U.S. airlines have cancelled over 7K flights over the last two days due to snowstorms, according to data from FlightAware.

On top of a monster storm hitting cities on the East Coast such as New York City, Washington D.C. and Philadelphia  – Chicago is forecast to receive up to 12 inches of snow and Detroit could be hit with up to 6 inches.

Southwest Airlines (NYSE:LUV) and American Airlines (NASDAQ:AAL) have had the most flights cancelled today by raw numbers, while JetBlue (NASDAQ:JBLU) and Republic Airlines are running at half speed on a percentage basis.