The Heat Abates

The second week of August was a sharp contrast to the previous five to six weeks of summer. Severe thunderstorms on August 13th marred an otherwise quiet week across the Midwest.

A series of cold fronts brought cooler and drier air to the region this week. Temperatures across the Midwest were near to below normal, and ranged 2°F to 3°F below normal across Iowa to near normal elsewhere (Figure 1). There were just a handful of temperature records scattered across the region this week.

Rainfall was heavy across southwestern Missouri and across northern Indiana, Ohio, and Lower Michigan (Figure 2). Precipitation across southwestern Missouri was 200 to nearly 400 percent of normal, and 150 to 300 percent of normal in the northeastern portion of the region. A large portion of the central Midwest, oriented from Minnesota southeast through Illinois and into western Kentucky continued to miss out on the rain. Showers and thunderstorms occurred in this band, but amounts were light and coverage was minimal. This is a pattern that has persisted since early July. A band from southeastern Iowa to western Indiana has received less than 50 percent of normal rainfall since July 1st (Figure 3). The continuation of dry weather along with the heat in July has been taking a toll on crops. Only 50 percent of the corn and soybean crop is estimated to be in good to excellent condition in Illinois as of August 14th. The August 9th U.S. Drought Monitor depicts Moderate drought conditions across central Illinois and Indiana, and Severe drought in the southwestern corner of Missouri (Figure 4).

Severe Weather

Severe storms occurred in all nine states this week, but the severe weather was concentrated in Illinois, Indiana, western Ohio, and central Kentucky (Figure 5). Most of the severe reports were for winds and hail, although one tornado was reported in southern Wisconsin. A weak tornado was observed over Lake Monona near Madison, WI (Dane County) on August 8th. On August 13th severe thunderstorms rolled through Illinois and Indiana. Thunderstorms winds toppled a stage at the Indiana State Fairgrounds in Indianapolis (Marion County)where fans had gathered for a concert. Five people were killed and more than 40 people were injured when the staged collapsed on workers and fans near the stage.

Strong sustained northwest winds behind the cold front that passed through the region on August 9th generated large waves and rip currents along the Lake Michigan shoreline. Two Michigan men lost their lives near Saugatuck Dunes State Park in Michigan (Allegan County) when they were caught in a rip current and pulled out into the lake. Waves were estimated to be six feet at the time. One man drowned near Gary, IN (Lake County) on August 10th after being caught in a rip current.