As of 11 p.m., Sandy was centered about 360 miles east-southeast of Charleston and 305 miles south of Cape Hatteras, North Carolina, according to the National Hurricane Center. Now heading northeast at a 14 mph rate, the storm is expected eventually to boomerang toward the shore and begin seriously impacting heavily populated areas Sunday.
Forecasters are still trying to pinpoint where it will its biggest impact when it finally does come entirely over land. Computer models show it striking somewhere along a roughly 700-mile stretch -- from North Carolina to as far north as Connecticut.
Its potential merger with the cold front could "energize this system" and make it more powerful, said Louis Uccellini, who is responsible for environmental prediction at the National Oceanic and Atmospheric Administration.
Such a scenario is not unlike the weather system that led to 1991's "Perfect Storm," when moisture flung north by Hurricane Grace combined with a high pressure system and a cold front to produce a tempest in the north Atlantic during Halloween. But Grace never made landfall.
Anne Kennedy headed on Saturday to RFK Stadium, like many other Washington, D.C., residents, to fill up her car's trunk with sandbags that she'll pass onto her daughter, who has two babies at home. Amid all the frenzy, Kennedy said she's gotten the point.
"I just turned off the news," she said. "It's too much."
Some have resigned themselves to the fact that Mother Nature is in charge -- and that, whatever they do, it won't stop the wind, rain or storm surges.
"The most stressful thing is to stand in your house, watch the water come up, and there's nothing you can do," Norfolk, Virginia, resident Bill Sawyer told CNN affiliate WVEC.
"It's going to keep coming. And then you're stuck, because now you can't get out of your house."