(Reuters) – The governor of North Carolina declared a state of emergency on Friday as a major winter storm already drenching the southern plains states was expected to slam the southeast with snow and sleet this weekend.

Winter Storm Diego could bring a foot of snow to mountain areas of the Carolinas, along with sleet and freezing rain that could cancel or delay flights and snarl traffic on icy roads.

“North Carolina is gearing up for a major winter storm and we’re taking all steps necessary to have the resources we need in place to respond,” Governor Roy Cooper said in a written statement announcing the state of emergency declaration.

“Snow may be beautiful but it can also be treacherous and I urge North Carolinians to take this storm seriously and get ready for it now,” Cooper said.

American Airlines issued a severe weather advisory, waiving change fees for travelers booked through Charlotte Douglas International, a major regional hub that faces the possibility of delayed or canceled flights.

Other airports that could be affected include Asheville and Raleigh-Durham International in North Carolina, Lynchburg and Roanoke in Virginia and Greenville-Spartanburg International, South Carolina.

STOCKPILING FOOD

North Carolina emergency management officials urged residents to stockpile food and water for three days, and to keep batteries on hand for flashlights and radios in case power is lost.

Unnecessary travel should be avoided, officials said.

“I’m worried. I’ve got the milk and bread in,” said Mary Susan Bendl, 58, of Charlotte, referring to the provisions she bought ahead of the storm.

Charlotte is expected to get hit with a mix of sleet and snow that could produce 1-2 inches of ice, she said. “They’re already cutting trees away from power lines. It’s really unusual to have a storm this big this early in the season.”

Diego hit the southern plains with snow, ice and freezing rain, prompting Oklahoma Governor Mary Fallin to declare a state of emergency for all 77 of that state’s counties on Thursday.

“By time we get to (Saturday) is when the snow will begin (in the Carolinas),” said Richard Bann, a meteorologist with the Weather Prediction Center in College Park, Maryland. “We’re expecting snow in the southern and central Appalachians.”

The National Weather Service issued a winter storm warning for mountain areas of the Carolinas beginning at 7 p.m. ET on Saturday and extending through noon Monday. Coastal areas could be hit with heavy flooding, beach erosion and high winds, according to the weather service.