A significant snowstorm is set to unfold across the northwestern United States early this week.
“Temperatures are expected to run 20 to as much as 35 degrees Fahrenheit below normal, with record-low temperatures likely in many locations across the northern Rockies through midweek,” said AccuWeather meteorologist Kyle Elliott.
Cool air has been in place throughout and west of the Rockies for over a week now, but precipitation has been limited to mainly the highest elevations.
A powerful storm expected to dip into the interior Northwest on Monday will bring measurable snowfall to much of Montana and parts of Idaho, Wyoming and Colorado.
“Snow levels will dip to below 5,000 feet, meaning that cities such as Great Falls and Helena, Montana, may receive 6 to as much as 12 inches of snow from the storm,” said Elliott.
“Cities such as Billings, Bozeman and Missoula, Montana, are expected to remain warm enough to allow any snow to melt on contact with the ground.”
Outdoor adventurers visiting the impacted area will need to be prepared for the wintry conditions.
Yellowstone National Park and Jackson Hole, Wyoming, are popular tourist destinations that will be impacted by potentially dangerous winter weather.
“Residents in areas targeted by the snowstorm should winterize their vehicles now and make sure to have winter tires in place before venturing out early this week,” Elliott said. “Motorists traveling on Interstate 15 from the U.S./Canadian border southward through Helena and Butte, Montana, should be prepared for major delays, slippery travel and snow-packed roadways.”
While the snow will taper off on Tuesday morning, the wintry conditions will persist.
“AccuWeather RealFeel® Temperatures may plummet as low as the single digits in Great Falls, Montana, on both Monday and Tuesday night, compliments of a fresh snow pack and howling northwesterly winds,” Elliott said.
Farther north the storm was hitting southern Alberta hard with snow.
"Heavy snow will fall over the Plains and eastern slopes of the Rockies in southern Alberta into Monday night," according to AccuWeather Senior Meteorologist Alex Sosnowski.
"More than 25 cm of snow will fall in some areas and the snow can be accompanied by thunder and lightning."
Motorists should be prepared for slippery travel and delays over the Trans-Canada Highway in southern Alberta and the southeastern corner of British Columbia.
"The combination of gusty winds and heavy snowfall rates will result in poor visibility at times," Sosnowski said.
Dry weather is then expected to prevail through the remainder of the week as temperatures slowly return to normal.