

One thing is for sure, this La Niña is and has been exactly mimicking a classic canonical La Niña pattern to a tee. I see absolutely no reason to think it’s going to deviate at all from such in the coming months

That's a really good point -- the total N. Hemisphere 500mb pattern has been a very close match for October and November this year, about as close as it gets. 

Going forward, December typically holds the November -NAO, then the NAO switches to positive for January and February

[Stormchaserchuck1]

13 minutes ago, FPizz said:

How much weight do you give them if they run daily?

They have had pretty decent success the last few years. I believe they kept showing cold in 23-24 that never panned out, but Gawx has been posting long range ACE forecasts and they have been very good over the last 2 years. It nailed a few Stratosphere warmings in early 2024. 

[FPizz]

7 minutes ago, Stormchaserchuck1 said:

They have had pretty decent success the last few years. I believe they kept showing cold in 23-24 that never panned out, but Gawx has been posting long range ACE forecasts and they have been very good over the last 2 years. It nailed a few Stratosphere warmings in early 2024. 

I was more thinking 3 days ago vs yesterday vs today.  I dont have access, so do they change this much daily or was this a pretty big one day jump?

[Stormchaserchuck1]

12 minutes ago, FPizz said:

I was more thinking 3 days ago vs yesterday vs today.  I dont have access, so do they change this much daily or was this a pretty big one day jump?

From what I've seen Gawx post, it was a pretty big one-day jump. Like, top 15 percentile. Maybe he can confirm though. 

[stadiumwave]

NMME page is pure ugly if you like winter. 

https://www.cpc.ncep.noaa.gov/products/NMME/monanom.shtml

[stadiumwave]

SOI....climbing 

 

[GaWx]

1 hour ago, FPizz said:

I was more thinking 3 days ago vs yesterday vs today.  I dont have access, so do they change this much daily or was this a pretty big one day jump?

 

1 hour ago, Stormchaserchuck1 said:

From what I've seen Gawx post, it was a pretty big one-day jump. Like, top 15 percentile. Maybe he can confirm though. 

 I of course don’t post every day’s runs. But because I posted yesterday’s significantly colder week 4, I felt obligated to post today’s significantly warmer week 4 so as to not appear one-sided.

 Chuck’s guess that that was a top 15 percentile jump is as reasonable an educated guess as any. So, it was a “pretty big jump” as he said though nothing at all extreme, especially considering that’s still out at week 4. Consider how much colder it got for early next week on all models since that was during only week 2!

 So, considering all of this and the inherent unpredictability out a month, sig. jumps that far out on any long range ensemble are pretty common and shouldn’t ever be surprising.

 

[GaWx]

6 hours ago, Krs4Lfe said:

That tracks well with weeklies usually showing colder air and then correcting warmer as time gets closer. 

I don’t think this is true. Now if they had a cold bias, that would be true.

[stadiumwave]

15 minutes ago, GaWx said:

 

 I of course don’t post every day’s runs. But because I posted yesterday’s significantly colder week 4, I felt obligated to post today’s significantly warmer week 4 so as to not appear one-sided.

 Chuck’s guess that that was a top 15 percentile jump is as reasonable an educated guess as any. So, it was a “pretty big jump” as he said though nothing at all extreme, especially considering that’s still out at week 4. Consider how much colder it got for early next week on all models since that was during only week 2!

 So, considering all of this and the inherent unpredictability out a month, sig. jumps that far out on any long range ensemble are pretty common and shouldn’t ever be surprising.

 

 

What did the EPS SPV forecast look like today?

[Stormchaserchuck1]

22 minutes ago, stadiumwave said:

SOI....climbing 

30-day is the highest since December 2022! It had actually gone 31 straight months without passing +10, now it's up to +15. Between that, the Oct-Nov N. Hemisphere 500mb pattern, and now a -3c pocket developing in the ENSO subsurface.. you can make a case for a La Nina presence this Winter. I'm curious to see how it goes with the fact that 21 of the last 29 months have been +PNA (CPC), and what happens there going forward. 

[GaWx]

8 minutes ago, stadiumwave said:

 

What did the EPS SPV forecast look like today?

Similar to yesterday meaning Wednesday’s run (mean dipped to only +7) remains the weakest:

 

Wed. run: