Hundreds of flights have been canceled in Texas and schools shuttered as frigid conditions have iced over roadways and sleet and freezing rain are forecast for some regions.

Flights into Houston and other metro airports like San Antonio were canceled Tuesday as temperatures fell into the teens in many areas.

The National Weather Service issued a winter storm warning for the Houston area and is warning mariners of gale-force winds along the Texas coast.

Police in Austin say highways in the capital are iced over and Travis County has joined other counties in launching their emergency operation centers.

About 1,600 Austin Energy customers were without power early Tuesday.

The cold front also brought snow to some parts of North Texas, where the wind chill pushed temperatures into the single digits.