Heavy rains and 50-mph wind gusts could cause outages and commuting woes around Philly

While what’s left of the of the season’s first snowfall is likely to be gone with the wind, heavy rains, followed by winds gusting to 50 mph, could cause some commuting issues Friday.

The National Weather Service issued a 24-hour high-wind advisory for the entire region for gusts to 50 mph that was to go in effect at 1 a.m. Friday.

The heaviest rains are expected to fall from the early-morning hours through midmorning, said Paul Fitzsimmons, a lead meteorologist at the weather service’s Mount Holly office.

“It will be a little rough,” he said. “We wouldn’t be surprised to see road-ponding, urban-type flooding.”

With snow melt conspiring with the rains to saturate the soils, SEPTA is particularly concerned about the potential for uprooted trees along its Regional Rail lines, said media relations director Andrew Busch.

“The recipe for problems is there,” he said. “We will have crews stationed across the system to respond quickly.”

Peco has heard the rumors, and while the utility is “not expecting impacts, we’re gong to continue to monitor conditions,“ said Candice Womer, senior communications specialist.

The deciduous trees are mostly bare, so winds can sail through branches that are not weighed down with leaves, but the weather service advises that “some power outages” are possible.

An additional concern was the predicted wind shift, from southerly in the morning to westerly in the afternoon, and how that might stress vulnerable trees, Womer said.

The weather service said heavy rains were expected between 8 and 11 a.m.

They would be accompanying a potent cold front that could generate “locally damaging winds,” it said.

The gusts are likely to be localized in the morning, and “the widespread strong winds” will occur in the afternoon, Fitzsimmons said. That would be after the front migrates through the region and winds become westerly, peaking in time for the afternoon commute. Gusts to 50 mph are possible.

Rain totals in the Philly area are expected to be in the 1-to-1.5-inch range, Fitzsimmons said.

No stream flooding is anticipated, however, as levels are quite low. Despite the snow and a decent soaking on Dec. 2, precipitation the last two months is only about 75% of normal throughout the region, according to the National Oceanic and Atmospheric Administration’s Middle Atlantic River Forecast Center.

The gusts aside — not a trivial omission — this system should produce a “beneficial rain,” the weather service notes.

A drought warning remains in effect for all of New Jersey.

Water levels are so low that computer models show only about a 10% chance of streams reaching even the preflood “action” phase.

In the interagency U.S. Drought Monitor map posted Thursday morning, most of Philadelphia, adjacent South Jersey, and Chester County were in the “severe drought” category, along with portions of Bucks, Delaware, and Montgomery Counties.

Most of Pennsylvania and New Jersey were in at least “abnormally dry” conditions.

After the winds die down Friday evening, the region should be in for a dry but chilly weekend.

Temperatures during the day Friday are forecast to dive from a high in the 50s in the morning to the 30s by nightfall, and they won’t get out of the 30s on Saturday.

Sunday’s forecast high in the mid-40s would be close to normal for the date.

Peeking ahead, the prospects of a white Christmas are not especially promising.

The region may have to settle for a wet one. Rain is possible Christmas Day with highs in the 40s. That’s not quite what Irving Berlin had in mind.