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. 

[bluewave]

On 4/17/2025 at 1:52 PM, Stormchaserchuck1 said:

Yeah, in my Winter forecast I got the state of 10mb correct (from +QBO and La Nina), but didn't get that it would translate to -AO at the surface.. about 75% of the time the AO is the same state as 10mb. 

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

 

 

[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)