The rain and thunderstorms rolling through the nation's midsection today threaten to have a major impact on air travel. The wet, stormy weather could delays planes arriving or departing in St. Louis, Little Rock, Detroit and Pittsburgh.

Rain has already led to delays this morning at Chicago's O'Hare International Airport. Heavy rain and thunderstorms will continue to spread over the city through the morning. Flight delays that ensue at the start of the day could continue to impact airline passengers in the afternoon despite improving conditions.

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

Story by AccuWeather.com Senior Meteorologist Kristina Pydynowski