2025-2026 ENSO

[MJO812]

9 minutes ago, FPizz said:

After the first few days, it gets better for the east like I posted above using 2013

Take the ops with a grain of salt

[Stormchaserchuck1]

23 minutes ago, stadiumwave said:

12z suites showing a big cold dump in rockies, great plains & midwest with a pattern very early DEC 2013 looking. The pattern produced some ice & snow in the MW & OV as well back in 2013.

That's a +400dm mean ridge over Alaska for a 7-day period. Not really the same as the 1 panel you posted above. We are going to get a -EPO period but it's not going to be as strong or sustain like 2013. 

[Stormchaserchuck1]

26 minutes ago, George001 said:

You absolutely could for northern areas, December 2007 is a good example. Depends on where the boundary sets up.

Alaska is a big spot. Neutral or negative H5 is going to give you a warmer pattern pretty far north. If the ridge stays over Alaska (probably unlikely) the northern areas will be cold. I'm mostly talking about Dec 6-7-> 

[leo2000]

Seems like some utter nonsense talk about a possible AO and positive NAO . A major SSW favors, negative AO and negative NAO phases. 

[Stormchaserchuck1]

3 minutes ago, leo2000 said:

Seems like some utter nonsense talk about a possible AO and positive NAO . A major SSW favors a negative AO and negative NAO phases. 

There is a lag

[Stormchaserchuck1]

Actually the 12z GEFS looks completely different from the 0z EPS over the N. Pacific. It actually has a trough in the gulf of alaska where the EPS has a ridge. EPS has been doing better so far, but it's an interesting split. I would guess the 2 models are handling the MJO differently?

[leo2000]

17 minutes ago, Stormchaserchuck1 said:

There is a lag

Yes there is, the AO looks to go positive but it's only temporary then return negative or neutral state within the next two weeks. The weeklies also keep an negative EPO which did well last winter. I also don't think we are losing a negative EPO as all forecasts have it diving deeply negative some even have it below -4 sigma. 

[MJO812]

17 minutes ago, leo2000 said:

Seems like some utter nonsense talk about a possible AO and positive NAO . A major SSW favors, negative AO and negative NAO phases. 

Exactly 

[donsutherland1]

34 minutes ago, leo2000 said:

Seems like some utter nonsense talk about a possible AO and positive NAO . A major SSW favors, negative AO and negative NAO phases. 

Several things:

1) There remains a lot of uncertainty how the stratospheric warming will propagate. Propagation could be a big factor in prolonging/strengthening or bringing back Atlantic blocking. 

2) Even as stratospheric warming often (not always) propagates favorably to build or prolong/strengthen Atlantic blocking, one should not immediately dismiss hints of evidence to the contrary. Confirmation bias is bad for forecasting.

Such evidence exists e.g., here's the AO forecast from the EPS 46-day forecast:

Although the below table talks about considering climate change-related impacts on forecasts, I highlighted the section that relates to how  and why confirmation bias skews forecasts:

A systematic forecasting framework allows one to acknowledge such evidence while avoiding rash decisions from model noise. As I don't have a crystal ball to have 100% confidence in whether or not the above AO forecast will verify, I have made a note to continue to monitor developments.

Needless to say, there is more to it than such a framework. Each scenario has clusters of outcomes (not discussed above). 

It should be noted that such frameworks don't guarantee accuracy, but they do reduce the risks that can otherwise lead to bad forecasts, especially when one is dealing with timeframes over which model skill is limited or worse.

Finally, the 11/22 12z guidance has reaffirmed the December 1-10 idea. Indeed, more than half of the 11/22 0z EPS ensembles suggested 1" or more snow in Detroit and Toronto (a good signal for measurable snow prospects from this far out). I expect those figures to hold up with the 12z cycle.