2025-2026 ENSO

[snowman19]

Just now, brooklynwx99 said:

meh. I find that hard to believe given the coupled SSW and MJO progression. should get quite favorable after the 10th, not the other way around

I mean, he totally went against what the EURO weeklies and the other ensembles were showing run after run for early December and if that should actually happen, maybe he’s onto something?

[MJO812]

25 minutes ago, snowman19 said:

Paul Roundy actually expected this cold shot at the start of December based on his tropical low frequency forcing plots. He’s been saying for weeks that the SE ridge would be at its weakest in early December then get stronger post 12/10

Should be the other way around

[Maestrobjwa]

15 minutes ago, brooklynwx99 said:

meh. I find that hard to believe given the coupled SSW and MJO progression. should get quite favorable after the 10th, not the other way around

Did the SSW actually happen/still on track to happen?

[GaWx]

27 minutes ago, snowman19 said:

Paul Roundy actually expected this cold shot at the start of December based on his tropical low frequency forcing plots. He’s been saying for weeks that the SE ridge would be at its weakest in early December then get stronger post 12/10

 
 This only recently seen on the models cold shot is for the weekend after Thanksgiving. So, this is technically during the last days of Nov. Then I still expect a mainly mild first half of Dec. while the MJO crosses 7 and we wait to see what the SSWE does just afterward. Of course expectations and reality sometimes don’t match well.

[MJO812]

Euro is now cold in the long range. Big change.

[kazimirkai]

18 minutes ago, MJO812 said:

Should be the other way around

Well it's pretty normal to expect that the MJO wouldn't reach phase 8 in a la-niña situation with base easterlies, but forecasts change. Still tough to say if it'll stay there long but that seems to be the crux of the change in forecasts over the past week or so. 

[George001]

14 minutes ago, MJO812 said:

Should be the other way around

The 500mb pattern shown in Roundys post actually looks quite favorable for New England. -EPO/-NAO/-PNA with an SE ridge that does not link up with the block. It’s also worth noting that the -NAO here is more east based than south based like the past few years. 

[GaWx]

Today’s Euro Weeklies 2m temp anomalies vs prior run in E US

Dec 1-7: slightly cooler NE US but still mild overall Mid-Atlantic and especially SE/warmest week of Dec

 

Dec 8-14: NE cooled slightly from slightly AN to NN but SE ~same

 

Dec 15-21: slightly warmer SE (was NN); ~same NE

 

Dec22-28: slightly warmer but still coldest week of Dec

[MJO812]

1 hour ago, GaWx said:

Today’s Euro Weeklies 2m temp anomalies vs prior run in E US

Dec 1-7: slightly cooler NE US but still mild overall Mid-Atlantic and especially SE/warmest week of Dec

 

Dec 8-14: NE cooled slightly from slightly AN to NN but SE ~same

 

Dec 15-21: slightly warmer SE (was NN); ~same NE

 

Dec22-28: slightly warmer but still coldest week of Dec

Looks really good in December. All systems go if it holds.

[simbasad2]

1 hour ago, GaWx said:

Today’s Euro Weeklies 2m temp anomalies vs prior run in E US

Dec 1-7: slightly cooler NE US but still mild overall Mid-Atlantic and especially SE/warmest week of Dec

 

Dec 8-14: NE cooled slightly from slightly AN to NN but SE ~same

 

Dec 15-21: slightly warmer SE (was NN); ~same NE

 

Dec22-28: slightly warmer but still coldest week of Dec

If these weeklies verify then the 2nd half of December is game on for the Northeast and Mid-Atlantic in my opinion. Especially with the MJO entering phase 8 by that time

[mitchnick]

1 hour ago, MJO812 said:

Looks really good in December. All systems go if it holds.

These weekly Eps snowfall anomaly maps are from Monday fwiw.

[EasternLI]

4 hours ago, kazimirkai said:

Well it's pretty normal to expect that the MJO wouldn't reach phase 8 in a la-niña situation with base easterlies, but forecasts change. Still tough to say if it'll stay there long but that seems to be the crux of the change in forecasts over the past week or so. 

Remains to be seen if we can achieve phase 8. Still a little bit too far in the future for guidance, but this year... maybe? There's been somewhat of a notable trend on the EPS over the last couple of days now with the mjo. Incrementally amplifying the phase 7 transit through several runs. With today's 12z run the most amplified thus far. I bring up the EPS since it's been the one piece of guidance that has been the most reluctant with this event throughout. Here are yesterday's 00z run followed by the latest 12z EPS 200mb velocity potential (the ones in between follow the same trend).

00z yesterday:

 

12z today:

 

Taking a global view of this now, in the 10-15 day mean. It's a fairly clear phase 7 signature being shown now on the 5 day mean. With the suppressed phase pushing into the MC and the enhanced phase pushing into South America. Again, this signal has been growing. Not fading away, much like we are all accustomed to in recent times, as verification time approaches. 

 

 

Consistent with the slower moving mjo events, as mentioned earlier in this thread. There should be a response reflected in the 500mb pattern. Or at least more likely. So I like to check the model output against the mjo composites in times like these. Since that is most certainly not always the case. In this instance though, there do seem to be at least several similarities between the phase 7 December La Nina composite. When compared with the 12z EPS forecast at day 15. Which, to me, suggests it is indeed being effective. At least in the model.  What happens from here? I'm beginning to think it might be interesting to find out.

 

 

[40/70 Benchmark]

6 hours ago, George001 said:

The 500mb pattern shown in Roundys post actually looks quite favorable for New England. -EPO/-NAO/-PNA with an SE ridge that does not link up with the block. It’s also worth noting that the -NAO here is more east based than south based like the past few years. 

I love the December pattern for us....mid Atlantic not as much.

[bncho]

4 minutes ago, 40/70 Benchmark said:

I love the December pattern for us....mid Atlantic not as much.

i don't think the mid-atlantic should expect to see anything until december 15. after that things look more favorable and it might be game on for us

[stadiumwave]

8 hours ago, GaWx said:

 
 This only recently seen on the models cold shot is for the weekend after Thanksgiving. So, this is technically during the last days of Nov. Then I still expect a mainly mild first half of Dec. while the MJO crosses 7 and we wait to see what the SSWE does just afterward. Of course expectations and reality sometimes don’t match well.

 

Phase 7 in DEC is usually a decent phase though??

[MJO812]

Gfs has gotten colder for Thanksgiving 

[GaWx]

50 minutes ago, stadiumwave said:

 

Phase 7 in DEC is usually a decent phase though??

 I’d call it average. At Baltimore since 1974 during 3+ day long phase 7 periods during Dec (32 of them adding to 185 days), they’ve averaged 0.5 F warmer than normal with the coolest tending to be somewhat weak and warmest tending to be somewhat strong though with much variation. The range during La Niña has been as cold as 11 BN (12/16-20/2010), 7 BN (12/9-10/1995), and 5 BN (12/9-11/2017) to as warm as 13 AN (12/28-31/2024) and 7 AN (12/19-31/2021).

 Breakdown of these 13 phase 7 periods during La Niña in Dec:

1 MB, 4 B, 2 N, 5A, 1 MA

[MJO812]

5 minutes ago, MJO812 said:

Gfs has gotten colder for Thanksgiving 

Same as black Friday.  Cold air comes in quicker. 

[BlizzardWx]

https://x.com/webberweather/status/1990921925745410375

Webb says the tropical troposphere is already El Nino like. I wonder if this is playing into the strengthening trends for the MJO mentioned above.