Nor’easter: Snow, damaging winds, floods likely

Still recovering from the unprecedented ravages of Sandy, the region is primed for an extraordinary foretaste of winter with the potential for heavy, wet snow; gale-force gusts; and January-type wind-chills.

The National Weather Service has posted a coastal-flood warning for the Jersey Shore for Wednesday into Thursday morning and a "winter weather advisory" for accumulating snow for Philadelphia and the neighboring counties on both sides of the river.

If the region has ever experienced such a sequence - a wintry storm within 10 days of a severe battering by a hybrid tropical cyclone - no one could recall it.

"If we have locusts next week, you know we're really in trouble," said Gary Szatkowski, meteorologist in charge of the National Weather Service in Mount Holly.

The storm's wintry turn, however, could constitute a break for the Jersey Shore. The strongest winds will be blowing mostly from the cold north, rather than directly onshore.

That said, wind gusts up to 65 m.p.h. at the beaches and up to 50 m.p.h. on the mainland, where snow is a real threat, could result in fresh rounds of extensive power outages.

"It's going to cause problems," said Henry Margusity, a meteorologist with AccuWeather Inc. Margusity said from two to four inches could fall in the region. The official National Weather Service forecast was for one to three inches, but Szatkowski said the computer-model guidance varied from nothing to 10 inches. Margusity said the U.S. forecast model suggested up to seven inches.

The higher amounts likely would accumulate in the far northern and western suburbs, but wet snow could fall even at the Shore.

Temperatures will fall into the 30s, and the winds could drive windchill values deep into the 20s, a major concern for anyone who might lose power.

Szatkowski said that given the wind direction and the generally low astronomical tides, major coastal flooding was unlikely, but moderate coastal flooding was expected during high tide tomorrow afternoon.

Stewart Farrell, director of the Richard Stockton Coastal Research Center and an erosion expert, said the most vulnerable beaches would be in the Atlantic City area and on Long Beach Island.

Speaking in Westwood, N.J., on Tuesday, Gov. Christie said that while he was concerned about what the nor'easter might do to beaches compromised by Sandy, he did not plan to close off the barrier islands.

The Army Corps of Engineers, which is deeply invested in sand-pumping projects on the Jersey coast, said the latest threat was a source of anxiety, coming after Sandy. "There was extensive damage to all our projects," said Corps spokesman Steven Rochette.

The storm, which is expected to track north off the mid-Atlantic coast, would be well positioned to generate cold winds from the north that would drop temperatures and turn rain to snow, Margusity said. Winds circulate counterclockwise around centers of low pressure; areas to the west thus experience winds from the north.

The rain is forecast to begin by afternoon and possibly turn to snow late in the day and continue during the night. It could snow hard for a while, but temperatures probably will stay above freezing, at least in the city, and snow will have a hard time sticking.

Should measurable snowfall in Philadelphia, it would be quite an anomaly.

Only three times in the period of record, dating to the 1880s, has that happened by the first week in November. One of those, of course, was Oct. 29, 2011, when Philadelphia measured all of 0.3 inches, but more fell elsewhere. The others were on Oct. 10, 1979, 2.1 inches in Philadelphia, and Nov. 6, 1953, the standard for November storms.

This one is unlikely to match the '53 storm, during which 8.8 inches was recorded at Philadelphia International Airport. "Let's not panic," Szatkowski said.