The storm train arrived this past weekend in the Pacific NW and it will continue to push into the Northern Rockies going into the upcoming weekend. There will be several waves coming on shore with the first on Wednesday, then Thursday, and another on Friday. Is will begin snowing overnight into Idaho and then Montana and Wyoming going into the day on Wednesday. Winter storm warnings have been posted for Jackson Hole where 1-2 feet are expected to fall by Thursday evening.
Sun Valley and Big Sky will be getting in on the some of the actions as well. Big Sky it looks like the snow will come more in inches with 6-12 inches and 8-16 inches at Sun Valley. There is more snow on the way for Thursday night through Friday night as Jackson could pick up another 6-12 inches bringing 3 day totals to 2-3 feet. Sun Valley could pick up 5-10 more inches bringing 3 day totals to 1-2 feet and Big Sky 3-6 inches bringing 3 day totals to 9-18 inches.
Salt Lake and Steamboat will be in the Southern fringe and it looks like they will only pick up a dusting at best. The storm track looks like it may shift a bit further North next weekend keeping the snows into Northern Idaho and Montana with a weaker storm for Sunday and next Tuesday. Here is the total precip map through next Tuesday.
The second half of next week and beyond the forecast models have been flip flopping. The question is will the strengthening jetstream continue to push further South and continue to bring storms into the West Coast and then into the Rockies, or will the trough dig again North of Hawaii sending the ridge up the West coast. Scenario A means more snow but a bit further South into Utah and Colorado. Scenario B means we go back to the pattern of the storms dropping down the Rockies from Canada. This is a colder buy drier pattern for the storms, but they make it all the way down to Colorado.
Right now I would lean towards scenario B as it comes from the European forecast model which has had a better handle on the long-range pattern changes. For now the pattern stay active and snowy for the Northern Rockies for the next week. We will take a new look at the secon week of January next week. BA