Midwest Weekly Highlights - June 1-9, 2006

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Dry Start to June

A persistent upper air pattern over the eastern half of the country resulted in a generally dry start to climatological summer (June through August). Most of the Midwest was dominated by northwesterly flow aloft as a trough remained anchored over the eastern U.S. and a strong ridge of high pressure held fast over the Rockies (Figure 1). This upper level pattern resulted in warmer than normal temperatures across the western half of the region, where temperatures reached as much as 7°F above normal in northwestern Iowa and southwestern Minnesota (Figure 2). In the eastern half of the region, temperatures were near to below normal, falling 1°F to 3°F below normal across southern Indiana, Ohio, and much of Kentucky. Rainfall was near to above normal in a band from northeastern Missouri to southern Illinois and then through Indiana and Ohio (Figure 3). Much of the region, however, was dry this week with significant areas receiving less than 25 percent of the normal weekly rainfall (Figure 4). The portions of Missouri and Iowa still in moderate drought according to the U.S. Drought Monitor missed out on much of the rain that fell this week (Figure 5).

 
Scattered Severe Weather

The upper level pattern favored frequent cold front passages in the Midwest.  As the month begin a cold front was draped from northeastern Ohio to central Indiana, southern Illinois, and southern Missouri.  An area of low pressure moving along this front brought showers and thunderstorms to the southern Midwest on  June 1-2.  There were a few severe storms scattered across the Midwest, with hail and gusty winds the primary threat.  The very cold air aloft led to the development of a few cold air funnels. Scattered thunderstorms continued across the central Midwest on June 3, and a few severe storms were reported in Iowa, Illinois, Michigan, and Ohio.

Severe weather was more widespread on June 5-6 as another cold front moved through the Midwest. The first round of severe weather on June 5 was confined to western and central Minnesota and extreme western Missouri (Figure 6). Winds were measured 65 mph near Morrison, MN, and hail estimated at 2.00 inches near Boyd, MN (Lac Qui Parle County) caused vehicle and siding damage as well as significant damage to crops in the area. The cold front, and thus the focus of severe weather, moved into Wisconsin and Iowa on June 6 (Figure 7). Tornadoes touched down in Iowa and Wisconsin.  Emergency management officials reported that tornadoes occurred from southeast of the Wisconsin Dells to the town of Portage (Columbia County). Two dozen homes suffered significant damage south of Portage, and two tractor trailers were overturned. Fortunately, no serious injuries resulted from the storms. 

On June 7 severe storms formed ahead of the cold front from eastern Ohio through southern Indiana into western Kentucky. One tornado touched down northeast of Seymour, IN (Jennings County), causing two injuries and damaging several homes. Storms diminished on June 8, with only a few reports of severe hail (>= 0.75 inch) in northern Ohio and eastern lower Michigan. On June 9 another cold front was sagging south into the central Midwest, setting the stage for unseasonably cool weather across the upper Midwest.

SDH