2024-2025 La Nina

[FPizz]

22 minutes ago, 40/70 Benchmark said:

Who hyped this? I think maybe JB....but I didn't see anyone else. Judah never did...I though it would be useless daying back to last fall.

He has an unhealthy obsession with JB.  JB gets like 1 reply on his X posts.  No one cares about him anymore.

[snowman19]

25 minutes ago, 40/70 Benchmark said:

Who hyped this? I think maybe JB....but I didn't see anyone else. Judah never did...I though it would be useless daying back to last fall.

JB, Mark Margavage and a several others on twitter

[40/70 Benchmark]

2 minutes ago, snowman19 said:

JB, Mark Margavage and a several others on twitter

Moregarbgage....all of the idiots....yup.

I didn't see anyone worthy of actual consdieration do it.

[michsnowfreak]

1 hour ago, FPizz said:

He has an unhealthy obsession with JB.  JB gets like 1 reply on his X posts.  No one cares about him anymore.

JB has always had his cold/snowy bias, but he hasnt been relevant in years. I dont think anyone actually takes him seriously anymore lol. Following anyone (whether its via weather forums, twitter, social media weather pages, etc) with a long enough posting history makes it pretty easy to see who has the cold biases, who has the warm biases, and who is very neutral/unbiased. I follow the neutral guys closely and dismiss the rest.

[Stormchaserchuck1]

Stratosphere warming is still going strong.. one of the strongest ones in history, actually, because it's having these +1800dm anomalies cover 3-4 weeks. I think the highest I ever saw 10mb get historically on a daily was +2900dm. 

Latest daily map

3-10 is about when it started.. last 22 days:

It will probably last for another week. 

[SnoSki14]

13 hours ago, FPizz said:

He has an unhealthy obsession with JB.  JB gets like 1 reply on his X posts.  No one cares about him anymore.

He went full MAGA conspiracy nut. 

[so_whats_happening]

18 hours ago, snowman19 said:

After all the SSWE hype the end of February and throughout March, the mid-March event failed to couple, as was the case with every other stratospheric wave reflection and stretching event that has occurred since November. The stratosphere and troposphere have remained totally uncoupled
 

'It shows that the stratosphere is not an overpowering force that can be relied upon for anticipating surface weather tendencies 3+ weeks ahead.' 

I feel this is not the best take with this as sometimes it does actually overwhelm the troposphere and dictates what the setup looks like, it does not happen often as to expect it with every stratospheric warming event but it happens enough to be noticeable. There is still a lot to be learned about how the different layers interact with each other and will be interesting to learn as we go on, Don has pointed this out in several posts as well.

My best take with everything stratosphere is typically it is started through patterns evolving within the troposphere that leads to these stratospheric disruptions, whether it is a split over a large wave 1 displacement that destroys the SPV is up to how everything evolves. We saw this year just like last year we had a fairly large wave 1 displacement leading to the weakening (this year being a total quick destruction) of the SPV.

The pattern at 500mb then evolves over time to the familiar we usually associate with warm west/ cool east and that stratospheric warming can either enhance/ lock this pattern or let it play out and evolve to a relaxation period which typically allows for flattening out or a flip flop of cool west/ warm east.

While we have been analyzing the balance between the 2 layers many have definitely noticed there have been on several occasions these 2 layers do not always move in tandem but when they lock in together in either direction they typically really lock in. Impressive chart this year to say the least this reversal was strong even for a wave 1 event from record setting levels at 60N to creating a record on the opposite end.

u60n_50_2024_merra2.pdf

[Stormchaserchuck1]

^It's one of the highest correlations I've ever done on the NOAA Physical science maps.  If you have the time, I highly recommend that people go back to 1948 (the start of their dataset) and look at all cold season 10mb events vs the 500mb pattern. What I found is spectacular!

The Stratosphere warming (+10mb geopotential height) signal translates to -NAO at different times of the year:

October: +60 days

November: +45 days

December: +30 days

January: +25 days

February: +20 days

March: +15 days

April: +10-15 days

The mean for daily composites in the allotted times was as high as a +120dm -NAO mean signal! 

