JACKSON, Wyo. – A powerful storm system loaded with Pacific moisture will impact Teton County on Friday and Saturday with heavy snow and strong winds for both the mountains and the valley. However, the valley will see a changeover to a rain/snow mix on Saturday afternoon.
A Winter Storm Warning is currently in effect for the Teton and Gros Ventre Mountains from 6 p.m. Friday until 9 p.m. Saturday. A Winter Storm Watch is in effect for the Jackson Hole Valley over the same time period. The valley will eventually be upgraded to either a warning or an advisory depending on the expected severity according to the National Weather Service in Riverton.
Snow will begin as early as midday Friday before picking up in the afternoon with heavy snow then expected from Friday evening through Saturday morning. Snow will continue throughout the day on Saturday across the Tetons, while warmer air arriving will result in precipitation mixing with or changing over to rain in the valley.
Late Saturday afternoon, a cold front will arrive with rain changing back to snow in the valley for a relatively short period before tapering off later Saturday evening.
The Tetons will see a total of 10-20 inches of snow from Friday afternoon through Saturday night. The snow will start out dry and powdery during the day on Friday but will become heavy and wet later Friday night and Saturday.
The Jackson Hole Valley will pick up 2-5 inches of snow (isolated higher amounts possible along the West Bank and north of the airport) through Saturday morning before mixing with or changing to rain with melting occurring during the day Saturday. Another inch or so of new snow is possible in the valley on Saturday evening after the cold front moves through.
Travel conditions will deteriorate over Teton Pass on Friday afternoon and evening, then will become extremely difficult throughout the day on Saturday due to the combination of heavy snow, strong winds, and poor visibility. Winds will gust up to 30 mph in the valley on Saturday and up to 50 mph over the pass, with even higher gusts expected above 9,000 feet.
Conditions will dry out briefly on Sunday in between storms, but another active period of weather is then expected from Sunday night through Wednesday with heavy snow possible in the Tetons, while the valley could see alternating periods of snow and rain.
Alan Smith, Meteorologist
