As Hurricane Sandy bears down on the East Coast, federal forecasters are warning that the massive storm could bring "life-threatening" storm surges, flooding, hurricane-force winds, heavy rain and even blizzardlike snowfall over an area stretching from the Carolinas to Canada, and west to Ohio.

The slow-moving storm, a rare and powerful hybrid of hurricane and nor'easter fueled by an influx of Arctic air, is expected to make landfall in New Jersey later today. Officials say 50 million to 60 million people lie in the storm's likely path, leaving one of the most densely populated areas of the country vulnerable to destructive floods and multi-day power outages.

"We're confident, unfortunately, at this point there is no avoiding a significant storm surge event over a large area," said Rick Knabb, director of NOAA's National Hurricane Center, on Saturday. "We can't just pinpoint who's going to get the worst of it."

NOAA's latest forecasts warn of the potential for hurricane-force winds from the northern Delmarva Peninsula to Cape Cod, Mass., and well inland, with rainfall totals topping 12 inches in some areas. Storm surge will also pose a major threat to public safety, with high tides projected to rise 6 to 11 feet above ground level in Long Island Sound, New York Harbor and New Jersey's Raritan Bay, and 4 to 8 feet over a broader area from Ocean City, Md., to southern New England.

"We're dealing with categories here we don't normally see," Louis Uccellini, director of the National Oceanic and Atmospheric Administration's National Centers for Environmental Prediction, told reporters Friday.

Sandy is also expected to dump 2 to 3 feet of snow in West Virginia's mountains, with smaller but still significant accumulation in eastern Kentucky, western Virginia and even North Carolina, along the Appalachian Range. And officials are warning that the storm could cause severe river flooding that could linger after Sandy exits those areas.

Adding to the pain, officials say, is the likelihood Sandy's northward movement will slow once the storm makes landfall today, making it a two-day -- or more -- event in many affected areas.

"The large size of this system is why it is so capable of producing a life-threatening storm surge for so many areas," Federal Emergency Management Agency Director Craig Fugate said during a call with reporters yesterday morning. "We're currently seeing tropical storm conditions in North Carolina even though the center of circulation is 250 miles to the southeast."

Flights and trains canceled, disaster teams dispatched
Sandy's vast breadth stopped Maryland Sen. Barbara Mikulski (D) in her tracks yesterday as she toured NOAA's forecast operations center in College Park, Md. "This is creepy," Mikulski said, peering at a live satellite image of the storm. "This is like a Spielberg movie."

The storm has already prompted a flurry of preparations, closures and cancellations up and down the East Coast.

FEMA has positioned disaster response teams throughout the region, Fugate said. And the agency has been conducting daily briefings for President Obama, who also met yesterday with the director of the National Hurricane Center, officials from the Defense and Energy departments, and -- by phone -- with governors and city officials from areas in Sandy's projected path.

"My message to the governors, as well as to the mayors, is anything they need, we will be there," Obama said yesterday in a statement released by the White House. "And we're going to cut through red tape. We're not going to get bogged down with a lot of rules. We want to make sure that we are anticipating and leaning forward into making sure we've got the best possible response to what is going to be a big and messy system."

Airlines have canceled flights into many East Coast airports, including Newark Liberty International, LaGuardia and John F. Kennedy International in the New York City area and Dulles International and Reagan National airports near Washington, D.C. Amtrak said yesterday that it would "cancel nearly all service on the Eastern Seaboard" today.

In Washington, the federal government, city offices and schools are shuttered today, and the Washington Metropolitan Area Transit Authority has suspended subway and bus service.

Just north of the city, in Beltsville, Md., cars waiting to fuel up jammed the parking lot of a Wawa gas station around 1 p.m. yesterday. Inside, an employee said the station's tanks of regular unleaded gasoline were running dry, unable to keep up with the sudden spike in demand.

Farther north, communities along New Jersey's southern and central coasts are under mandatory evacuation orders. In Ocean City, N.J., emergency sirens sounded yesterday afternoon as police blocked access to the bridges that connect the resort community, which sits on a narrow barrier island, to the mainland.

"This has the potential to be an historic storm, with widespread wind damage and power outages, inland and coastal flooding, and massive beach erosion," warned the National Weather Service office in Mount Holly, N.J., yesterday. "The combination of the heavy rain and prolonged wind will create the potential for long-lasting power outages and serious flooding. ... There will be major property damage, injuries are probably unavoidable, but the goal is zero fatalities."

But if the current forecast holds and Sandy makes landfall in central New Jersey, it is New York City that is expected to take one of the biggest hits from the storm.

Evacuations ordered in New York City
New York Gov. Andrew Cuomo suspended all subway, rail and bus service in the city yesterday starting at 7 p.m., as the downstate region braced for the prospect of mass water intrusion into underground transit, high winds and dangerous coastal flooding.

The Democrat's order was soon followed by an evacuation edict from New York City Mayor Michael Bloomberg (I), who made residents in low-lying parts of all five boroughs leave their homes for the time being, though he said the city government would open today.

The shutdown of the sprawling subway system marks the second year in a row a storm has forced it to curtail operations, following Hurricane Irene last year. The head of the Metropolitan Transportation Authority yesterday cautioned that the closure could continue through Tuesday, meaning it would be closed for two entire workdays.

Cuomo cited high winds as the primary reason for shutting down the subway, which until Hurricane Irene had never seen a systemwide closure. MTA's policy is to shutter mass transit when sustained winds reach an average of 39 miles per hour.

Surrounding islands were also evacuated, including Fire Island and New Jersey's barrier islands. Bridges and tunnels were set to be closed on a case-by-case basis.

To the south of the city, New Jersey Gov. Chris Christie (R) briefed reporters throughout the day as the Garden State prepared for landfall and possibly the brunt of the storm. He said the goal of all emergency services is to save lives and act as if the worst-case scenario is imminent.

"We need to prepare for the worst," he said. "If it turns out to be not as bad, that will be a happy event for all of us."

Devastating storm surge predicted
The National Hurricane Center, meanwhile, signaled that the storm surge in Long Island Sound, New York Harbor and Raritan Bay could be as high as 11 feet.

Uccellini, of NOAA's National Centers for Environmental Prediction, said New York's geography is working against it. Long Island Sound narrows as it approaches New York City, causing water to rise as it funnels through a smaller channel.

Compounding the threat of the storm surge are higher tides than normal because of today's full moon. The combination of these factors had some warning that this year's water dump could be much worse than Hurricane Irene, which caused extensive damage in upstate New York and New England.

Upmanu Lall, a hydroclimatology specialist at Columbia University, said this year's storm brings "quite a big difference with last year" that could mean big trouble.

"The predicted storm surge could in certain areas be devastating," Lall said. "This one is a late-season hurricane, interacting with a nor'easter, so the potential for a strong rainfall is higher."

He added that power outages are most likely in New Jersey.

"Impacts in the N.J. areas in particular could be greater since they have overhead power lines, which are susceptible to high winds," he said.

Elsewhere, there was some talk of East Coast refineries closing down operations in southern New Jersey and Pennsylvania. Hess Corp. told Reuters it planned on cutting rates at its Port Reading, N.J., plant, and other operators around the Philadelphia area were closely watching the storm's path to determine their next move.

Last but not least, all meetings at the United Nations are canceled today. A media representative said the closure may extend through Tuesday.

Sullivan reported from New York City.

Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC., 202-628-6500.