Thursday, February 2, 2017
A very complicated weather pattern has developed off the West Coast as the Bering Sea ridge, which was observed earlier in the season, directs cold air from Siberia and western Canada into the Gulf of Alaska as Pacific energy is routed underneath. The end result will be a week of snowfall, with 3-6” of new snow for the Friday morning report, 1-4” for each of the weekend morning reports and likely significant accumulations for a couple of days next week.
Some of the cold air from Siberia and western Canada has mixed with a strong storm between Hawaii and the U.S. mainland and is bringing more heavy precipitation to the Sierra Nevada coastal mountain range. Some energy has ejected out ahead of this storm and has mixed with more cool air from western Canada, bringing the currently observed snowfall to the Steamboat Springs area. Short-range models have increased snowfall from this system, bringing moderate to sometimes heavy showers from this afternoon through the evening before tapering off around midnight and leaving 3-6” for the Friday morning report.
Additional energy and cold air dropping into the Gulf of Alaska on Friday will not only force this weakening storm eastward across the Great Basin, affecting our area Friday night into Saturday, but form a new and stronger storm off the West Coast as it phases with a separate storm undercutting the Bering Sea ridge.
The Friday-Saturday storm is a bit of a wild-card due to its weakening nature, but 1-4” are possible overnight Friday for the Saturday morning report with another 1-4” during the day, to be reported on the Sunday morning report.
Sunday looks to be precipitation-free but likely not cloud-free as moisture lingers in the still moist westerly flow.
Pacific energy undercutting the Bering Sea ridge is forecast to strengthen early in the work week and carry the new storm eastward. Waves of energy in the Pacific jet will interact with cool air moving southward from western Canada, likely bringing a long-duration snow event to Colorado starting later Monday.
Right now, models have the heaviest snows Monday night and again during the day Wednesday, with significant accumulations likely during each period, though the details are almost certain to change as we get closer to next week. Nicer weather is advertised to return near the end of the work week as a West Coast ridge translates over the area.