More than 20 million people in the Northern Plains and Upper Midwest are under threat from relentless storms this week, with a significant risk of flash flooding due to already saturated soils and abundant moisture. The region has experienced above-average heat, contributing to a favorable environment for severe weather and heavy rainfall.
Multiple disturbances are moving through the region, exacerbating the risk of flash floods. Overnight Monday into Tuesday, wind gusts exceeding 75 mph were reported in South Dakota as a line of storms moved through. This follows severe storms on Monday that produced at least six preliminary tornado reports in northern Minnesota, where emergency shelters were opened in Detroit Lakes for displaced residents. Communities in Walworth County, Wisconsin, including Lake Geneva, were still cleaning up storm damage from July 3.
A stalled front stretching from Nebraska through Minnesota and Wisconsin is serving as a focal point for storm development. The FOX Forecast Center indicates a Level 2 out of 5 severe storm threat for damaging wind gusts along a cold front moving through the Midwest. There is also a possibility of isolated tornadoes developing in Wisconsin.
The repetitive and slow-moving nature of these storms is escalating the flash flood potential, with individual thunderstorm cells expected to pass over the same areas repeatedly. NOAA's Weather Prediction Center (WPC) has issued a Level 2 out of 4 flash flood threat through Wednesday for parts of Wisconsin, Iowa, Nebraska, and northern Kansas. Widespread rainfall totals of 1 to 2 inches are anticipated by Thursday across areas including Minneapolis, Duluth, and Marquette, Michigan, with isolated pockets potentially exceeding 3 inches. Many of these areas have already seen above-average precipitation this year, increasing their vulnerability to flooding.