Winter Chill Sets In
After a very warm month of January across the Midwest, cold winter air invaded the region during the first week of February
(Figure 1). Temperatures were 2-5°F below normal across most of the region. Some areas in southwestern Missouri, northern Michigan, Minnesota and northwestern Wisconsin were near normal, however. Some of the coldest areas were in southern Wisconsin and northern Illinois, where temperatures were 6-8°F below normal. While cold throughout the week, extreme cold entered the region through the mornings of February 6 (Figure 2) and February 7
(Figure 3), where minimum temperatures in the minus teens and -20s were common. Many of the 100 daily records broken in the region (Figure 4) were in Wisconsin, northern Illinois, Iowa and Minnesota.
Snowy in the Upper Midwest
Two storm systems near the end of the week led to most of the precipitation in the Midwest during the week (Figure 5). Total precipitation amounts throughout the region totaled mostly from 0.2 to 0.75 inches, with areas in southwestern Missouri and northern Minnesota receiving less. Isolated areas in the U.P. of Michigan, southeastern Ohio and central Kentucky had up to an inch of precipitation. Most of Wisconsin and the U.P. of Michigan had more than twice the normal amount of precipitation for the period (Figure 6). Areas in Iowa, northern Illinois, northern Missouri and southern Minnesota were also slightly above normal. However, drier conditions were observed across southern Missouri and northern Minnesota where less than half the normal amount fell. Most of the Ohio River Valley was below normal.
Snowfall amounts of 4-6 inches fell in Wisconsin, Michigan, southern Iowa and northern Ohio
during the period (Figure 7). Most of this snowfall came at the end of the week. Heavy snow fell in Wisconsin through the morning of February 5 (Figure 8), while lake-effect snowfall continued through the morning of February 6
(Figure 9). Another storm then began through the morning of February 7 (Figure 10), bringing moderate snow to Iowa. Moderate to heavy snow in Iowa, Wisconsin, Michigan, Ohio, eastern Kentucky and northern Missouri represented more than twice the normal amount of snow for the week