Thunderstorms will unleash torrential, potentially flooding, downpours overthe northern Plains and the upper Mississippi Valley through Friday.The axis for a corridor most likely to get heavy rain will reach from centraland southern South Dakota east to northern Wisconsin and the Upper Peninsula ofMichigan. Minneapolis-St. Paul and Sioux Falls, S.D., will in the area at riskfor excessive rainfall.

Highest rainfall will be 2 to perhaps 4 inches, or enough to trigger flashflooding.

Unsettled weather continuing during the weekend could lead to more heavylocally heavy rain in the Upper Midwest.

Story by AccuWeather.com Senior Meteorologist Jim Andrews.