Philadelphia could experience more snow this weekend than it did during the the entire winter of 2024-25, but the forecast updates Friday suggested that may not be the worst of the storm’s offerings.
In issuing a profoundly predictable winter storm warning, in effect from 7 p.m. Saturday until 1 p.m. Monday, the National Weather Service said that in addition to 8 to 12 inches of snow, as much as a quarter-inch of freezing rain could accumulate. That would greatly increase the power outage potential.
Whatever the outcome, the storm still in its formative stage already has had significant impacts on the region and may have set an unofficial record for pre-storm buildup and preemptive closings.
Philadelphia Mayor Cherelle L. Parker declared a state of emergency for Sunday, as did Pennsylvania Gov. Josh Shapiro and New Jersey Gov. Mikie Sherrill. PennDot is imposing speed restrictions. SEPTA is expecting issues.
Some schools already were planning for multiple-day closings, as the snow and ice will be accompanied by one of the region’s more impressive cold snaps of the last several years.
» READ MORE: Philadelphia schools will be closed Monday because of snow; others will likely follow
Were it not for the storm, in fact, the cold might be getting headlines.
Wind chills Saturday morning are expected to drop below zero. Sunday’s high of 25 degrees may make it the warmest day of the week.
It is likely that layers of snow and ice will harden into a frozen mass that the January sun won’t be able to do a whole lot about.
As a public service, for now we will hold off on mentioning another potential storm threat.
The latest on the timing of the storm in Philly
While the weather service warning goes into effect 7 p.m. Saturday, flake sightings could hold off until daybreak Sunday, said Alex Staarmann, meteorologist at the weather service’s Mount Holly office.
Snow may accumulate rapidly Sunday morning with temperatures in the teens. Models were suggesting sleet could mix in as soon as early afternoon, said Tom Kines, senior meteorologist with AccuWeather Inc.
Temperatures in the bottom 5,500 feet of the atmosphere are going to remain well below freezing. However, as the coastal storm intensifies, its onshore winds from the northeast are forecast to import warmer air from over the ocean into the upper atmosphere, which would change the snow to sleet and rain.
It’s possible the precipitation will flip back to all snow and accumulate maybe another inch early Monday, Staarmann said. But at that point it would have all the impact of drizzle in the ocean. The mass of snow and ice evidently will be vacationing in Philly for a while.
“It will stick around for a week, maybe two weeks,” Staarmann said.
How much for Philly?
Just how much snow and ice would be on the ground remained unclear Friday. And it’s all but certain the projections are going to change. The weather service was forecasting 8 to 12 inches for the city, and AccuWeather, 6 to 10 inches. For the record, a grand total of 8.1 inches fell all of last season in Philly.
Louis Uccellini, former head of the National Weather Service and one of the nation’s most prominent winter-storm experts, said some later modeling was cutting back on the ice in areas west of the city, suggesting the possibility of higher snow amounts.
“It’s not that we’re getting 2 to 4 [inches],” said Staarmann. “We’re going to get a lot of snow.”
However, some icing was a near certainty throughout the region.
The ice potential for the Philly region
The weather service is predicting a quarter inch of freezing rain, which is probably about the last thing the people at Peco wanted to hear. Freezing rain is a greater threat to power lines and trees than sleet.
Yes, Peco is well aware of the storm and has crews on standby, said spokesperson Candace Womack.
Sleet develops when a partially melted snowflake or rain drop freezes on the way to the ground. It doesn’t accumulate efficiently like snowflakes. Freezing rain is rain that doesn’t turn to ice until it lands on a surface and freezes on contact.
During a winter storm, both hold down snow accumulations. Typically, an inch of liquid precipitation can yield a foot of snow. A similar amount of liquid would yield about 4 inches of sleet.
Both can fall when surface temperatures are well below freezing, if the upper air is warm enough.
A big difference is that sleet bounces off surfaces, but ice gloms onto them, a menace to power lines and tree branches.
An ice storm resulted in over 700,000 Peco outages in 2014, a winter record. In that case, freezing rain came 18 hours after a heavy snowfall.
When will the snow and ice disappear?
The snow and ice are going to be around for as far as the computer models can see. Temperatures may not get above freezing the rest of the month, as NOAA’s Climate Prediction Center has the odds favoring below normal temperatures through Feb. 6.
The U.S. model was indicating another storm threat for around Groundhog Day, a week from Monday, Uccellini said.
Phil might want a pass this year.
