Philadelphia temperatures might make a run at 100 degrees next week
Philly hasn't reached 100 degrees in 12 years, the longest 100-degree-less stretch in over a century.
After what’s forecast to be a splendid final weekend of the astronomical spring, get ready for that Philadelphia summer tradition — a heat wave.
A marinade of heat and atmospheric moisture, which we commonly call humidity, is expected to make conditions progressively more uncomfortable as temperatures rise.
Said Tyler Roys, senior meteorologist with AccuWeather Inc, “There’s a chance we make a run at 100.” The last time that happened was in 2012, the city’s longest 100-degree-less stretch in over a century.
Fittingly, that could occur on Thursday, Roys said, when summer officially arrives.
On Friday, an advancing cold front set off a potent thunderstorm that resulted in flooding in parts of the region and about 25,000 power outages, but by this time next week, the Philly region and much of the East might welcome a few thunderstorms.
Forecasters are calling for a several-day run of 90 or better temperatures in Philly, and NOAA’s Climate Prediction Center forecast strongly favors above-normal temperatures for the next two weeks.
You may have noticed that the ground is beginning to harden as rain deficits have been growing. That dryness may contribute to the building heat, and heat is known to beget heat.
The first heat wave of the year will be a “sucker-punch,” Roys said.
Even though temperatures have been above average this month, the coming hot spell might be particularly challenging to the body, said Laurence Kalkstein, a climatologist who is an expert on heat-related mortality.
“Very hot weather early in the season is more dangerous than later in the season,” he said.
In the short term, the atmosphere should be a welcoming place this weekend with sun, highs in the 80s and comfortable nights, thanks to the cold front that crossed the region Friday.
Here’s what’s brewing in Philly’s air, and on the ground
The weekend pleasantness evidently will be short-lived. Rain- and cloud-discouraging high pressure, or heavier air, will build next week over the East, allowing the sun to bake the ground.
Even when the ground is dry, however, the Philly region is prone to sultriness, being in proximity of major bodies of water that are copious producers of steamy air.
Philly’s temperatures have been rising, but heat waves haven’t rivaled the deadly, long-duration hot spells of the 1990s. During an 11-day heat wave in July 1993, the temperature reached 100 degrees on three consecutive days. It hit 100 again during a 24-day hot spell in 1995.
Just like AccuWeather, the weather service is calling for highs in the 90s Tuesday, Wednesday, and Thursday, with a 90 possible on Monday.
The agency said it will wait and see on any heat warnings, but says the potential “will only grow with time as the week progresses.”
Roys said it’s possible that Philly may make a run at the record high temperature for the date on Thursday, 98 degrees, set in 1931 in the Dust Bowl era.
Summer arrives that day at 4:50 p.m.
By then, that will be an astronomical technicality.