(USA TODAY) - An ominous pre-Halloween hurricane -- dubbed "Frankenstorm" for its potential monstrous effects -- has millions bracing for a ferocious weather system likely to drench much of the East coast by early Monday.

For the 50 million people who live in the Mid-Atlantic and Northeast - roughly one-sixth of the U.S. population - Hurricane Sandy's winds, rains and potential snow could cause widespread havoc, with weather forecasters predicting up to 10 inches of rain in some regions, snowstorms in others and widespread wind damage that could down power lines.

At least 38 deaths in Cuba, Jamaica and Haiti were already reported in Sandy's wake, including a 4-month-old Cuban boy crushed when his home collapsed. There were no reports of injuries at the U.S. naval base at Guantanamo Bay.

"This will be a long-lasting event, with two to three days of impact," said James Franklin, branch chief of the National Hurricane Center. "Wind damage, widespread power outages, inland flooding and storm surge are all likely."

Although mostly out at sea today and weakening slightly, Sandy is still gearing up for an assault from South Carolina to New England. Weather forecasters said the storm will likely run into a cold front approaching from the Midwest, which could dump up to two feet of snow in parts of West Virginia and Virginia.

"This is a very unusual weather event as a result of a late season hurricane combining with cold front from the West,'' said Virginia Gov. Robert McDonnell, who declared a state emergency Friday in advance of the storm to aid disaster preparations. "This is still an unpredictable weather event, but one that's possibly very dangerous."

As of 2:30 p.m. ET Friday, the center of Hurricane Sandy was located about 30 miles north-northeast of Great Abaco Island in the Bahamas. That's 430 miles south-southeast of Charleston, S.C.

Sandy remains a Category 1 hurricane, but just barely, with a sustained wind speed of 75 mph. It is crawling to the north at about 7 mph.

Winds and rain from Sandy, now grazing Florida, are predicted Saturday and Sunday along the coast of the Carolinas. But the main onslaught is forecast for Monday and Tuesday in the Mid-Atlantic and Northeast. "We are now 90% certain the storm will make landfall in the U.S.," said Louis Uccellini, director of NOAA's National Centers for Environmental Prediction.

AccuWeather meteorologist Tom Kines says winds could have the biggest impact, causing widespread power outages. "You've got to be concerned since it's an area with such a large population," Kines says.

Delaware was bracing for a threat rivaling the March 1962 nor'easter that has stood as the state's worst storm. Delaware's top environmental officer, Dept. Natural Resources and Environmental Control Sec. Collin O'Mara, said Sandy could unleash record waves and tidal flooding along the coast.

"The potential on this is greater than the defenses that we have in most places," O'Mara said. "We're taking this as an extremely significant problem, probably the most-significant we've seen in decades. We're taking every possible precaution."

LIVE TRACKER: See where Sandy is now, where it's headed

Tropical storm conditions threatened Florida's southeastern coast, the Upper Keys and Florida Bay Friday.

Florida officials say they don't expect flooding but have already warned residents to stock up on supplies and be prepared for several days without power.

"We encourage people to have enough food, water, medicines, flashlights and batteries -- things to take care of yourself for at least 72 hours," said Bryan Koon, director of Florida's Division of Emergency Management.

Forecasters expect the bulk of Hurricane Sandy's influence on Florida's Space Coast to hit Friday, building on an already stormy foundation and rough seas.

"We're looking at deteriorating weather conditions throughout Brevard," said Tony Cristaldi, a meteorologist with the NWS in Melbourne.

The center of the hurricane will remain about 170 to 200 miles off Brevard County's coast at its closest point later Friday night.

"We are expecting sustained winds and gusty winds, so if you have items outside your home that are likely to become airborne, you'll want to secure those," Brevard County Emergency Manager Kimberly Prosser said. "Things like garbage cans and lawn furniture."

The high winds would extend inland, Weather Channel meteorologist Chris Dolce says, with the potential for downed trees and power lines. Power outages could last for days, Dolce says, and there could be just enough cold air to produce wet snow, possibly heavy, in some parts of the central Appalachian mountains of West Virginia and Pennsylvania.

Pepco, the electric company that provides service to Washington, D.C., and parts of Maryland, has already activated emergency teams and begun scheduling workers who might have to assess damage, restore power and coordinate with other power companies in the region, spokesman Marcus Beal said.

"We're already making plans and working as if this is a definite event," he said.

Officials in places like Pennsylvania, New Jersey and Massachusetts are monitoring the storm and getting prepared in case people need emergency supplies, volunteers or shelters.

"We want to make sure we are connecting with everybody and that we will have a game plan in place if the storm requires us to respond," said Paul Shipman, a spokesman for the American Red Cross in Connecticut and Rhode Island. He added that volunteers have already been called to be on alert.

The Red Cross will work with local media and local towns, and will use its social media outlets to get the word out about the storm, Shipman said. He encouraged iPhone and Android users to download the Red Cross' Hurricane app.

Several East Coast residents and business owners said Thursday they weren't making any major plans just yet.

Randal Anderson, the dock master at Inlet Marina in Melbourne, Fla., said he plans to secure the boats and take down the paper ghosts lining his home's fence.

"I'm going to take down the Halloween decorations since we're expecting 50-mph gusts," he said. "I'm not in panic mode. I've lived here all my life. This is what we do."

Meanwhile, landfall Monday along the Mid-Atlantic coast, as predicted by two of the weather models, "would likely be a billion-dollar disaster," according to Weather Underground meteorologist Jeff Masters. Additionally, Masters reminds the public that the full moon is on Monday, which means astronomical tides will be at their peak for the month, increasing potential storm surge flooding.

What's creating this monster? A combination of Hurricane Sandy and another storm over the eastern USA, writes meteorologist James Cisco of the Hydrometeorological Prediction Center in an online report.

The winds from Sandy, Cisco writes, will be "incorporated into a hybrid vortex over the Mid-Atlantic and Northeast next Tuesday." This "unusual merger ... should settle back toward the interior Northeast through Halloween, inviting perhaps a ghoulish nickname for the cyclone along the lines of 'Frankenstorm,' an allusion to Mary Shelley's gothic creature of synthesized elements."

On Friday, Allstate Insurance Co. was in the midst of expanding efforts to prepare for Hurricane Sandy, spokeswoman April Eaton said.

"We are currently rolling our catastrophe personnel, mobile claim centers and catastrophe response vehicles to Raleigh, N.C., for staging," she said. "Staging allows us to get our national catastrophe team members and units positioned in a safe place, but close to areas that may be impacted by Sandy. Once we see where the hurricane makes landfall, and authorities allow us in, we're able to move from the staging area or holding pattern and go into the heavily damaged communities to help Allstate customers begin the claim process."

Eaton said they plan to send nine mobile claim centers to Raleigh, N.C., and Allentown, Pa.