As a deadly Hurricane Sandy treks north from the Caribbean to meet two other powerful winter storms, experts say it doesn't matter how strong the storm is when it hits land: The rare hybrid storm that follows will cause havoc over 800 miles (1,300 kilometers) from the East Coast to the Great Lakes.

"We're looking at impact of greater than 50 to 60 million people," says Louis Uccellini, head of environmental prediction for the National Oceanic and Atmospheric Administration. The Category 1 storm, packing sustained winds of 75 mph (120 kph), is expected to continue moving parallel to the Southeast coast most of the day Sunday and approach the coast of the mid-Atlantic states by Monday night.

Governors from North Carolina, where steady rains were whipped by gusting winds Saturday night, to Connecticut declared states of emergency. Delaware ordered mandatory evacuations for coastal communities by 8 p.m. Sunday.

Here's a look at AP photos of the storm and preparations so far in the U.S.: