People from the northern and central Rockies in the United States are likely to face a major snowstorm that may hinder travel during the first part of next week.
While this will not be the first snowfall of the season for some areas in the region, it may pose the most impacts.
Progressively cooler, then colder air will invade the Northwest into next week.
The snowstorm will be preceded by intermittent snow over the high country from the Cascades to the northern Rockies this weekend, according to AccuWeather Senior Meteorologist Brett Anderson.
"On Sunday, there may be a few snowflakes mixed in over the passes of the northern Cascades, but no real travel problems [are anticipated] there," Anderson said.
"The big snowstorm will evolve Sunday night and Monday over the northern Rockies and just north of the Canada border of Montana," Anderson said.
Snow will break out farther south over part of the central Rockies on Monday and Tuesday.
Snowfall will range from a few inches to a couple of feet from central and western Montana to western and southern Wyoming, northwestern Colorado and part of eastern Utah. Heavy snow will also fall on southwestern Saskatchewan and southern Alberta.
"As colder air invades the region during the storm, snow levels will fall," Anderson said.
The heavy snow will not be restricted to just the mountains in this area. Some of the heaviest snow will fall on the High Plains and foothills of Montana.
Motorists should be prepared for slushy conditions and poor visibility along portions of interstates 15, 90 and 94 in Montana, as well as I-25 and I-80 in Wyoming and I-70 in northwestern Colorado. Travel along U.S. routes 2 in Montana and the Trans-Canada Highway in Saskatchewan and Alberta could be slippery in some areas.
Snow is likely to remain northwest of Denver and just east of Salt Lake City. The snowstorm will focus south of Calgary, Alberta, and west of Regina, Saskatchewan.
"The storm will poise a threat to visitors in Glacier and Yellowstone national parks," Anderson said.
Hikers and campers in the region will be at risk for becoming stranded in deep snow, gusty winds and plunging temperatures. In the snowiest locations over the high country, temperatures will dip into the teens and lower 20s F.
At the height of the storm on Monday, AccuWeather RealFeel® temperatures will plummet to the single digits and teens over the high country and to the teens and 20s over the Montana plains.
On a positive note, as the heavy snowfall melts following the storm, much-needed moisture will seep into the ground to ease moderate to exceptional drought conditions.
Since the heavy snow will avoid the major hubs of Denver, Salt Lake City, Seattle and Calgary, major national airline delays are unlikely.
However, the storm will affect the small regional hubs, such as Missoula and Great Falls, Montana. Airline passengers heading to or from these areas should anticipate delays.