December 2025 Forecasts and Discussions

[Typeing3]

12z GFS ensembles:

ens_image (10).png

12z ECMWF ensembles:

ens_image (11).png

12z GEM ensembles:

ens_image (12).png

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20251203204212-63b32bbd7fc93337f18f5151d76bc8e9723f5143.png

20251203204200-a2301fbf0e29db6192dfb53e84bbf7eeb1ba233d.png

[Rubus_Leucodermis]

By the way, I’ve managed to resurrect my long-dormant live upper-air observations project:

https://koosah.info/

[Bonovox]

ens_image (10).png

ens_image (11).png

ens_image (12).png

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That warm Euro OP sure is an outlier.

[AbbyJr]

Honestly, I don’t mind the models ejecting most of the cold over the water for now. We are still well over 200hrs out and it’s quite common for there to be an eastward trend as we get closer to the timeframe. Having the GOA block and polar low further west gives us more wiggle room if and when the modelled pattern trends east. Often we see everything in the sweet spot in the clown range only to shift too far east as we get closer to the event. Of course there are never any guarantees but I’m not at all concerned about things not looking perfect yet. What does concern me, however, is the potential for the GOA block to get undercut. Many of the deterministic runs suggest such an evolution. We might get briefly cold with that scenario but it wouldn’t lock in. That may not happen but it’s an unfortunate possibility.

[Catnip]

That warm Euro OP sure is an outlier.

Nito approved!

[Hawk]

Dreaded words when looking locally for snow, even in the mountains, is:
Drizzle

[Hawk]

cold onshore flow is impossible. All we seem to get is warm rains..wuta joke.
Basically all November and now the first 2 weeks of December prolly too

[PortKells]

The drunkle was a disaster but the ensembles actually look pretty good!

gfs-ens_z500a_namer_49.png

This really is right on our doorstep:

gfs-ens_T850a_namer_52.png

[Typeing3]

The drunkle was a disaster but the ensembles actually look pretty good!

gfs-ens_z500a_namer_49.png

This really is right on our doorstep:

gfs-ens_T850a_namer_52.png

Ensembles are really all that matter more than 7 days out.

Decent signs to start mid month for some zonal and NW flow here with lots of rain and mountain snows while that cold pool sets up in the north and interior.

[Bonovox]

Ensembles are really all that matter more than 7 days out.

Decent signs to start mid month for some zonal and NW flow here with lots of rain and mountain snows while that cold pool sets up in the north and interior.

Starting to think it may not even be retrogression late month after we are in that NW flow, but rather the ridge over the Aleutians slides east to set us up for something good.

[AbbyJr]

Ensembles are really all that matter more than 7 days out.

Decent signs to start mid month for some zonal and NW flow here with lots of rain and mountain snows while that cold pool sets up in the north and interior.

Cold onshore flow with an interior cold pool can lead to low elevation snows here. January 1996!

[Typeing3]

Cold onshore flow with an interior cold pool can lead to low elevation snows here. January 1996!

December 1981-January 1982!

[Storm]

That's alright too. Big Snow on this run next weekend.

gfs_mslp_pcpn_frzn_nwus_36.png

gfs_mslp_pcpn_frzn_nwus_39.png

[John]

That's alright too. Big Snow on this run next weekend.
gfs_mslp_pcpn_frzn_nwus_36.png
gfs_mslp_pcpn_frzn_nwus_39.png

Hi stormy nice to hear from ya

[AbbyJr]

December 1981-January 1982!

Even better as it was colder.