WASHINGTON - Severe winter storm warnings were posted by the National Weather Service on Sunday for a belt of states ranging from Texas and Oklahoma in the west across the south to Georgia and the Carolinas in the east.

The National Weather Service also warned of a winter ice storm in Alabama, while the Weather Channel's website said: "Two separate but potent winter storms will bring significant snows to the Plains and Southeast through Tuesday."

Atlanta, Dallas, Birmingham and Shreveport were among cities the Weather Channel said on its website were in the potential "snow or wintry mix zone" that could see sleet or freezing rain mixing with snowfalls.

In Shreveport, power company SWEPCO warned customers to be prepared for possible outages.

"Snow, especially wet heavy snow, can cause problems for the electric system because its weight brings down trees and power lines," Malcolm Smoak, Southwestern Electric Power Company vice president, said in a statement.

"In addition, with continuing low temperatures, the snow can be a problem for several days."

In Atlanta, ABC affiliate WSB-TV reported that Georgia Power officials had put employees on standby to prepare for power outages and various airlines includingDelta and AirTran had said there could be possible flight delays and cancellations.

North Carolina's Department of Transportation warned of severe winter weather hitting the eastern part of the state starting on Monday, with accumulating snow changing to freezing rain, advising motorists "to be alert and exercise extreme caution on all roadways," driving only if absolutely necessary.