Flooding is possible as Hurricane Sandy makes its way up the coast before turning west and striking the area with rain and tropical storm-force winds.
"It's going to be an extended period of wet and windy weather," said Craig Evanego, meteorologist for National Weather Services, State College.
As of Friday afternoon, 2 to 4 inches of rain is expected across central Pennsylvania, with higher amounts possible.
"That's quite a bit of rain," Evanego said. "Fortunately, we're starting a little on the dry side."
Yet even starting dryer than normal, flooding still will be possible.
Mayor Gabriel J. Campana and his staff are asking residents to refrain from raking leaves this weekend and piling them in the streets where they could impede the water flow by cluttering up the drains and gutters, which could cause water backup problems.
A front also will be approaching today, bringing showers in the afternoon into the night.
As Sandy comes up the coast, the front will be on top of the area, which will bring rain Monday into Tuesday, heavy at times.
The wind is expected late Monday into Tuesday, but it is too early to tell how damaging the winds could be.
"Hopefully by Wednesday or Wednesday night, we finally get everything to pull north of us," Evanego said.
The storm is expected to follow the East Coast until somewhere near Virginia Beach when it likely will move northwest and hit land around New York City or the Delmarva Peninsula, which is occupied by most of Delaware and portions of Maryland and Virginia.
A large number of people are expected to be affected, as the storm is possible to hit anyone from Virginia Beach to Washington, D.C., to Baltimore, all the way to New York City, he said.
Once the hurricane is over land, the winds will start to weaken, Evanego said.
Because of Hurricane Sandy, Gov. Tom Corbett urged Pennsylvanians on Friday to prepare for a storm that could hit the entire state with a combination of damaging winds, rain and snow.
"It appears that, worst-case scenario, it could be a storm that affects all of Pennsylvania, rain on one side, snow on the other side," Corbett said. "This is the time to start preparing."
Though he urged preparedness, Corbett cautioned against rushing to buy provisions, saying "you still have time here."
State emergency management officials told residents to have three days of supplies at home, including batteries, water and food, in case of widespread power outages.
PPL Electric Utilities is preparing for potentially significant damage and power outages.
"According to current forecasts, this could be the most severe storm to date this year," David Bonenberger, vice president of Distribution Operations, said in a news release. "We're continuously monitoring weather reports, and we'll have the necessary crews and resources in place to respond to whatever comes our way."
Customers experiencing outages are asked to report them at 1-800-342-5775 (1-800-DIAL PPL) or through the online Outage Center at www.pplelectric.com/outagecenter. When prompted, customers reporting by phone should press 1 for "Power Problem." The Outage Center also is available on smart phones or other mobile devices.
PPL Electric Utilities advises the public to:
* Stay clear of downed power lines.
* Do not use gas ovens or ranges to heat your home.
* Avoid candles and use flashlights instead. Candles can cause a fire if tipped by animals or people, or if they come in contact with a combustible item.
* Never run a generator in a home, basement, or other indoor space where exhaust fumes may accumulate.