Truckers will probably have to chain up Friday as a late-season storm dumps heavy snow in the northern Rockies.
The storm will begin Thursday night, possibly as a mix of rain and snow, turning to all snow Friday as temperatures drop.
The National Weather Service has issued a winter storm warning for parts of western Montana, including the Butte, Helena and Great Falls areas. By the time the storm fades late Friday afternoon, places above 5,000 feet in the warning areas will see 6 to 12 inches of total snow. Some spots in the Crazy Mountains could see up to 15 inches.
Alex Lukinbeal, a meteorologist with the NWS office in Missoula, Montana, told FreightWaves that a late-April snowstorm of this magnitude may be more common that some people think.
“Snowstorms in the northern Rockies this time of year do happen, at least once every season,” Lukinbeal said. “It does snow into May in southwest Montana, especially when we start looking above 5,000 feet.”
Lukinbeal added that some peaks in western Montana have been hit with double-digit snow totals as late as the second or third week in May, but this only happens about once every five to 10 years.
During Friday’s storm, drivers will run into the roughest weather over mountain passes along the Interstate 90 and U.S. Highway 12 corridors. Lukinbeal said Homestake Pass, about 10 miles southeast of Butte, may end up being the worst spot.
“They’re going to be seeing 8 to 12 inches and that road has some pretty nasty grades on it,” Lukinbeal explained.
The snow will be heavy and wet, so isolated power outages may occur due to snow loading. Wind gusts will reach 35 mph in some spots, which could also lead to power outages as well as brief whiteout conditions.
Other locations like Bozeman, Dillon, Heart Butte and Browning could see 3 to 7 inches of snow and the NWS has placed these areas under winter weather advisories.
Major lanes of concern
- Interstate 15 from Great Falls to the Montana-Idaho border.
- Interstate 90 from Missoula to Bozeman.
- U.S. Highway 2 in Montana from Summit to Browning.
- U.S. Highway 12 in Montana from Martinsdale to the Montana-Idaho border.