Some flights in South Florida were delayed or cancelled because of winter weather headed for the Southeast.
At Fort Lauderdale-Hollywood International, 33 flights were cancelled and 34 were delayed. Some fights have delays of up to 45 minutes.
Destinations affected by the flight changes include: Port Au Prince, Atlanta, New Orleans, Houseton, Raleigh Durham and Charlotte.
At Miami International Airprt, four flights were delayed and 51 flights were cancelled.
A winter weather expert said the South was in for weather "that many parts have not seen in years." The National Weather Service issued winter storm alerts all the way from central Texas eastward through the Gulf Coast into Georgia, the Carolinas and far southeast Virginia.
School systems from Texas to Florida announced a day ahead of time that they would close Tuesday as the frigid weather system headed toward them.
It was too early to say just how much snow could fall overnight and into Tuesday, but forecasters were warning that if all of the precipitation falls as snow -- instead of sleet -- more than 6 inches was possible. Meanwhile, the Great Lakes faced wind chills that approached 50 degrees below zero.