2024-2025 La Nina

[Stormchaserchuck1]

I probably wouldn't expect something too hot. The trend for the last 20 years has been a trough in the east/ridge in the west during the Summertime. Last year that pattern really changed, and I think we will see some year-to-year lingering effects from that this Summer. And the SW, US was +2F over their previous record last Summer! And is going to likely have a hot Spring, so some of that usually comes east +time.. I would at least expect an above average Summer in the east, and maybe comfortably so. 

[snowman19]

If the projected summer global picture (cold-neutral “Nada” ENSO coming off a La Niña, -QBO, -PMM, -PDO, still elevated solar/geomag activity) continues into the fall, I have a feeling that the winter forecast is not going to be a cut and dry easy one at all, not that any of them ever really are, but this one may be exceptionally difficult 

[PhiEaglesfan712]

36 minutes ago, snowman19 said:

If the projected summer global picture (cold-neutral “Nada” ENSO coming off a La Niña, -QBO, -PMM, -PDO, still elevated solar/geomag activity) continues into the fall, I have a feeling that the winter forecast is not going to be a cut and dry easy one at all, not that any of them ever really are, but this one may be exceptionally difficult 

Those conditions sound a lot like 2013, which of course produced a widespread cold and snowy winter in the Eastern United States.

[LibertyBell]

3 hours ago, snowman19 said:

If the projected summer global picture (cold-neutral “Nada” ENSO coming off a La Niña, -QBO, -PMM, -PDO, still elevated solar/geomag activity) continues into the fall, I have a feeling that the winter forecast is not going to be a cut and dry easy one at all, not that any of them ever really are, but this one may be exceptionally difficult 

cold neutral after la nina has historically resulted in some of our warmer winters and lower snowfall totals

1989-90 and 2001-02 come to mind

 

[GaWx]

28 minutes ago, LibertyBell said:

cold neutral after la nina has historically resulted in some of our warmer winters and lower snowfall totals

1989-90 and 2001-02 come to mind

 

-Those 2 each had a major SE snow.

-85-6 had “deep SE” snows

-Nov 1950 had alltime record Nov cold in SE

-Other: 1996-7 had nothing overly notable in SE

-1894-5 had the coldest and snowiest Feb on record in the SE

[michsnowfreak]

1 hour ago, GaWx said:

-Those 2 each had a major SE snow.

-85-6 had “deep SE” snows

-Nov 1950 had alltime record Nov cold in SE

-Other: 1996-7 had nothing overly notable in SE

-1894-5 had the coldest and snowiest Feb on record in the SE

Do you have a list of years that were cold neutral following la nina?

[Stormchaserchuck1]

8 hours ago, bluewave said:

Maybe the lack of coupling was related to what happened last summer.

Sorry - I'm not completely sure what this is saying about a disconnect. They showed a warm 30mb layer in Aug/Sept

And it was actually followed by 3 months of -NAO:

Sep: -1.43  Oct: -0.38  Nov: -0.23

Remember, at this time of the year, the warm Stratosphere, on average, takes +60 days to "downwell" (maybe less for 30mb vs 10mb). 

[GaWx]

31 minutes ago, michsnowfreak said:

Do you have a list of years that were cold neutral following la nina?

2012-3, 2001-2, 1996-7, 1985-6, 1950-1, 1943-4, 1934-5, 1894-5, 1875-6, 1870-1

[Stormchaserchuck1]

CPC actually says that last Winter was Neutral

If you take into account the global warming skew, it was a very Weak Nina. 

"Neutral" after Neutral doesn't actually mean much - it just means that ENSO is a weak signal. If this year is Neutral though, it would only be the 2nd time for back-to-back Neutral's since 93-94 (12-13 to 13-14 was the only other one). 

The back-to-back stuff has valiance because El Nino's and La Nina's warm or cool the atmosphere in lagged time, but that's less relevant this year. 

[Stormchaserchuck1]

6 hours ago, snowman19 said:

If the projected summer global picture (cold-neutral “Nada” ENSO coming off a La Niña, -QBO, -PMM, -PDO, still elevated solar/geomag activity) continues into the fall, I have a feeling that the winter forecast is not going to be a cut and dry easy one at all, not that any of them ever really are, but this one may be exceptionally difficult 

Neutral is always more difficult... What I'm going to be looking for is if there are large -500mb anomalies around the Globe this Summer.. Last year we had 9 strong +NAO bouts (cold 500mb over Greenland), and that translated +time to a cooler Winter pattern. Will be interesting to see if the pattern continues this year, but that anomaly has been less common since October 2024. 

[michsnowfreak]

5 hours ago, GaWx said:

2012-3, 2001-2, 1996-7, 1985-6, 1950-1, 1943-4, 1934-5, 1894-5, 1875-6, 1870-1

Thanks! No noticeable trends here, quite a variable dataset

[Stormchaserchuck1]

This is how the cold season Stratosphere has "coupled" since year 2000 (15 cases)

[snowman19]

CPC actually says that last Winter was Neutral

If you take into account the global warming skew, it was a very Weak Nina. 
"Neutral" after Neutral doesn't actually mean much - it just means that ENSO is a weak signal. If this year is Neutral though, it would only be the 2nd time for back-to-back Neutral's since 93-94 (12-13 to 13-14 was the only other one). 
The back-to-back stuff has valiance because El Nino's and La Nina's warm or cool the atmosphere in lagged time, but that's less relevant this year. 

