The Northern Rockies have been pounded with multiple rounds of heavy snow over the past 7-10 days. Last week, the town of Jackson, WY experienced its fourth largest 2-day snowfall on records with 21.0″ over two days (and up to 50″ in 4 days in the Teton Mountains), while this past weekend Sun Valley Ski Area recorded one of it’s biggest storms in recent memory with 29.0″ in 24 hours.
The storm train continues this week as another strong Pacific system is approaching from the northwest. This morning’s water vapor satellite image depicts the moisture approaching the area (image source: NOAA).
Snow showers will be ongoing across many of the mountain areas of Idaho, Wyoming, and Montana before the main system arrives later today. Heavy snow will develop across Central Idaho late this afternoon/early evening, before spreading into Eastern Idaho, Western Wyoming, and Western Montana by early Wednesday morning.
Good upper level dynamics along with a moist SW flow should produce heavy snowfall amounts around Ketchum and Hailey, with snowfall amounts of up to one foot possible in the Wood River Valley through Thursday morning, and amounts over the higher mountain passes such as Galena Pass in the 10-20″ range.
Eastern Idaho and Western Wyoming including Jackson Hole will see its heaviest snowfall during the day Wednesday and continuing through Thursday morning with snowfall amounts projected to range from 4-8″ in the Jackson Hole Valley and 10-20″ over the mountain passes, including Teton Pass.
Over the lowlands Eastern Idaho including Pocatello and Idaho Falls, snowfall amounts look to range from 2-5″ from Wednesday through Thursday morning, but precipitation could change to rain during the day Thursday.
SW Montana will also see heavy snow from Wednesday morning through Thursday morning, with amounts projected to range from about 3-6″ in Bozeman and 8-16″ over the mountain passes.