Wednesday afternoon and evening bring the first significant thunderstorm outbreak of 2015, and the first real risk for severe storms. Heavy downpours, hail and high winds are quite possible from the Twin Cities south.

Synopsis: The weather set up

A “thermal ridge” pushed a wedge of 70 and 80 degree temperatures into the Dakotas Tuesday. Temperatures hit the low 80s in Pierre, Winner and Phillip, South Dakota Tuesday afternoon.

University of Illinois

Warm southerly breezes blow in warm and slightly moist air ahead of an advancing cold front Wednesday. As the front reaches southern Minnesota just at “peak heating” time, look for a rapidly developing line of showers and thunderstorms to blossom.

National Oceanic and Atmospheric Administration

Here’s a closer look at the probable timing according to the National Oceanic and Atmospheric Administration’s Global Forecast System model.

Bottom line? Stay alert for thunderstorms developing around mid-afternoon into the evening that could produce strong winds and some hail. There is a small risk a few of the storms could reach severe limits in the Twin Cities, and more significant risk in southern Minnesota.

Stay “situationally aware” for storms and possible watches and warnings Wednesday afternoon and evening.

Welcome rainfall

The good news? The storms should be widespread and slow moving enough enough to bring some valuable rainfall to southern Minnesota. If storms develop right over the metro, rainfall totals of .50 to 1 inch may fall from the metro south.

Some 2 inch totals could fall along the Interstate 90 corridor near Rochester and Albert Lea.

NOAA via