ATLANTA — The city dodged the first punch of a dangerous winter storm Tuesday, but forecasters warned of a potentially ‘‘catastrophic’’ second blow in a thick layer of ice that threatened to bring hundreds of thousands of power outages and leave people in their cold, dark homes for days.
The streets and highways in metro Atlanta were largely deserted as people in the South’s business hub heeded advice from officials to hunker down at home, especially after the snow jam two weeks ago saw thousands of people stranded on icy, gridlocked roads for hours when 2 inches of snow fell.
‘‘Last time I was totally unprepared, I was completely blindsided,’’ said Lisa Nadir, of Acworth, who sat in traffic for 13 hours and then spent the night in her car when the storm hit Jan. 28. ‘‘I’m going to be prepared from now on for the rest of my life.’’
Nadir was telecommuting from home Tuesday and she had kitty litter in her trunk in case she needed to put it down on icy roads for extra traction.
The forecast drew comparisons to an ice storm in the Atlanta area in 2000 that left more than 500,000 homes and businesses without power and an epic storm in 1973 that caused an estimated 200,000 outages for several days. In 2000, damage estimates topped $35 million.
Eli Jacks, a meteorologist with National Weather Service, said forecasters use words like ‘‘catastrophic’’ sparingly.
‘‘Sometimes we want to tell them, ‘Hey, listen, this warning is different. This is really extremely dangerous and it doesn’t happen very often,’ ’’ Jacks said.
‘‘I think three-quarters of an inch of ice anywhere would be catastrophic,’’ Jacks said.
But the Atlanta area and other parts of the South are particularly vulnerable because there are so many trees and limbs hanging over power lines. When the ice builds up on them, limbs snap and fall, knocking out power.
‘‘There is no doubt that this is one of Mother Nature’s worst kinds of storms that can be inflicted on the South, and that is ice. It is our biggest enemy,’’ Georgia Governor Nathan Deal said.
While only light rain fell in Atlanta on Tuesday, cities 40 miles northwest saw 2 to 3 inches of snow. The rain was expected to turn into sleet and freezing rain overnight.
More than 200 utility vehicles from Florida, North Carolina, and other Southern states gathered in a parking lot near one of the grandstands at Atlanta Motor Speedway. The state had more than 22,000 tons of salt, 70,000 gallons of brine, and 45,000 tons of gravel and brought in 180 tons of additional salt and sand. The goal was to make sure at least two interstate lanes were available in each direction. Then material would be used on the most heavily used roads off the highways. Officials were also considering rerouting traffic in extreme circumstances.
Hundreds of Georgia National Guard troops were on standby in case evacuations were needed at hospitals or nursing homes, and more than 70 shelters were set to open. President Obama declared a state of emergency in Georgia, ordering federal agencies to help the state and local response during the storm. Deal said a priority for that request was generators.
Metro Atlanta, the economic engine of the South with the headquarters of Fortune 500 companies including Home Depot, UPS, Delta Air Lines, and Coca-Cola, resembled a ghost town. Schools were closed and grocery store shelves were bare of milk and bread.