DUCK, N.C. — A year after being walloped by Hurricane Irene, residents rushed to put away boats, harvest crops and sandbag boardwalks Friday as the Eastern Seaboard braced for a rare megastorm that experts said would cause much greater havoc.

Hurricane Sandy, moving north from the Caribbean, was expected to make landfall Monday night 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 would be wider and stronger than last year’s Irene, which caused more than $15 billion in damage, and could rival the worst East Coast storm on record.

Officials did not mince words, telling people to be prepared for several days without electricity. 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. Airlines said to expect cancellations and waived change fees for passengers who want to reschedule.

“Be forewarned,” said Connecticut Gov. Dannel P. Malloy. “Assume that you will be in the midst of flooding conditions, the likes of which you may not have seen at any of the major storms that have occurred over the last 30 years.”

Many storm-seasoned residents had not begun to panic. Along North Carolina’s fragile Outer Banks, no evacuations had been ordered and ferries hadn’t yet been closed. Plenty of stores remained open and houses still featured Halloween decorations outside, as rain started to roll in.

“I’ll never evacuate again,” said Lori Hilby, manager of a natural foods market in Duck, N.C., who left her home before Hurricane Irene struck last August. “... Whenever I evacuate, I always end up somewhere and they lose power and my house is fine. So I’m always wishing I was home.”

Farther north, residents were making more cautious preparations. Patrick and Heather Peters pulled into their driveway in Bloomsburg, Pa., with a kerosene heater, 12 gallons of water, paper plates, batteries, flashlights and the last lantern on Wal-Mart’s shelf. They’ve also rented a U-Haul in case the forecast gets worse over the weekend.

“I’m not screwing around this time,” said Heather Peters, whose town was devastated last year by flooding following Hurricane Irene.

Across the street, Douglas Jumper, whose first floor took on nearly 5 feet of water during Irene, was tying down his patio furniture on Friday and moving items in his wood shop to higher ground.

“I’m tired. I am tired,” Jumper, who turns 58 on Saturday, said through tears. “We don’t need this again.”

At a Home Depot in Freeport, on Long Island in New York, Bob Notheis bought sawhorses to put his furniture on inside his home.

“I’m just worried about how bad it’s going to be with the tidal surge,” he said. “Irene was kind of rough on me and I’m just trying to prepare.”

The storm threatened to hit two weeks before Election Day, while several states were heavily involved in campaigning, canvassing and get-out-the-vote efforts. Republican presidential nominee Mitt Romney and Vice President Joe Biden both canceled weekend campaign events in coastal Virginia Beach, Va., though their events in other parts of the states were going on as planned. In Rhode Island, politicians asked supporters to take down yard signs for fear they might turn into projectiles in the storm.

After Irene left millions without power, utilities were taking no chances and were lining up extra crews and tree-trimmers. Wind threatened to topple power lines, and trees that still have leaves could be weighed down by snow and fall over if the weight becomes too much.

In upstate New York, Richard Ball was plucking carrots, potatoes, beets and other crops from the ground as quickly as possible. Ball was still shaky from Irene, which scoured away soil, ruined crops and killed livestock last year.

Farmers were moving tractors and other equipment to high ground, and some families pondered moving furniture to upper stories in their homes.

“The fear we have a similar recipe to Irene has really intensified anxieties in town,” Ball said Friday.

Sandy has killed at least 40 people in the Caribbean, and just left the Bahamas. Residents from Florida to North Carolina will experience peripheral impacts of the hurricane through the weekend.

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 should 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.

“It’s going to be a long-lasting event, two to three days of impact for a lot of people,” Franklin said. “Wind damage, widespread power outages, heavy rainfall, inland flooding and somebody is going to get a significant surge event.”

Nonetheless, some residents were still shrugging off the impending storm.

On North Carolina’s Ocracoke Island, which suffered a direct hit from Irene, the grocery side of Tommy Hutcherson’s Ocracoke Variety Store was bustling. But few people had been shopping on the hardware side.

“People go through this all the time around here. It’s not the first time and it won’t be the last,” Hutcherson said.

Last year’s Hurricane Irene was a minimal hurricane that caused widespread damage as it moved north along the coast after making landfall in North Carolina. With catastrophic inland flooding in New Jersey, Massachusetts and Vermont, federal officials say Irene caused $15.8 billion in damage.

Sandy is “looking like a very serious storm that could be historic,” said Jeff Masters, meteorology director of the forecasting service Weather Underground. “Mother Nature is not saying, ‘Trick or treat.’ It’s just going to give tricks.”

Some have compared the tempest to the so-called Perfect Storm that struck off the coast of New England in 1991, but that one hit a less populated area.

Masters said this could be as big, perhaps bigger, than the worst East Coast storm on record, a 1938 New England hurricane that is sometimes known as the Long Island Express, which killed nearly 800 people.

If the storm hits farther north than forecast and comes in closer to Long Island — which is still well within the National Hurricane Center’s cone of uncertainty for where the storm can come ashore — storm surge in the New York City area could be 3 to 6 feet, which might be enough to put water into the New York City subway system, Masters said. Last year Irene missed doing that by only eight inches, he said.

If the storm hits farther south, closer to Washington D.C., those areas could be doused with extreme storm surge and rain.

“You’re preparing for the worst and praying for the best, and whatever God can do to keep it from whacking, we’d appreciate it,” said Kevin Boyle, administrator of the borough of Pompton Lakes, N.J.