Above-Normal Temperatures for Midwest, Except Missouri

Above-normal temperatures returned to much of the Midwest this week (Figure 1). Minnesota had the largest temperature departures as the entire state averaged 2.8°F above normal. Wabasha County, Minnesota recorded an average maximum temperature of 87°F, average minimum temperature of 57°F, and an average temperature of 72.1°F (6.2°F above normal). Ohio averaged 2.7°F above normal. Illinois, Indiana, Iowa, Kentucky, Michigan, and Wisconsin all averaged between 0.8-2°F above normal for the week. The only state to average below-normal temperatures was Missouri, which ran 0.8°F below normal. Portions of the Ohio River Valley recorded maxiumu temperatures 1-5°F below normal, with the largest departures occurring in east-central Missouri and western Illinois (Figure 2). Maximum temperatures were 1-4°F above normal in western Iowa, Minnesota, and Wisconsin. Locations in southwestern Minnesota had high temperatures 6°F above normal for the week. Minimum temperatures were above normal for most of the region, with largest departures occurring in Indiana, Ohio, and eastern Kentucky (Figure 3).

Variable Precipitation Continues

The heaviest precipitation fell along the Ohio River, especially in southeastern Indiana, southwest Ohio, and northern Kentucky (Figure 4). In this region, precipitation totals ranged from 1.5 to nearly 6 inches, which was in excess of 200 percent of normal (Figure 5). Butler County, located in southwest Ohio, measured 5.85 inches of total precipitation, where 3.6 inches fell on September 9. To the north and west of this line, many locations missed out on the rain and received less than 50 percent of normal precipitaiton. In fact, areas in Indiana, Michigan, Wisconsin, Minnesota, Iowa, and Missouri missed out on any measurable precipitation this week. As expected, river and stream gauges recorded above normal streamflow values in the region that received the most precipitation (Figure 6). Gauges in northwestern Indiana, central Illinois, northern Missouri, southern Iowa, and eastern Michigan showed below-normal streamflow values. There were 46 daily precipitation records broken or tied this week, with most occurring in the Ohio River Valley (Figure 7). Fox 59, in Indianapolis, Indiana, reported that flash flooding in southern Indiana claimed a life as their home was washed away. WLFI TV-18 in West Lafayette, Indiana, reported that the Indiana Department of Homeland Security was to visit Ohio, Jefferson, and Switzerland counties to determine the scope of the flood damage and whether to issue state disaster declarations, which could lead to pursuance of Federal Emergency Management Agency funding.

Drought Update

The September 6 US Drought Monitor brought little change from the previous week (Figure 8). Minor adjustments in Illinois were made, where the Moderate Drought (D1) in the east shrank and expanded in the west. Abnormally Dry (D0) conditions in southern Indiana were removed and northeastern Ohio was reduced in size.