I’m going to take into account the global warming skew and say this past winter was a “late bloomer” weak La Niña. There was very dramatic cooling and EWBs starting in late November/December

[LibertyBell]

20 hours ago, GaWx said:

2012-3, 2001-2, 1996-7, 1985-6, 1950-1, 1943-4, 1934-5, 1894-5, 1875-6, 1870-1

not 1989-90 though?

[LibertyBell]

20 hours ago, GaWx said:

2012-3, 2001-2, 1996-7, 1985-6, 1950-1, 1943-4, 1934-5, 1894-5, 1875-6, 1870-1

wow 1875 was a la nina? Look how snowy April 1875 was in NYC lol, four separate snowstorms including our latest on record on the 25th.

1942-43 was a la nina? It was extremely cold, -6 in February, the last time NYC was colder than -2.

I think 1893-94 was also very snowy

1933-34 was a la nina too? That had our coldest temperature on record and historically cold and snowy February.

1995-96 of course speaks for itself.

The real news here is not how the weather was in those neutral years but how much colder and snowier la ninas were in the past here!

 

[LibertyBell]

1 hour ago, snowman19 said:

I’m going to take into account the global warming skew and say this past winter was a “late bloomer” weak La Niña. There was very dramatic cooling and EWBs starting in late November/December

The real story in that dataset is how much colder and snowier la ninas of the past were!

wow 1875 was a la nina? Look how snowy April 1875 was in NYC lol, four separate snowstorms including our latest on record on the 25th.

1942-43 was a la nina? It was extremely cold, -6 in February, the last time NYC was colder than -2.

I think 1893-94 was also very snowy

1933-34 was a la nina too? That had our coldest temperature on record and historically cold and snowy February.

1995-96 of course speaks for itself.

The real news here is not how the weather was in those neutral years but how much colder and snowier la ninas were in the past here!

[GaWx]

54 minutes ago, LibertyBell said:

not 1989-90 though?

Because it was straight warming from the prior Niña and DJF was up to +0.1

[snowman19]

Because it was straight warming from the prior Niña and DJF was up to +0.1

I’m starting to gain more confidence in a cold-neutral ENSO. At this point, based on the subsurface, surface, trade winds and the -PMM, I’d say an El Niño is extremely unlikely

[GaWx]

4 hours ago, snowman19 said:

I’m starting to gain more confidence in a cold-neutral ENSO. At this point, based on the subsurface, surface, trade winds and the -PMM, I’d say an El Niño is extremely unlikely

 I agree as I see very little chance for El Niño at this point. The only thing that I recall that ever explicitly hinted at it was CANSIPS a number of months ago when looking ahead to August showing a significant central Pacific equatorial warming. However, it has since been modifying this each run and no longer shows anything of note. In addition, Nino regions have cooled notably from highs in March/earlier this month (see below). When also considering the Euro’s notable warm bias in spring for the subsequent autumn, I’d also say very low chance. La Niña may very well have a better chance than El Niño.

[michsnowfreak]

21 hours ago, LibertyBell said:

The real story in that dataset is how much colder and snowier la ninas of the past were!

wow 1875 was a la nina? Look how snowy April 1875 was in NYC lol, four separate snowstorms including our latest on record on the 25th.

1942-43 was a la nina? It was extremely cold, -6 in February, the last time NYC was colder than -2.

I think 1893-94 was also very snowy

1933-34 was a la nina too? That had our coldest temperature on record and historically cold and snowy February.

1995-96 of course speaks for itself.

The real news here is not how the weather was in those neutral years but how much colder and snowier la ninas were in the past here!

Youre looking at just a small sample of La Nina years though. Youd really want to look at the entire mean of them and see if any trends have occurred/changed along the way. Several of those winters were actually quite dry here, which strays from the typical la nina mean. 

[snowman19]

 I agree as I see very little chance for El Niño at this point. The only thing that I recall that ever explicitly hinted at it was CANSIPS a number of months ago when looking ahead to August showing a significant central Pacific equatorial warming. However, it has since been modifying this each run and no longer shows anything of note. In addition, Nino regions have cooled notably from highs in March/earlier this month (see below). When also considering the Euro’s notable warm bias in spring for the subsequent autumn, I’d also say very low chance. La Niña may very well have a better chance than El Niño.

Completely agree. I’d say right now a cold-neutral is most likely, with a lower chance of a weak La Niña. El Niño being extremely unlikely

[michsnowfreak]

I personally already like the look for next winter for the simple fact that the worst case scenario for winter here (strong El Nino) appears to be the least likely scenario for 2025-26. Multiple other things going in our favor too, but not going to get into details this early.

Also, a reminder to all that there is a 2025-26 discussion thread.

[so_whats_happening]

Latest subsurface look, lets see how things go from here. 

[George001]

1 hour ago, michsnowfreak said:

I personally already like the look for next winter for the simple fact that the worst case scenario for winter here (strong El Nino) appears to be the least likely scenario for 2025-26. Multiple other things going in our favor too, but not going to get into details this early.

Also, a reminder to all that there is a 2025-26 discussion thread.

Agreed, I hope Snowman19 is right. I’ll gladly roll the dice with ENSO neutral.

[snowman19]

Good luck getting an El Niño with this going on: