2024-2025 La Nina

[Terpeast]

On 2/15/2024 at 1:36 AM, Terpeast said:

Even if this La Nina stays weak-moderate, the surrounding warmth of the oceans and the West Pac will create a very strong La Nina state much like 2022-23. 

With a +QBO and solar cycle beginning to descend, we will likely have less blocking than even 2022-23. With all the cold air bottled up at the pole/Siberia or again dumping to the western NA, I'm thinking AN to much AN temps across the entire CONUS except maybe near normal over the Pac NW. East coast will likely be much AN+++ with 60s being commonplace, with strings of 70 degree days interspersed throughout even the deepest winter months. 

Warmest winter on record across the east? Even higher chance of that happening than this year and last year. 

I know it’s way early, but CFS is thinking along similar lines for January. 

 

Cansips DJF

[PhiEaglesfan712]

[thunderbolt]

On 4/17/2024 at 8:21 PM, Terpeast said:

I know it’s way early, but CFS is thinking along similar lines for January. 

 

Cansips DJF

Really

[GaWx]

3 hours ago, thunderbolt said:

Really

It’s deceptive because this CANSIPS DJF (based on 1981-2010 base) is actually sig colder than last winter from Midwest to MidATL to NE with all areas forecasted within +1 to +4F vs last winter’s +4 to +12F! 
 Ex: Chi was +8 and is forecasted to be only +3

 NYC/DC were +5 and fcast is for only +2

 Of course it remains to be seen whether these forecasts are once again going to end up too cold. Still, a place like Chi has an excellent chance to not be nearly as warm as last winter.

[PhiEaglesfan712]

If we're using the RONI, then 2010 is the best fit year. Both el nino peaks were about the same, and at the same time. It looks like this year is falling at a faster rate. (Next best fit year would be 1988, but that el nino peaked earlier in the season.)

NDJ 2009   1.57 DJF 2010   1.45 JFM 2010   1.09 

OND 2023   1.49 NDJ 2023   1.47 DJF 2024   1.21 JFM 2024   0.86 

JAS 1987   1.47 ASO 1987   1.43 SON 1987   1.24 OND 1987   1.02 NDJ 1987   0.93 
DJF 1988   0.65 JFM 1988   0.30 

RONI peaks for the 1988-89 and 2010-11 La Ninas.

OND 1988  -1.92 NDJ 1988  -1.93 

SON 2010  -1.70 OND 2010  -1.70 

My guess is that the RONI peaks around -1.8 in late fall (SON/OND).

[CAPE]

CanSIPS h5 look suggests late Dec into early Jan and again in late winter will offer chances for colder airmasses in the central/eastern US mostly via the NE Pac ridge shifting into the EPO domain. Recent Ninas have featured such favorable periods for cold/snow in the MA, within the overall unfavorable h5 pattern for DJFM- in particular 2016-17, 17-18, and 21-22.

[PhiEaglesfan712]

[csnavywx]

On 4/19/2024 at 10:51 PM, GaWx said:

It’s deceptive because this CANSIPS DJF (based on 1981-2010 base) is actually sig colder than last winter from Midwest to MidATL to NE with all areas forecasted within +1 to +4F vs last winter’s +4 to +12F! 
 Ex: Chi was +8 and is forecasted to be only +3

 NYC/DC were +5 and fcast is for only +2

 Of course it remains to be seen whether these forecasts are once again going to end up too cold. Still, a place like Chi has an excellent chance to not be nearly as warm as last winter.

Yeah, don't think I'd put too much stock in a full on torch here yet. I was totally ready for one last winter with a strong/super EP Nino dominating. With the STJ weakened under a strong Nina, the real player will be the AO/NAO and a strong N-S gradient. It's just a question of where that gradient wants to set up.

[Stormchaserchuck1]

First sign of a La Nina -PNA pattern on todays 18z GEFS

[GaWx]

 

[GaWx]

 The 4/26/24 WCS PDO was -1.12, which is equivalent to a NOAA PDO of ~~-2.0:
 

[michsnowfreak]

On 4/17/2024 at 8:21 PM, Terpeast said:

I know it’s way early, but CFS is thinking along similar lines for January. 

 

Cansips DJF

Cfs will literally change 100+ times before then.

[Terpeast]

4 minutes ago, michsnowfreak said:

Cfs will literally change 100+ times before then.

Yes it will. But this depiction, in my opinion, is well supported by the combination of the projected nina + neg PDO + marine heat wave off Japan.

[TheClimateChanger]

10 hours ago, Terpeast said:

Yes it will. But this depiction, in my opinion, is well supported by the combination of the projected nina + neg PDO + marine heat wave off Japan.

Agreed. Looks very reasonable.

[FPizz]

Glad we figured next winter out early, that's that.

[GaWx]

 Fwiw for next winter (I know forecast value is low), the new CANSIPS pretty much maintains the -PDO/WPAC marine heatwave/basin wide to central based La Niña/-PNA/+EPO of the prior run though all but -PDO/WPAC marine heatwave with less intensity. Also, it lost the +AO/+NAO to go neutral to slightly -AO/-NAO. Temperatures in the E US went (vs cooler base of 1981-2010) from a somewhat solid AN on the prior run to very slightly AN to NN on the new one. This is equivalent to NN vs 1991-2020 base. It cooled ~2 F. Again, fwiw and I’ll believe it will be that “cool” when I see it (due to model cold bias and very low accuracy that far out):

New 2 meter DJF E US:

https://www.tropicaltidbits.com/analysis/models/?model=cansips&region=eus&pkg=T2maMean_month&runtime=2024050100&fh=9

 

Old:

https://www.tropicaltidbits.com/analysis/models/?model=cansips&region=eus&pkg=T2maMean_month&runtime=2024040100&fh=10

[roardog]

This thread is quiet compared to the El Niño thread last year. I guess Snowman19 doesn’t care about La Niña. I thought he would be around, especially with the chance that the coming Nina could be fairly strong. 

[GaWx]

On 5/1/2024 at 12:32 PM, roardog said:

This thread is quiet compared to the El Niño thread last year. I guess Snowman19 doesn’t care about La Niña. I thought he would be around, especially with the chance that the coming Nina could be fairly strong. 

 The overall lower level of posting is likely because the prospects for warmth next winter in the E US appear higher to many than it looked a year ago for 2023-4. I’m still posting and will continue to because I enjoy forecast discussions regardless of what the prospects are for whatever. But I’m much less excited than last year for a shot at a non-warm winter (though winter is still my favorite season).

 Snowman may post more later for all we know. However, there’s less incentive this year because he’d no longer be the near lone dissenting voice as folks like me would largely agree with him now. Last year he had raindance and sometimes Chuck and George but hardly anyone else as I recall. In other words, it is closer to an echo chamber so far this year. So, who would he preach good chance of a warm winter to if many of us are already believers? (That said, nothing in the wacky world of wx is ever close to being set in stone.)

 
 In case you haven’t seen it yet you can go to the NYC region’s banter thread to see him, myself, donsutherland, bluewave, and others if you want to see some recent more active longterm forecast discussions. These discussions aren’t particularly aimed at the NYC region as they’re about the E US in general.

[Stormchaserchuck1]

Really nice -PDO pattern in the N. Pacific for the next 15 days (as per 18z GEFS). 

Fitting the La Nina evolution pretty well. 

[mitchnick]

On 5/1/2024 at 12:08 PM, GaWx said:

 Fwiw for next winter (I know forecast value is low), the new CANSIPS pretty much maintains the -PDO/WPAC marine heatwave/basin wide to central based La Niña/-PNA/+EPO of the prior run though all but -PDO/WPAC marine heatwave with less intensity. Also, it lost the +AO/+NAO to go neutral to slightly -AO/-NAO. Temperatures in the E US went (vs cooler base of 1981-2010) from a somewhat solid AN on the prior run to very slightly AN to NN on the new one. This is equivalent to NN vs 1991-2020 base. It cooled ~2 F. Again, fwiw and I’ll believe it will be that “cool” when I see it (due to model cold bias and very low accuracy that far out):

New 2 meter DJF E US:

https://www.tropicaltidbits.com/analysis/models/?model=cansips&region=eus&pkg=T2maMean_month&runtime=2024050100&fh=9

 

Old:

https://www.tropicaltidbits.com/analysis/models/?model=cansips&region=eus&pkg=T2maMean_month&runtime=2024040100&fh=10

There was speculation last fall that the volcano that ejected all that water vapor would cause a strong PV for the winter. That wasn't the case and it was below normal almost the entire winter. We'll need that again and hope for some weakening of the PDO to have a better winter. Worldwide ocean temps are going to be much cooler than last year which should help fwiw.

[40/70 Benchmark]

5 hours ago, mitchnick said:

There was speculation last fall that the volcano that ejected all that water vapor would cause a strong PV for the winter. That wasn't the case and it was below normal almost the entire winter. We'll need that again and hope for some weakening of the PDO to have a better winter. Worldwide ocean temps are going to be much cooler than last year which should help fwiw.

That is one aspect that I nailed...I confidently called BS on that. However, we are beginning to reach the point in the solar cycle that is very favorable for potent PVs. We can maybe squeeze one more season before its up uphill battle for a few years in that respect.

I would be pretty suprised if next season isn't somewhat better than last season, but that isn't saying much. The cooler oceans should help a bit.

[PhiEaglesfan712]

The FMA numbers from NOAA are in. 2010 is still the best analog year for the RONI.

                NDJ 2009   1.57 DJF 2010   1.45 JFM 2010   1.09 FMA 2010   0.62 

OND 2023   1.49 NDJ 2023   1.47 DJF 2024   1.21 JFM 2024   0.85 FMA 2024   0.48 

[GaWx]

1 hour ago, PhiEaglesfan712 said:

The FMA numbers from NOAA are in. 2010 is still the best analog year for the RONI.

                NDJ 2009   1.57 DJF 2010   1.45 JFM 2010   1.09 FMA 2010   0.62 

OND 2023   1.49 NDJ 2023   1.47 DJF 2024   1.21 JFM 2024   0.85 FMA 2024   0.48 

 So, FMA RONI was 0.48 vs FMA ONI’s 1.15. That means that the FMA ONI-RONI just hit a new record high of 0.67 breaking the previous record of 0.64 just set in JFM.