August 11-17, 2021
Warm Along the Edges
Average temperatures were 1-6°F above normal in Minnesota, Michigan, Missouri, and the Ohio River Valley but near normal in the central Midwest across Iowa, Wisconsin, and much of Illinois and northern Indiana (Figure 1). Koochiching County, Minnesota, recorded an average temperature of 70.6°F, which was 6.7°F above normal for the week. The warmest departures in maximum temperature were confined to the upper Midwest, with near normal maximum temperatures across the lower Midwest (Figure 2). Maximum temperatures ranged from 2-9°F above normal in Minnesota. Isolated locations in northeast Missouri, northern Indiana, southern Illinois, southern Missouri, and Kentucky observed below normal maximum temperatures. Minimum temperatures were up to 8°F above normal across the Ohio River Valley (Figure 3). Minimum temperatures in Iowa, southeastern Minnesota, and Wisconsin were 1-5°F below normal for the week.
Wet in the East, Dry in the West
Precipitation across the Midwest was above normal in the far eastern portion of the region and far below normal in the west (Figure 4). Many areas in Illinois, Michigan, Ohio, and Kentucky received in excess of 175 percent of normal. Total precipitation was 0-0.1 inches for much of Iowa and Minnesota, which contributed to an expansion in D3-Extreme Drought conditions (Figure 5). Over 2 inches fell in eastern Michigan, eastern Ohio, and Eastern Kentucky with much of the remainder of the Midwest seeing between 0.5-1.5 inches of precipitation (Figure 6).
Severe Weather Continues
The active severe weather pattern that started last week continued into the first portion of this week. The most active days were August 10-12, with severe wind the primary hazard. Over 350 severe wind reports occurred this week, largely affecting Michigan and Ohio in addition to Illinois, Indiana, and Wisconsin (Figure 7),(Figure 8), (Figure 9) . There was one fatality on August 11 in Winnebago County in northern Illinois when high winds downed a tree on a mobile home. Additionally on August 11, there were 10 tornado reports rated weaker than EF-1 across Iowa, Michigan, Ohio, and Wisconsin. On August 12, Gibson City, Illinois, received nearly 10 inches of rain in just 6 hours, which led to widespread flooding throughout the community (Figure 10).