Federal officials warn residents to prepare for heavy winds, inland and coastal flooding and power outages from Hurricane Sandy.

The storm, which is expected to come ashore somewhere along the east coast late Sunday into early Monday, is anticipated to affect 50-60 million people along the east coast, from the Carolinas to New England and extending west into West Virgina and the Ohio Valley.

Flooding, for now, is the main focus of forecasters and federal disaster response agencies, according to Louis Uccellini, director the National Oceanic and Atmospheric Administration Center For Environmental Prediction.

Uccellini said the "extent of heavy rainfall has a danger of flooding for Pennsylvania and Maryland and into northern Virginia.

"Given the amount of rainfall and the period of time that it's falling over, we expect the river flooding to be significant from about 48 hours from now on," Uccellini said. "We're looking at the river valleys in Pennsylvania and Maryland then into New Jersey very carefully."

Rick Knabb, director of the National Hurricane Center, said residents along the east coast should not down play the potential effects of Hurricane Sandy because they were not impacted by past storms.

"Every storm is different so if you were not impacted by a past storm that doesn't mean it will be exactly the same for you this time," said Knabb. "We have to keep our eye on the ball on this storm."

County and state officials in Maryland Friday called on residents to use the weekend to prepare for Hurricane Sandy.

Gov. Tom Corbett Friday declared a state of emergency for the state of Pennsylvania. 

Montgomery County officials and other jurisdictions urged residents to begin their own personal disaster preparations.

PECO has been preparing through the weekend for expected power outages.

Karen Muldone Geus, a PECO spokeswoman, said 255 emergency crews and 155 tree crews are ready to respond to the storm.

“This storm is an all hands on deck type storm,” she said, in a report on the Daily Local website. adding that crews from sister utilities in Louisiana, Mississippi, Tennessee, and Illinois were traveling to the area to provide extra manpower for the utility’s emergency response.

Forecasters now believe the remnants of Hurricane Sandy will make landfall along the east coast between the Mid-Atlantic and New England areas some time between Monday and Tuesday. The effects of the large, slow moving storm, will be felt before that.

"Because of the large size, weather will begin to deteriorate in advance of the center circulation and then we anticipate that the system will slow down after coming ashore on Tuesday into Wednesday," Knabb said, adding that the storm is "much more capable of producing large storm surge values in coastal areas and longer periods of damaging winds at the coast and inland over a larger area, and longer periods of heavy rain over a larger area."

"So, there's going to be an inland flood potential," Knabb said. "This is not just going to be a coastal event, although the hazards do start at the coast with the storm surge and exactly who gets the worst of the storm surge is difficult to pinpoint right now."

Also of concern to officials is the strong winds that are expected to cause extended power outages.

"Based upon the wind speeds, we don't expect substantial structural damages,"  Federal Emergency Management Agency Administrator Craig Fugate said. "What we think the primary impact is going to be is trees and tree limbs down and whatever roof damage from trees coming down as well as power lines. The primary concern with wind is going to be extensive, perhaps widespread power outages due trees coming down, limbs coming down."

The large size of the storm, which could potentially cover the eastern third of the country, will cause multiple weather-related problems that vary from region to region.

Once the storm makes land-fall, it is expected to track east to west before heading north and being taken up by a storm system coming out of Canada.

Strong winds are expected to affect areas as far west as the Ohio Valley and the Eastern Great Lakes. Rainfall totals north and northwest of the center of the storm could range from 5 to 8 inches. As much as two feet of snow could fall in areas of West Virginia and western North Carolina and Virginia, said Uccellini.

Forecasters are already seeing similarities between Hurricane Sandy, which some have dubbed "Frankenstorm," and other storms with historical impacts.

"I think the Perfect Storm in 1991 has some similarities and the major cyclone in November 1950, which actually served as the storm that everyone started doing modeling on, had similar characteristics," Uccellini said. "We see storms that have characteristics but each storm is different. Each is unique and we don't try to make the historical comparisons until after the event."

Federal disaster response officials continue to stress the importance of preparing for the storm in communities from North Carolina through New England.

Fugate said pinpointing the exact location of landfall is still not possible.

"Florida is out of play because they lifted the watches so that is about as good as it gets," said Fugate.

"We're really looking at this from the Outer Banks of North Carolina all the way to West Virginia and the Ohio Valley and back up to the New England states," said Fugate. It's just too big of an area and too early to say a specific area."

"This will not be a track or a points," said Fugate. "We're looking at the consequences not what the track will be."

 Resources:

• Federal Emergency Management Agency: www.FEMA.gov
• Preparedness Information: www.Ready.gov
• NOAA's National Hurricane Center: www.hurricanes.gov
• NOAA's National Weather Service: www.weather.gov
• NOAA's Environmental Visualization Lab: http://www.nnvl.noaa.gov/Default.php