For cold Stratosphere times (-10mb geopotential height), it's not the same as a warming! The effect on the surface and 500mb is immediate!

October: + 0 days

November: + 0 days

December + 0 days

January: + 0 days

February: + 0 days

March-April: + 0 days

We are still mastering science, and I expect improvements with further research, but the basic reading is already a high correlated factor, generally.  This particular one is not hitting it besides a 3-4 day period though. Not really surprising because we had so many strong/near record breaking +NAO periods in 2024. 

[snowman19]

Becoming pretty confident that we do not see an El Niño. The PMM has become severely negative (cold water off of Baja). -PMM argues very strongly against Nino development. My best guess right now is La Nada/neutral and most likely cold-neutral 

[LibertyBell]

On 4/4/2025 at 9:26 PM, Stormchaserchuck1 said:

Stratosphere warming is still going strong.. one of the strongest ones in history, actually, because it's having these +1800dm anomalies cover 3-4 weeks. I think the highest I ever saw 10mb get historically on a daily was +2900dm. 

Latest daily map

3-10 is about when it started.. last 22 days:

It will probably last for another week. 

a final warming event?

it resulted in our latest below freezing temperature (31) this morning since about 2014 when we had some accumulating snow on 4/16/2024.

 

[Stormchaserchuck1]

2 hours ago, LibertyBell said:

a final warming event?

it resulted in our latest below freezing temperature (31) this morning since about 2014 when we had some accumulating snow on 4/16/2024.

 

Yeah, got down into the 20s here. It was from -NAO, which falls within the range of time after a Stratosphere warming event, so it most likely was connected. 

[GaWx]

2 hours ago, LibertyBell said:

a final warming event?

it resulted in our latest below freezing temperature (31) this morning since about 2014 when we had some accumulating snow on 4/16/2024.

 

This looks to end up as the 2nd earliest major SSW that also ends up as a FW since records began in 1958. This one reversed ~3/9/25 and has remained reversed since. The earliest on record is Mar 5th (2016). The 3rd earliest is Mar 11th (1984).

[Stormchaserchuck1]

More cool April, per the after effects of March 10 - Apr 10 Stratosphere warming

The cold season correlation is about -0.2 in the East +time

[PhiEaglesfan712]

MEI for FM 2025 was -0.7

[Stormchaserchuck1]

10mb warming still going strong on April 10th... making it 32 straight days! (1st day was March 10th)

[LibertyBell]

On 4/10/2025 at 6:14 PM, Stormchaserchuck1 said:

More cool April, per the after effects of March 10 - Apr 10 Stratosphere warming

The cold season correlation is about -0.2 in the East +time

cool April will come to an end beginning this weekend.

[Stormchaserchuck1]

5 hours ago, LibertyBell said:

cool April will come to an end beginning this weekend.

Yeah, overall the SSW underperformed a bit wrt to below average temps in the East and Europe. 

[snowman19]

FWIW, this is what the Copernicus is showing for this summer (continuation and strengthening of the marine heatwave in the NW Pacific/-PDO, cold-neutral ENSO, -PMM) also, a developing, descending -QBO:

[Stormchaserchuck1]

A lot of models are showing above average temps just about everywhere in the CONUS for the Summer.. they had 80% of the country above average for DJF though, and it ended up being 70% below average.. not a perfect science, but it seems like a lot is favoring a hotter than average Summer. SW, US heat ridge is expected to really pick up in a few weeks, and that's usually a leading indictor to weather further east +months time. 

[snowman19]

1 hour ago, Stormchaserchuck1 said:

A lot of models are showing above average temps just about everywhere in the CONUS for the Summer.. they had 80% of the country above average for DJF though, and it ended up being 70% below average.. not a perfect science, but it seems like a lot is favoring a hotter than average Summer. SW, US heat ridge is expected to really pick up in a few weeks, and that's usually a leading indictor to weather further east +months time. 

