Heavy ice and snow threaten travel again in U.S. South

WINSTON-SALEM, North Carolina (Reuters) - A potentially dangerous mix of snow and ice threatened a wide swath of the U.S. South again on Tuesday, prompting hundreds of school closures from Texas to North Carolina and warnings from forecasters for people to stay off the slick roads.

"This has the potential to be a catastrophic event," said a winter storm warning advisory issued by the National Weather Service office in Peachtree City, Georgia.

Governors in Georgia, Alabama, North Carolina and Mississippi each declared a state of emergency, and officials were quick to make plans for dealing with the weather's effects after being criticized for inadequate preparation ahead of a storm two weeks ago.

The earlier rare blast of wintry weather in the region crippled Atlanta area roadways and forced more than 11,000 students in Alabama to spend the night at their schools.

Road travel was expected to be impossible in parts of Georgia on Tuesday, according to the weather service, which predicted ice accumulations of up to three quarters of an inch in some places and widespread power outages.

In extreme north Georgia, some roads, including parts of Interstate 75, were already impassable because of the snow and ice early on Tuesday, said Charlene Thrower, spokeswoman for the Georgia Emergency Management Agency.

Early on Tuesday, as many as 5 inches of snow had fallen in north Alabama, according to the National Weather Service.

A few minor crashes had been reported, but most of the state's highways remained open, Alabama Governor Robert Bentley said on Twitter.

Hundreds of schools and businesses in North and Central Texas closed or had delayed openings on Tuesday, with more than 200 reported in the Dallas-Fort Worth area alone due to icy conditions that caused traffic jams and several crashes overnight.

A winter weather advisory was in effect for the Dallas, Houston and Austin areas until Tuesday night, with forecasters warning of freezing rain later in the morning and ice accumulating on bridges and overpasses.

A Dallas firefighter died Monday night after responding to an accident on an icy road. William Scott Tanksley, 40, was killed when a car lost traction on an overpass and hit a parked car, which then hit Tanksley, pushing him off the overpass and onto a highway, media reports said.

About 1,000 U.S. flights were canceled and another 900 delayed on Tuesday, with the highest number of travel disruptions reported at Southern airports in Atlanta, Charlotte and Dallas, according to flight-tracking website FlightAware.com.

(Additional reporting by David Beasley in Atlanta; Karen Brooks and Jon Herskovitz in Austin, Texas; Verna Gates in Birmingham, Alabama; Editing by Bernadette Baum)