East Coast prepares for Hurricane Sandy

Last Updated 11:02 a.m. ET

(CBS/AP) After causing heavy damage and at least 40 deaths in the Caribbean, Hurricane Sandy is headed toward making landfall on the East Coast by Tuesday. No one can be certain how powerful it will become, but the signs are ominous.

Meteorologist and CBS News hurricane analyst David Bernard of CBS Station WFOR says the storm weakened slightly overnight to a tropical storm, but was upgraded this morning to a hurricane packing 75 mph winds.

As of late Saturday morning tropical storm-force winds are already near the coast of North Carolina.

(To watch meteorologist David Bernard explain the path of Hurricane Sandy click on the video player below.)

Sandy is expected to make landfall early Tuesday near the Delaware coast, then hit two winter weather systems as it moves inland, creating a hybrid monster storm that could bring nearly a foot of rain, high winds and up to 2 feet of snow.

Experts said the storm could be wider and stronger than Irene, which caused more than $15 billion in damage, and could rival the worst East Coast storm on record.

Bernard says the storm's massive wind field means tropical storm-force winds when it makes landfall spreads through all of New England and the Mid-Atlantic states - the most densely-populated part of the country.

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The message up and down the Eastern seaboard couldn't be clearer: Be prepared for days without electricity, as a storm that could be one for the history books.

At 11 a.m. ET Hurricane Sandy was about 190 miles north of Great Abaco Island in the Bahamas and 355 miles southeast of Charleston, S.C., moving at 9 mph. Maximum sustained winds are 75 mph.

Tropical storm warnings remain in effect for parts of coastal North and South Carolina and the Bahamas. Tropical storm watches were issued for coastal Georgia and Bermuda.

Tropical storm warnings for parts of Florida's East Coast have been discontinued.

Sandy was projected to hit the Atlantic Coast early Tuesday. As it turns back to the north and northwest and merges with colder air from a winter system, West Virginia and further west into eastern Ohio and southern Pennsylvania are expected to get snow. Forecasters were looking at the Delaware shore as the spot the storm will turn inland, bringing 10 inches of rain and extreme storm surges, said Louis Uccellini, environmental prediction director for the National Oceanic and Atmospheric Administration.

Up to 2 feet of snow was predicted to fall on West Virginia, with lighter snow in parts of Ohio and Pennsylvania. A wide swath of the East, measuring several hundreds of miles, will get persistent gale-force 50 mph winds, with some areas closer to storm landfall getting closer to 70 mph, said James Franklin, forecast chief for the National Hurricane Center in Miami.

Jersey Shore beach towns began issuing voluntary evacuations and protecting boardwalks. Atlantic City casinos made contingency plans to close, and officials advised residents of flood-prone areas to stay with family or be ready to leave. Several governors declared states of emergency. Airlines said to expect cancellations and waived change fees for passengers who want to reschedule.

On the boardwalk in Ocean City, Md., some business owners are already boarding up and heading out of town.

How worried is business owner Bill Purnell? "On a 10-point scale, this is a nine."

Ocean City Mayor Rick Meehan hasn't ordered an evacuation yet, but wants everyone ready just in case. "We are telling people to get prepared, go through your checklist, make sure you have all your supplies," he told CBS News.

Sandy is expected to hit the most densely-populated area in the U.S. Sixty-four million people, about one in five Americans - potentially lie in the storm's path. Last year Hurricane Irene caused a loss of power for more than 6 million households in this region. This time even more could be left in the dark.

"When you're facing 50-60-mile winds with all the leaves still on the trees and a soaking rain for a long period of time, we're going to see trees come [down]," said PSE&G President Ralph LaRossa.

Up and down the Eastern seaboard more than 20,000 utility workers are standing by to turn the power back on.

Five refineries along the threatened East Coast - that produce seven percent of the nation's gasoline - are expected to suspend operations as early as Sunday. That could put upward pressure on the price of gas.

The storm is even affecting the presidential campaign. Parts of three battleground states - North Carolina, Virginia, and Ohio - are directly in Sandy's path. Vice President Joe Biden already canceled an event that was scheduled for this morning in Virginia, and Mitt Romney cancelled a rally scheduled in Virginia tomorrow. Both campaigns are also worried that the storm could hurt affect early voting in those battleground states.