April Snow Cover
April 17, 2001
The snow cover extent in North America this April is fairly close to the long term average. Most of the snow in North America has retreated northward from the US border, but as is typical at this time of year, snow still remains in mountainous areas of the western US, in northern New England and in the northern plains. The snow cover in the northern plains, when it melts, may contribute to further flooding of the Red River of the North. The snow free area to the east or lee of the Rocky Mountains in the Alberta and Saskatchewan provinces of Canada is a common feature in late winter and early spring. Warm chinook winds, winds moving down the lee slopes of the Rocky Mountains, can cause large areas of snow to melt or sublimate during a period of only a few hours. Note that all of the large water bodies in Canada are still frozen solid. With cold weather forecast in the eastern US this week, the snow cover area may temporarily increase.