Winter 2025-26

[frd]

Snowcover and cold both become established in Canada by early December. This should help as the cold gradually pushes South with time.  

 

[Eskimo Joe]

20 minutes ago, GaWx said:

 The 6 coldest La Niña to neutral ENSO Decembers in the E US as a whole since 1974 have been 1983, 1985, 1989, 2000, 2005, and 2010:

 

 Here are the respective Dec MJOs:

1983: mainly inside COD or just outside/no strong

1985: almost all inside COD

 

1989: most of 8/1 just outside COD or inside it/no strong

 

2000:almost all just outside or inside COD

 

2005: all inside COD

 

2010: all just outside or in COD

 

 What do these 6 have in common regarding the MJO? No strong and most days just outside to inside COD. 
 
 Below are the extended progs that have the Dec 1-21 MJO: look how strong they are, especially GEFS but even the Euro is solid compared to the six cold Decembers posted. My concern is that the MJO amplitude will be too strong, based on history, to allow for a widespread intense cold dominated E US in Dec. Thus, I’m hoping the progs remain going into 8, but weaken. My hypothesis as to why strong MJO has had a tendency (though not always, of course) to not be as cold as weaker MJO is because the higher amp may tend to bring up too much warmth from the tropics, where the MJO is measured:

 
 

Any opinions?

 

[frd]

18 minutes ago, Eskimo Joe said:

 

I'm not even sure if it's wise to look at outcomes that far back.  

[Terpeast]

27 minutes ago, Eskimo Joe said:

 

No real opinion on past MJO results, but that little loop right in 7 before 8 tells me that there might be a brief period of split forcing - one in 7/8 and the other in 3/4. That split forcing in 3/4 should get suppressed quickly and we get fully into 8.