Small storm later Wednesday and another monster for Friday
Monday, December 12, 2016
While a storm in the Gulf of Alaska spins in place early this week, some energy moving around the west side of a large eastward moving vortex in south central Canada will keep light snow showers over the Steamboat Springs area overnight.
Tuesday should be precipitation-free before the Gulf of Alaska storm begins moving towards the West Coast. Some energy ejecting from the storm will bring a warm front through the Intermountain West on Wednesday, beginning snow showers by Wednesday afternoon and continuing overnight. The last forecast wrongly minimized the snow amounts from this type of event, and with that in mind I expect 4-8” of dense snowfall by the Thursday morning report.
Temperatures will continue to warm on Thursday as the Gulf of Alaska storm approaches the West Coast, with a large piece of energy crossing central California on Thursday followed by the main storm on Friday. This first piece of energy will carry a lot of Pacific moisture and wind, and begin moderate to sometimes heavy precipitation by Thursday night, with a rain/snow mix possible at the lower elevations.
Concurrently, a large mass of arctic air once again makes its way south across western Canada and partially phases with the main part of the Gulf of Alaska storm, eventually beginning another battle between the airmasses from the Pacific and arctic. The arctic front is expected through the region later on Friday (though timing at this point is uncertain) increasing snowfall rates even further as the snow becomes lighter and fluffier and travel becomes difficult or impossible for a time, before snows end on Saturday.
There are a lot of moving pieces that will likely change in future forecasts, but I expect another round of very significant accumulations possible by Saturday morning, followed by dry and cold temperatures through the rest of the weekend and lasting into early next week.