The rain and thunderstorms rolling through the nation's midsection todaythreaten to have a major impact on air travel. The wet, stormy weather coulddelays planes arriving or departing in St. Louis, Little Rock, Detroit andPittsburgh.Rain has already led to delays this morning at Chicago's O'HareInternational Airport. Heavy rain and thunderstorms will continue to spreadover the city through the morning. Flight delays that ensue at the start of theday could continue to impact airline passengers in the afternoon despiteimproving conditions.

The ripple effect from delays at O'Hare may create problems at other majorairports across the nation.

Story by AccuWeather.com Senior Meteorologist Kristina Pydynowski