A winter storm is blanketing parts of the U.S., causing snowfall in parts of North Texas and thousands of flights to be canceled at Chicago’s two main airports.

In the northern half of the country near Chicago, freezing rain and high winds are expected to turn into snow later on Saturday, while some areas around North Texas saw one to three inches of snow by Saturday morning.

WREX reported that the Saturday morning storm caused the Chicago Department of Aviation to cancel 55 flights at Chicago Midway International Airport and 949 flights at Chicago O’Hare International Airport.

“This is causing some arriving flights to be delayed an average of 4 hours and 31 minutes,” the Federal Aviation Administration said in a statement.

The National Weather Service issued a winter storm watch from Friday evening through Saturday evening in the Chicago metropolitan area.

The Texas Department of Transportation is warning drivers to be on the lookout for slippery conditions, especially driving in areas where bridges may have iced over, WFAA reported.

Fat flakes covered parts of Ponder, Texas, while residents of Plano, Texas, reported seeing sleet and freezing rain.

Snow also covered rooftops and lawns in Frisco, Texas, where one resident reported seeing her first snowfall.

WFAA reported that the Dallas-Fort Worth area should expect nothing more than a dusting of snow, but expect possible flurries.