UNDATED -- A hot and humid airmass will spread over the Upper Midwest today.

Highs in the mid 80s to lower 90s and dew points in the low to mid 70s will bring heat indices of 95 to 100 degrees by early afternoon.

A cold front will push east into western Minnesota this afternoon. Thunderstorms will develop rapidly along it, becoming more intense and widespread as they track east through early this evening.