After a rare winter storm walloped the South with record snowfall, from the swamps of Louisiana to the beaches in the Carolinas, the region faced a new threat Thursday morning of dangerously icy roads that, in some parts, may not fully melt until the weekend.

Such conditions left officials throughout much of the South echoing the same message: The effects from the storm were not over, and driving remained a hazard on untreated roads still frozen with slippery ice.

While temperatures were expected to briefly rise above freezing in parts of Louisiana, southern Alabama and Mississippi, Georgia, northern Florida and coastal communities in the Carolinas, colder nighttime temperatures would likely cause snow and ice to refreeze on roads. There is also an increased risk of black ice, the slick patches that can form unpredictably and almost invisibly because they blend in with the asphalt.

“Ice is ice, and it will present a hazard to motorists if they’re not prepared,” Richard Bann, a meteorologist with the National Weather Service, said.

The threat is worse in a region that is unaccustomed to severely cold weather, and where snow plows are not regularly well stocked.

The storm was already extremely disruptive in the region earlier this week, with scores of schools canceling classes, airports delaying or canceling flights and travel made nearly impossible. Fueled by a whirling mass of Arctic air, the storm has also killed at least 10 people in Texas, Alabama and Georgia.