May 18-24, 2010
Midwest Weekly Highlights - May 18-24, 2010
Warm in the Upper Midwest
The upper Midwest had above normal temperatures during the week. Temperatures were . In the southern half of the region temperatures were near normal. Further to the north temperatures above normal, as much as 10°F above normal in Michigan's Upper Peninsula (Figure 1). Temperatures warmed throughout the week reaching the 80s and 90s by the end of the week (Figure 2). Daily temperature records were most common on the 24th when hundreds of record highs occurred in the Midwest.
Spotty Rain This Week
Rainfall totals were less than a tenth of an inch in the drought stricken areas of northern Wisconsin and Michigan (Figure 3). The continued dryness in this area led to further degradation and the introduction of extreme drought in Upper Michigan early in the week (Figure 4). In southern Missouri, above normal rain fell (Figure 5) where flooding was already occurring going into the week (Figure 6). Further east, above normal rain fell in Indiana, Ohio, and southern Michigan causing new flooding by the end of the week (Figure 7). Small areas of northern Minnesota received above normal rains also.
Severe Weather
A low pressure system moved into Missouri on May 20th and moved east over the next couple days (Figure 8). Tornadoes were reported in Missouri, Illinois, Kentucky and Ohio. Large hail fell in Illinois, Indiana, Kentucky, and Ohio with the largest reports of 2.50 inch hail in Knox County, Indiana on the 21st. Also on the 21st, thunderstorm winds damaged trees from Kentucky to Michigan. A barn roof was blown off in Edgar County, Illinois and another barn was damaged in St. Joseph County, Michigan.
A strong system that brought snow to the northern Rockies trailed a cold front through Minnesota later in the week (Figure 9). Minnesota reports of wind and hail extended over three days from the 22nd to the 24th. Tennis ball sized hail (2.50 inches) near Callaway, Minnesota (Becker County) was the largest among numerous 1.00+ inch reports. Wind damage in Minnesota on the 22nd and 24th was limited to trees and limbs. On the 24th hail and wind damage also occurred in Iowa, Missouri, Illinois, and Kentucky. Among the damage reports was a report of multiple barns damaged in Scott County, Missouri.
Heavy Rain Hits Various Locations
Early in the week rivers were above flood stage in Iowa, Illinois, and Missouri. Flooding eased in Iowa and northern Illinois as the week progressed but rain in southern Missouri prevented much improvement there. CoCoRaHS rain totals on the morning of the 19th were between 1.50 and 2.75 inches across a large part of Missouri (Figure 10). Heavy rain reported on the morning of the 22nd, centered on northeast Indiana with amounts of 2.50 to 4.50 inches (Figure 11), sent rivers over their banks. Flash flooding was reported in Ohio (Warren, Defiance, Adams, and Sciotto Counties) as well this week. Duluth, Minnesota (St. Louis County) recorded 3.93 inches of rain on the 23rd setting a new record for any date in May. The old record of 3.02 inches was set way back on May 22nd, 1884.
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