Utilities and local government were rushing preparations Friday along the Mid-Atlantic and Northeast coasts of the United States, but officials inland also were preparing.

Meteorologists say it’s an almost-unprecedented weather development.

It will be a rare combination of three systems -- Hurricane Sandy, a strong mainland storm, and a surge of cold air from Canada -- and computer models Friday were in near-agreement that the storm will hit the U.S. coast. Meteorologists warned the public not to concentrate on the center of the storm, though, as the system’s wind field will be hundreds of miles wide.

“Sandy is expected to bring impacts to a large part of the U.S. East Coast into early next week,” said Michael Brennan, of the National Hurricane Center.

The predictions are dire. The storm is expected to still be tropical in nature -- a Category 1 hurricane -- with 80 mph winds when it reaches the coast in Delaware or New Jersey late Monday. As a post-tropical system, it still is forecast to have top winds of 60 mph in central Pennsylvania early Wednesday.

“The large wind field will likely drive a storm surge of 3 to 6 feet Monday and Tuesday to the right of where the center makes landfall, on the mid-Atlantic or New York coasts,” Weather Underground’s Masters said. “These storm surge heights will be among the highest ever recorded on the affected coasts.”

He said the European computer model predicts landfall in Delaware. The Global model calls for landfall near New York City. If that happens, Masters said, waves and water could top the Manhattan sea walls and flood parts of New York City’s subway system.

Storm impacts are expected to be felt in northern Virginia, Maryland, the District of Columbia, Delaware, New Jersey, New York, Connecticut, Rhode Island, Massachusetts, Pennsylvania, and even eastern Ohio.

Utilities are lining up out-of-state work crews and canceling employees' days off to deal with expected power outages. From county disaster chiefs to the federal government, emergency officials are warning the public to be prepared. And President Barack Obama was briefed aboard Air Force One.

“It's 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.”

National Oceanic and Atmospheric Administration forecaster Jim Cisco, who coined the nickname Frankenstorm, said: “We don't have many modern precedents for what the models are suggesting.”

And the storm will take its time leaving. The weather may not start clearing in the mid-Atlantic until the day after Halloween and Nov. 2 in the upper Northeast, Cisco said.

“It's almost a weeklong, five-day, six-day event,” he said from a NOAA forecast center in College Park, Md. “It's going to be a widespread, serious storm.”

It is likely to hit during a full moon, when tides are near their highest, increasing the risk of coastal flooding. And because many trees still have their leaves, they are more likely to topple in the event of wind and snow, meaning there could be widespread power outages lasting to Election Day.

Eastern states that saw outages that lasted for days after last year's freak Halloween snowstorm and Hurricane Irene in late August 2011 are already pressuring power companies to be more ready this time.

Asked if he expected utilities to be more prepared, Massachusetts Gov. Deval Patrick responded: “They'd better be.”

Jersey Central Power & Light, which was criticized for its response to Irene, notified employees to be ready for extended shifts. In Pennsylvania, PPL Corp. spokesman Michael Wood said, “We're in a much better place this year.”

New York Mayor Michael Bloomberg on Thursday said the city was striking a tone of calm preparedness.

“What we are doing is we are taking the kind of precautions you should expect us to do, and I don't think anyone should panic,” Bloomberg said. The city has opened an emergency situation room and activated its coastal storm plan.

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. Nor is this one like last year's Halloween storm, which was merely an early snowfall.

“The Perfect Storm only did $200 million of damage and I'm thinking a billion” this time, Masters said. “Yeah, it will be worse.”

As it made its way across the Caribbean, Sandy was blamed for at least 22 deaths. The 18th named storm of the Atlantic hurricane season hit the Bahamas after cutting across Cuba, where it tore roofs off homes and damaged fragile coffee and tomato crops.

Norje Pupo, a 66-year-old retiree in Holguin, was helping his son clean up early Thursday after an enormous tree toppled in his garden.

“The hurricane really hit us hard,” he said. “As you can see, we were very affected. The houses are not poorly made here, but some may have been damaged.”

The largest death toll was in Cuba, where 11 were killed. It was the largest death toll from a hurricane since 2005. Another 10 died in Haiti and one in Jamaica.