Category: Weather

The first measurable snowfall of the winter of 2025-26 evidently is all but a done deal for Philly this weekend, and it has a chance to be the biggest in two winters — not that the bar is ultra-high in a period when snow has been mightily lacking.

The National Weather Service has issued a winter storm warning for 3 to 5 inches of snow across the region, with a near 100% likelihood of at least an inch of snow.

That was in line with the AccuWeather Inc. outlook.

The weather service has a 76% chance of at least 4 inches and 43% of 6 or more.

With the caveat that timing and duration of precipitation aren’t in the wheelhouse of atmospheric science, the weather service is expecting snow or snow mixed with rain to start late Saturday night.

If it’s a mix at the outset it would quickly become all snow as temperatures fall below freezing, and continue into midmorning.

The snow would be generated primarily by an upper-air disturbance, said Matt Benz, senior meteorologist for AccuWeather. It’s possible that the storm may regroup off the coast, however, that “probably will form too late to have any impact.”

In a forecast discussion, the weather service said inch-an-hour snowfall rates are possible early Sunday.

“There is a potential for a concentrated area of 4-5 inches of snowfall somewhere near the I-95 corridor and immediately south and east,” the forecasters said.

They noted a 20% to 30% chance that some places get over 5 inches.

And the snow is likely to stick around until at least midweek, with high temperatures Sunday, Monday, and Tuesday expected to be around freezing or lower and the sun angles about as low as they get.

After that February storm, the temperature climbed to near 50 a day later, and the strengthening sun made quick work of the snow cover.

That February snow turned out to be the biggest of a season in which the 8.1-inch total at Philadelphia International Airport barely bested the 8 inches of New Orleans. That winter, the I-95 corridor found itself in a snow hole, and Philly a snow hole within a snow hole. The highest total in the winter of 2023-24 was 4.6 inches during a snowy January week.

Snow fell to the north, west, and south, and that trend has continued in the early going. With 6 inches so far this winter, Richmond, Va., now has measured 22.8 inches since last December, nearly triple the Philly total.

Official totals at Philadelphia International Airport have been less than half of normal for four consecutive winters. The normal for a season is 23.2 inches.

The meteorological winter, which began Dec. 1, certainly is off to a wintry start, with temperatures averaging more than 6 degrees below normal.

It is not off to a particularly wet start, however, and whatever falls this weekend isn’t expected to exceed a half inch of liquid.

In its long-term outlooks through Dec. 26, NOAA’s Climate Prediction Center is on the fence regarding whether precipitation will be above or below normal.

With high confidence it is calling for a national warm-up.

In any given year, the odds are greatly against Christmas snow in Philly or elsewhere along the I-95 corridor.

But it does look like the region is about get a white Sunday.

The city experienced its coldest morning since at least Feb. 19 with low temperatures in the teens, even at Philadelphia International Airport, as for the second straight year December is off to quite a chilly start.

And also for the second straight year, those looking forward to that first generous coating of white in Philly, or viewing the possibility with a certain trepidation, may be in for a wait.

Readings dropped into single digits in Pottstown and Doylestown, and in the teens elsewhere. As usual, Philadelphia International Airport was the regional hotspot, bottoming out at 18.

Temperatures are due to top out in the mid-30s Tuesday, more than 10 degrees below normal. A midweek warmup is due as rain approaches, followed by a late-week cooldown, and a deeper chill over the weekend into next week as the Arctic continues to share a generous supply of cold air to the central and eastern United States.

Flake sightings are possible this week in Philly, but don’t expect a rash of school closings.

The city and areas to the north and west may see a few snowflakes at the onset of general rainfall Wednesday, said Robert Deal, the science and operations officer at the National Weather Service Office in Mount Holly. And a dusting or less is possible in the region Friday with a cold frontal passage, he said.

So, while folks around Doylestown had to dig out from a whole three-tenths of an inch of snow during the weekend, and the likes of Atglen, Chester County, and Avalon at the Shore were buried under a tenth of an inch, the vigil goes on for Philly’s first ruler-worth snowfall.

With an unusual degree of certainty, in its Monday update, NOAA’s Climate Prediction Center said it was very likely that temperatures in Philadelphia and the rest of the Northeast would be below normal in the Dec. 13-17 period, with odds favoring below-normal readings through the solstice.

That doesn’t mean it’s going to snow.

Snow has been wanting the last several winters

The region is accustomed to snow snubs.

Deal pointed out that since the 2019-20 season, Philly’s official snowfall is more than 80 inches below normal — that’s a total of 56.7 inches measured, vs. 139.4 inches that constitute the normal.

The last several winters generally have been mild, but snow doesn’t always correlate well with cold, and atmospheric scientists caution that snow is a lousy climate indictor.

Last season, for example, the Dec. 1-Feb. 28 meteorological winter finished about a degree below normal with plenty of cold air for snow, but snowfall was a paltry 8.1 inches — beating New Orleans by a mere 0.1 inches. The seasonal normal as measured at Philadelphia International Airport is 22.3 inches.

Tuesday officially would be Philadelphia’s 13th consecutive day of below-normal temperatures, and 13th without measurable snow.

Why the absence?

Snow around here typically falls near the battlegrounds of cold, heavy air from the north country and warmer moist air off the Gulf and Atlantic Ocean, which can rout the cold.

“We generally need a high-pressure system anchored to the north so it keeps the cold air locked in place,” Deal said. “Lately, most of the high-pressure systems have been more transient, shifting offshore.”

If they are too strong and persistent, those same cold high-pressure systems can repel moisture.

The climate center outlooks favor below-normal precipitation in the Northeast in the six-to-10-day and eight-to-14-day periods.

The lack of snow to date is by no means unusual, Deal points out. On average Philly doesn’t measure an official inch until Dec. 10.

“Right now,” he said, “normal is next to nothing.”

Brightening prospects

The winter solstice doesn’t occur until Dec. 21, but if you have had it with these early sunsets, your prospects are brightening considerably.

Monday’s sunset, just before 4:37 p.m., was a second later than Sunday’s. Tuesday’s will be 4 seconds later than Monday’s, and the sun will call it a day four whole minutes later on Dec. 21.

That will still be the shortest day, however, since daybreak will be later, but feel free to sleep through it.