Tropical Storm Cristobal could soon renew its strength by uniting with another storm system coming from the west to form one giant cyclone, forecasters say.
After drenching much of the South, forecasters now expect the remnants of Cristobal to bring fierce winds, heavy rain and thunderstorms to much of the Midwest by Tuesday.
A very strong storm system sweeping out from the Rocky Mountains is expected to meld with Cristobal in the next couple of days, said Greg Carbin, who oversees forecasts at the Weather Prediction Center in College Park, Maryland.
"The two will eventually merge into a large cyclone," Carbin said. "It's a pretty fascinating interaction we'll see over the next couple of days."
Wind gusts of up to 45 mph (72 kph) are expected in Chicago