From AP and staff reports
LEWISTOWN - A cold front has moved farther south than anticipated, possibly taking with it much of the heavier snow forecast across the southern part of Pennsylvania into Monday, according to the National Weather Service.
The winter weather advisory that was in effect for most of the weekend was first modified and then canceled Sunday evening, as bitterly cold air from the north was expected to keep the bulk of the storm system - and the heavier snowfall - south of the Pennsylvania/Maryland state line.
Forecasters said Sunday night to expect significantly less snow accumulation than what was forecast at the beginning of the weekend, but urged motorists to still exercise caution while traveling as the Arctic chill was likely to create hazardous travel conditions across the state.
The Pennsylvania Turnpike remained under a Winter-Weather Warning Sunday night, and motorists were urged to stay alert for possible snow, poor visibility and slick roadways. Extra maintenance crews and State Police patrols remained on duty across the Turnpike to clear the roadway and assist motorists as needed.
The state's major cities are breathing a little easier with the updated forecast. Michael Kennedy, the senior meteorologist at the National Weather Center's suburban Pittsburgh office, said the city will now probably receive about four inches of snow, far less than the six to eight inches forecast earlier Sunday.
The weather service had been calling for six to eight inches of snow across the southern quarter of the state, with lesser amounts farther north, except for higher elevations like the Laurel Mountains in western Pennsylvania and the Poconos in the east. Now most areas of the state could receive less than first predicted - perhaps a little more than half, Kennedy said.
Despite that, a winter storm warning remained in effect across the state's southern counties, where it was expected to end at 1 p.m. Monday in the Philadelphia area.
"The trend has been to pull the front south, everything has just gone south," Kennedy said.
Dire forecasts from a few days ago, which predicted the storm would drop up to a foot of snow on some parts of southern Pennsylvania, were based on an expected one-two punch of snow, Kennedy said.
The first band arrived in western Pennsylvania as predicted, though a bit sooner than originally thought, as snow began falling in Pittsburgh and surrounding areas about dawn Sunday. That system tapered off in the afternoon in western Pennsylvania, and was expected to bring freezing rain turning to snow farther east as night fell.
A second band of snow was expected to hit western Pennsylvania after midnight and dump more snow into early Monday afternoon as it moved through Philadelphia. But it now appears the second system will stay farther south, either missing southern Pennsylvania or dropping far less snow than originally predicted, Kennedy said.
"That's the main difference in how the forecast has really changed, the second wave is not going to be as significant as first thought," Kennedy said.
Still, officials weren't taking chances.
Pittsburgh Mayor Bill Peduto said crews were pretreating bridges, hills and curves on busy roads, and some 24 snow plows were waiting to be deployed if the second wave of snow makes that necessary.
"The forecast and the storm can change quickly and the Department of Public Works remains at the ready for a much larger snow event should the city receive one," Peduto said in a statement.
Later Sunday, Philadelphia Mayor Michael Nutter planned to announce that city's snow removal plans, and the Pennsylvania Department of Transportation planned a similar briefing at its offices in suburban Norristown.
The Southeastern Pennsylvania Transit Authority planned to begin alerting commuters to weather-related detours and delays of bus and train service by 4 a.m. Monday. And Amtrak announced it would operate on a modified snow schedule in the Northeast on Monday, including fewer trains providing Keystone Service from Harrisburg through Philadelphia to New York.