WASHINGTON (AP) - Meteorologists are warning that a gigantic line of powerful thunderstorms is likely to threaten one in five Americans.
The storm system is forecast to rumble Wednesday from Iowa to Maryland. It may be accompanied by gusty wind, heavy rainfall, and large hail.
The continuous line of storms might even spawn an unusual weather event called a derecho. That's a massive storm of strong straight-line winds spanning at least 240 miles. A historic derecho in late-June and early-July of last year killed 13 people and knocked out power to 4 million residents.
Bill Bunting, operations chief at the National Weather Service's Storm Prediction Center, says Wednesday's storms are likely to cause power outages, to be followed by oppressive heat. Major cities at risk include Chicago, Indianapolis, Cincinnati, Detroit, Baltimore, Washington, Milwaukee, Pittsburgh, Columbus, Ohio, and Louisville, Ky.