If the Copernicus is correct (-PDO, cold-neutral ENSO), it’s probably going to be a hot summer in the east, especially coming off a La Niña (“hangover”)….

[PhiEaglesfan712]

3 hours ago, snowman19 said:

If the Copernicus is correct (-PDO, cold-neutral ENSO), it’s probably going to be a hot summer in the east, especially coming off a La Niña (“hangover”)….

2013 would be the best analog. That was a very wet summer in the east, with a much cooler than average August. It was a frontloaded warmth summer in the northeast, but a much cooler than average summer in the southeast.

[bluewave]

19 hours ago, Stormchaserchuck1 said:

Yeah, overall the SSW underperformed a bit wrt to below average temps in the East and Europe. 

This was expected due to the record lack of coupling this year. 

 

[LibertyBell]

On 4/16/2025 at 12:46 PM, Stormchaserchuck1 said:

A lot of models are showing above average temps just about everywhere in the CONUS for the Summer.. they had 80% of the country above average for DJF though, and it ended up being 70% below average.. not a perfect science, but it seems like a lot is favoring a hotter than average Summer. SW, US heat ridge is expected to really pick up in a few weeks, and that's usually a leading indictor to weather further east +months time. 

any good analogs? The type of heat you're describing sounds like 1980

[LibertyBell]

18 hours ago, PhiEaglesfan712 said:

2013 would be the best analog. That was a very wet summer in the east, with a much cooler than average August. It was a frontloaded warmth summer in the northeast, but a much cooler than average summer in the southeast.

screw wet, no one wants a wet summer, that needs to stay in the spring.

Give me a 2010 repeat

[LibertyBell]

22 hours ago, snowman19 said:

If the Copernicus is correct (-PDO, cold-neutral ENSO), it’s probably going to be a hot summer in the east, especially coming off a La Niña (“hangover”)….

as long as we dont get onshore flow and lots of rain I'm happy with a hot dry summer like 2010.

[Stormchaserchuck1]

57 minutes ago, LibertyBell said:

any good analogs? The type of heat you're describing sounds like 1980

I made a pretty good research about a strong 10mb vortex Nov-Feb, switching strongly to the opposite state in March. This year is about the most extreme example of that, so it's valid analog work. 

Analogs favor a hotter Summer. 

[Stormchaserchuck1]

6 hours ago, bluewave said:

This was expected due to the record lack of coupling this year. 

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. 

[LibertyBell]

1 hour ago, Stormchaserchuck1 said:

I made a pretty good research about a strong 10mb vortex Nov-Feb, switching strongly to the opposite state in March. This year is about the most extreme example of that, so it's valid analog work. 

Analogs favor a hotter Summer. 

Look up maps of June-September 1980, the heat began in the SW and expanded northeastward and covered the whole country except for the west coast by July 20th and stuck around until September 20th.

Large loss of life in St Louis, 1980 was to St Louis like 1995 was to Chicago.

The hottest August on record for NYC and the only August that averaged 80.0 or higher.

 

[Stormchaserchuck1]

28 minutes ago, LibertyBell said:

Look up maps of June-September 1980, the heat began in the SW and expanded northeastward and covered the whole country except for the west coast by July 20th and stuck around until September 20th.

Large loss of life in St Louis, 1980 was to St Louis like 1995 was to Chicago.

The hottest August on record for NYC and the only August that averaged 80.0 or higher.

 

You got me thinking, since '79-80 was such a big +PNA Winter. and per CPC, this was record +PNA Winter non-El Nino. So the roll forward does actually have a decent correlation with hot Summer. 

[LibertyBell]

6 minutes ago, Stormchaserchuck1 said:

You got me thinking, since '79-80 was such a big +PNA Winter. and per CPC, this was record +PNA Winter non-El Nino. So the roll forward does actually have a decent correlation with hot Summer. 

wow that would be an interesting summer to relive, the July-August couplet was the hottest on record at NYC, 62 days average temperature over 80.0 (off the top of my head I think July averaged 79.7 and August averaged 80.6) in NYC.