Brian_in_Leavenworth

The 12Z was way better for mountain snow than the 6Z, though not as good as last nights 0Z. And that is both for Oregon and Washington.

MJVentrice @MJVentric2h The Atmospheric ENSO Index [AEI] is indicating the strongest coupling between the atmosphere and La Nina oceanic conditions we've seen in years. This coupling signature only amplifies throughout boreal Winter 2020-2021. MJVentrice

The 12Z analogs has one comparison as early December . . . 2008.

Yeah the EPS was nice, and I trust it more than the GEFS. The GEFS looks like it has 2 camps, one with ridging over us and the other with ridging in Alaska. The Alaska ridging solution seems to win out in the long run

GEFS not good so far. Wants to move the ridge right over us by hour 276

When you get to mid to late December, you don't need actual arctic air for the Western lowlands to score. Colder than normal is needed for sure though. And in the Eastern lowlands, normal temps will suffice in many areas, other areas just need slightly below normal.

Only if there are any significant differences.

Does this look like blah? Maybe not epic yet, but way more interesting than the inversions pattern we are seeing in the mid range.

MJVentrice @MJVentrice Sudden Stratospheric Warming mischief in the CFSv2 during January.

And here is the last 5 days.

Ensemble mean is very amplified, though not in an ideal place.

It also did on the pay site that I use.

FWIW the Korean model has been consistently showing the change just before mid December/

Here is the 5 day 500mb anamolies from the weeklies:

Good find. A snippet, like how they think the colder pattern locks in. BRITISH COLUMBIA A cold and stormy winter is expected to dominate across the province. While the first half of December will be rather mild, we expect a much colder pattern will develop during the second half of December and the cold pattern should continue through most of January and February. This will also bring a heightened risk for extended periods of frigid weather and heavy snow across the province, including in the Lower Mainland and Vancouver Island