Severe winter storm Sun -mon

Rockies First

Sunday into Monday, an Arctic cold front will plunge southward from the Canadian Rockies and Prairies into the northern Rockies and Plains.
Accompanied by a vigorous upper-level shortwave trough eventually closing off into an upper low over the Great Basin, snow, heavy for some, will spread into the northern Rockies, adjacent High Plains and parts of the Great Basin and Sierra Sunday and Monday.
Strong winds behind the front may lead to blizzard conditions in parts of Montana, Idaho, Wyoming and perhaps western South Dakota from late Sunday into Monday.
As you can see in our snowfall map at right, the heaviest accumulations should occur in parts of western and central Montana and the mountains of northern Wyoming. Some moderate accumulations are also expected in the Black Hills of western South Dakota.