Heaviest rains in four months and 50 mph wind gusts are possible in the Philly region Wednesday
Power outages are possible as winds could gust to 50 mph Wednesday at the Shore and on the mainland.
A potent storm is likely to generate the Philadelphia region’s heaviest rainfall in over four months and could set off thunderstorms with gusts of up to 50 mph Wednesday afternoon, with some power outages possible.
A general 1.5 to 2.5 inches of rain, with isolated amounts up to 3 inches, was expected to have fallen by the time it shuts off Wednesday night.
Are you missing the drought yet? No worries: The rains won’t be enough to liquidate the region’s drought conditions, and the drought advisories are all but certain to remain in effect. However, if the forecasts hold, this would be the most precipitation since the rains of Aug. 6 to 9, when just under 3 inches was measured at Philadelphia International Airport.
One indication of this storm’s ferocity is the fact that its powerful south winds have drivenwill drive temperatures into the 60s, and they may flirt with a record for the date. Readings then will head precipitously in the other direction.
Given the freshly saturated ground and the gust potential, there could be some power outages and tree damage, said Paul Fitzsimmons, a lead forecaster at the National Weather Service office in Mount Holly. “But probably nothing that would be hugely widespread.”
Said Peco spokesperson Brian Ahrens: “It’s on our radar.”
What time is the storm expected to peak in the Philadelphia region?
The best estimate for the peak winds in the immediate Philadelphia area would be 2 to 4 p.m. Wednesday, said Bob Larsen, senior meteorologist with AccuWeather. That’s the best estimate for a potential squall line and thunderstorms moving through the area, he added, and subject to change, of course.
The center of the storm, whose intensity could reach the technical threshold to qualify as a “bomb,” he said, will follow a southwest-northeast path passing west of Philly. Since the region will be east of the center, it will experience powerful, warm southerly winds as part of the storm’s counterclockwise circulation.
The cold front trailing the storm is forecast to approach the region during the afternoon, and after it passes the winds will become westerly. They will continue to howl Thursday, but not quite as briskly as on the day before, forecasters said.
A wind advisory is up for the Jersey Shore from noon to 8 p.m. Wednesday for gusts to 50 mph, but inland areas could experience similar peak gusts in any thunderstorms, said the weather service’s Fitzsimmons.
The gusts, he said, will depend on how much of the potent winds in the upper atmosphere mix down to the surface.
Is flooding a concern for the Philadelphia region?
Other than road ponding and areas around leaf-clogged drains, no.
Under normal conditions, amounts in a league with those forecasts might merit a flood watch.
But the rain deficits — more than 8 inches in Philadelphia in the last 90 days — remain prodigious, and the river and stream levels remain way, way down.
How cold will it get after the storm departs?
Very. This will be the coldest air of the season so far. Temperatures won’t get out of the 30s on Thursday or Friday, and may fall into the teens in areas outside the city Friday morning.
That will be followed by a weekend warm-up — and more rain — although it won’t be quite as warm as it will be on Wednesday.
The highs are forecast to reach the mid-60s; the record for Dec. 11 is 68 degrees, set in 2021.
Of note, in 1966, readings reached 70 on both Dec. 9 and 10, followed by a foot of snow on Christmas.