Dangerous 'Derecho' Thunderstorms Plow Toward Chicago, Milwaukee

What's This?

Radar image of the storms heading for the Chicago area at 6:05 pm ET.

Image: RadarScope

By Andrew Freedman2014-06-30 22:04:37 UTC

A nasty line of storms has barreled across Iowa today, taking aim at Milwaukee and Madison, Wisconsin, as well as Chicago and Rockford, Illinois, during the next few hours.

See also: Freak Thunderstorm Spawns Twin Tornadoes as Severe Outbreak Hits U.S.

The storm complex is technically known as a mesoscale convective system, basically a large group of organized thunderstorms. These storms are feeding off a warm, moist air mass, and strong winds in the low and mid-levels of the atmosphere are being pulled down to the surface, making them especially dangerous.

The National Weather Service issued a rare "Particularly Dangerous Situation" severe thunderstorm watch" for areas from Chicago to South Bend, Indiana, as the storms plow eastbound. Wind gusts to 80 miles per hour or greater are possible with these storms.

If the damaging winds extend far enough, this will be considered a derecho event. Such events are capable of causing widespread power outages and tree damage.

This event is impacting one of the busiest airports in the world at Chicago's O'Hare International, where it's already resulting in a ripple effect of airport delays nationwide.

Topics: Climate, derecho, severe thunderstorm, U.S., US & World