Midwest Weekly Highlights - February 22-28, 2006

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February Ends Quietly, but on the Cold Side

A change to a more persistent northwesterly flow aloft over the eastern United States the last week of February brought a cold end to February and climatological winter (December through February). Temperatures this week across the Midwest ranged from 2°F above normal in western Iowa and Missouri to 14°F below normal across northern Minnesota (Figure 1).  However, much of the region was more moderate, with temperatures ranging from near normal to about 4°F below normal.

The week was also very dry, with a substantial portion of the region receiving little measurable precipitation (Figure 2), and there was little change in the drought status across the central and southwestern Midwest (Figure 3).  The exception was northern Minnesota, extreme northern Wisconsin, and the Michigan Upper Peninsula where up to twice the normal weekly precipitation fell. Much of the precipitation in these areas fell in the form of snow as a series of weather systems raced across the northern Midwest.  Snowfall for the week exceeded 10 inches across the northern Great Lakes region (Figure 4), providing an added boost to the late winter recreation season.  Fifteen to 24 inches of snow was on the ground from northeastern Minnesota across extreme northern Wisconsin and the Michigan U.P. at the end of the month.  Most of the snow this week fell in the first three days of the period.  A strengthening low pressure system in the Dakotas on February 24 prompted a variety of winter weather advisories to be issued from the Dakotas eastward through northern lower Michigan (Figure 5).   Following the passage of this system, the weather was uneventful the remainder of the week.


SDH