Midwest Weekly Highlights - July 11-17, 2010

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Many Areas Drier Than Normal, Others See Flash Flooding

Large parts of the Midwest received less than normal precipitation in the second week of July with parts of northeast Missouri and west central Illinois receiving none (Figure 1). Where rains fell however, they were often heavy rains. Southwest Missouri and central Wisconsin had considerable areas with four times their normal rainfall and smaller areas in Indiana, Kentucky, Ohio, and Michigan did as well (Figure 2). These downpours led to flash flooding as soils, still saturated from June rains, were unable to soak up the water fast enough. More than 200 daily precipitation records were set as precipitation, though spotty, was often heavy where it did fall. Many of the records were set in Wisconsin on the 15th.
 

Temperatures Close to Normal for Most, Slightly Above Normal in Northeast

The warmest temperatures compared to normal were in the northeast part of the region. Temperatures ran 3°F to 4°F above normal in Lower Michigan and northern Ohio but were close to normal across the rest of the region (Figure 3). Parts of northern Minnesota were 1°F to 3°F below normal. Few daily temperature records were set with most being record high minimum temperatures.
 

Deadly Flash Flooding in Eastern Kentucky

On the evening of the 17th, thunderstorms dumped several inches of rain in just a few hours on Pike County, Kentucky. Rainfall exceeding 4 inches in just three and a half hours was reported at East Ridge High School with radar estimates of as much as 7 inches in the county. The resulting flash floods and mudslides are blamed for at least two deaths, dozens of injuries, and damage to more than 200 homes. 70 people were rescued from the flood waters, some from trees or roofs, as homes were washed downstream or pushed off their foundations by the water. 25,000 were left without clean drinking water and 7,000 were without power.
 

Flash Flooding in Other Locations

Throughout the week there were reports of flash flooding across the Midwest. Flash floods closed roads, washed cars into streams, flooded basements, and led to evacuations of campgrounds and hiking trails.
 

Some Drought Relief

Rains fell across many areas affected by drought. Rains for the week in Missouri, Minnesota, and Wisconsin were above normal across the areas noted in the July 13th Midwest Drought Monitor (Figure 4). On the other hand, Michigan received below normal rains in much of their drought regions.
 

River Flooding Eases

Flooding in Iowa, northern Missouri, and western Illinois generally eased during the week though parts of Iowa and along the Mississippi River still were above flood stage (Figure 5). Some Iowa rivers did swell during the week due to localized heavy rains.
 

Severe Weather Returns

July began with a welcome break from June's busy severe weather but the second week of July saw a return of more frequent severe weather (Figure 6). The western and northern states in the Midwest were hardest hit. All nine states reported severe weather with tornadoes were reported in five states and on each day except the 15th. Missouri reported twisters on the 11th and 12th, Illinois on the 12th, Wisconsin on the 14th, Iowa on the 16th, and Minnesota on the 13th, 14th, and 17th.

Among the largest hail reports were 2.00 inch hail in Fayette County, Illinois on the 11th, 2.00 inch hail in Trempealeau County, Wisconsin on the 14th, and 2.75 inch hail in Todd, Hennepin, Carver, and Wright Counties in Minnesota on the 17th, and 4.25 inch hail in Stearns County, Minnesota also on the 17th.

Widespread thunderstorm winds were blamed for downed trees and power lines, damaged crops and buildings, and vehicles blown off highways. Reports were spread across all seven days and all nine states. Numerous outdoor fairs, festivals, and concerts were cancelled due to the severe weather. Power outages affecting tens of thousands occurred across the region.
 

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