At least 11 deaths across the region were blamed on the treacherous weather Wednesday, including three people who were killed when an ambulance careened off an icy Texas road and caught fire.
Nearly 3,300 airline flights nationwide were cancelled.
In an warning issued early Wednesday, National Weather Service called the storm "catastrophic ... crippling ... paralyzing ... choose your adjective."
Forecasters warned of more than an inch (2.5 centimeters) of ice possible in places. Snow was forecast overnight, with up to 3 inches (7.6 centimeters) possible in Atlanta and much higher amounts in the Carolinas.
President Barack Obama declared a disaster in South Carolina and for parts of Georgia, opening the way for federal aid. In Myrtle Beach, South Carolina, palm trees were covered with a thick crust of ice.
The storm didn't cause the widespread highway problems in Atlanta that the last storm did, largely because people had learned their lesson. Streets and highways were largely deserted.
The storm then moved northward, threatening to bring more than a foot (30 centimeters) of snow Thursday to the mid-Atlantic and Northeast.
Washington D.C. could get up to 8 inches (20 centimeters) of snow. New York City could see 6 inches (15 centimeters).
Federal offices in the Washington, D.C., area will be closed on Thursday, the government announced late Wednesday.
Ice combined with wind gusts up to 30 mph (48 kph) snapped tree limbs and power lines. More than 200,000 homes and businesses lost electricity in Georgia, 130,000 in South Carolina and nearly 30,000 in Louisiana. Some people could be in the dark for days. AP