Rehobeth Beach, DE -- Sandy is back to hurricane status after briefly being downgraded to a tropical storm. Regardless of its status, experts expect a powerful storm to hit the east coast on Monday.

From the Carolinas to New England, the entire eastern seaboard is keeping an eye on the news for the latest on Sandy.

Sandy is a big storm with winds greater than 58 miles an hour expected throughout much of the east coast.

CBS News Hurricane Consultant David Bernard says, "Because of the sheer size of this storm, it's been pushing an enormous amount of water along."

Experts are warning people to take the storm seriously and start preparing now.

Pennsylvania's Governor Tom Corbett says, "Probably 40% of the population of the United States could be affected by this."

Some towns are taking extra precautions to fight the flooding. In Virginia Beach, they've built six foot tall sand walls.

David Bernard says, "Storm surge risk is extreme. The risk of flooding here may be some of the greatest flooding that people have seen in their local areas, maybe in their lifetimes."

People in Delaware and all along the east coast are getting ready for Sandy's effects.

The big fear is that further inland, Sandy will combine with a wintry storm system to bring severe rain, winds and snow.

Dozens of utility providers have crews on standby in several states.

Nervous neighbors are hitting hardware stores stocking up on generators and flashlights.

People have been told to prepare for power outages that could last several days.

Governors in North Carolina, Virginia, Maryland, Pennsylvania and New York and have already declared states of emergency.