Southern Midwest, Cooler; Upper Midwest, Warmer

The southern Midwest recorded below normal temperatures and the upper Midwest observed above normal temperatures for the third week of August (Figure 1). Preliminary state average temperatures were 1.7°F above normal for Michigan and 0.6°F above normal for Minnesota and Wisconsin. Saint Clair County, Michigan’s average temperature was 75°F for the week, which was 3.2°F above normal. All other Midwestern states experienced below normal temperatures ranging from 0.4°F (Ohio) to 3.7°F (Missouri) below normal. Buchanan County, Missouri observed an average temperature of 69.4°F, which was 5.8°F below normal for the week. Maximum (Figure 2) and minimum (Figure 3) temperatures followed similar temperature trends (warm in north and cool in south). Maximum temperature departures appeared to have the higher impact on the below normal average temperatures. Maximum temperatures ranged from 1-5°F below normal, with isolated locations in Missouri and Kentucky in excess of 6°F below normal. In this region, there were 3 minimum and 75 maximum daily low temperature records broken or tied.

Variable Precipitation Continues

Most of the Midwest saw at least 0.5 inches of precipitation, but isolated areas in southeast Illinois, southern Indiana, central Kentucky, eastern Wisconsin and northern Michigan recorded less than 0.3 inches during the third week of August (Figure 4). Many of these locations received less than 50 percent of normal rainfall (Figure 5). Based on preliminary data, Kentucky averaged 42 percent of normal precipitation and had locations that received 27 percent of normal rainfall. Eastern Wisconsin, Climate Division 6 to be exact, was the driest where 26 percent of normal precipitaiton fell. Heavier precipitation amounts were recorded in northern Minnesota, southwestern Iowa, Missouri, central Illinois, and eastern Ohio as these locations received more than 175 percent of normal precipitation. Preliminary data indicated that Missouri had the highest state-average precipitation, where 235 percent of normal precipitaiton fell. Dent County, Missouri recorded 4.02 inches of rain, which was 3.15 inches above normal. There were 50 daily precipitation records broken or tied this week. As of August 20, streamflows in southern Iowa, central Illinois, southeastern Wisconsin, and central/northwestern Indiana, and northeastern Ohio were running below normal (Figure 6). Southeastern Wisconsin (Root River at Racine, WI) and northeastern Ohio (Mahoning River at Leavittsburg and Youngstown) had read less than fifth percentile.

Drought Monitor Update

The August 16, 2022 US Drought Monitor remained relatively unchanged on a percent area basis (Figure 7). With this release, there was some improvement to the Moderate Drought (D1) in northern Wisconsin, but also addition of D1 just to the north. The Severe Drought (D2) in southeast Missourri and southwestern Kentucky was downgraded to D1. There was additional removal of Abnormally Dry (D0) in western Indiana Abnormally Dry (D0).

Storm Reports

There were five tornado, 37 hail, and 44 wind storm reports this week that occurred on August 17-21. On August 18, hail fell in Sioux County, Iowa that was 2.50 inches in diameter (tennis ball size). Hail that was 3.0 inches in diameter was reported in Polk County, Iowa and a 65-mph wind gust was estimated in Jones County, Iowa on August 19. There were five tornado reports on August 20 in Iowa, Illinois, and Indiana, all EF-0. There was 3.0 inch diameter hail in Tazewell County, Illinois with other reports of damage to buildings. An 81-mph wind gust was recorded in Allen County, Ohio. Ohio had several reports of downed trees and powerlines, and a shed was blown onto a county road in Coshocton County, Ohio.