DFW Airport ranked No. 1 on FlightAware's MiseryMap on Wednesday afternoon with the most cancellations and delays in the U.S.

The Federal Aviation Administration said American Airlines requested a ground stop for all of its flights for one hour early Tuesday, Dec. 24 due to a “vendor technological issue.” On top of that, thunderstorms are expected to roll in before noon. The Fort Worth area is already under a flash flood warning until 11:30 a.m.

While Americans on the east coast brace for snow, on the west coast some are facing flooding and high surf warnings.