A potent and rapidly moving thunderstorm that generated winds gusting past 55 mph ripped down trees and wires and quickly knocked out power to more than 275,000 Peco customers late Thursday afternoon.

“This is going to be a multiday restoration effort,” said Peco spokesperson Ben Armstrong.

While no twisters were reported — although the National Weather Service had issued a tornado warning for northern Delaware and part of Delaware County — the storm struck with an impressive ferocity.

Armstrong said the winds were so powerful that they took down not only branches, but whole trees and poles.

Numerous trees were reported downed in Lower Merion Township, and snapped in Bensalem Township, where they fell upon cars. Trees fell into houses in Westtown and East Marlborough Township, Chester County, and Thornton, Delaware County the weather service reported. Tree limbs littered roads in Concord Township, Delaware County.

A gust of 56 mph was measured in Coatesville, the weather service reported.

Armstrong said anyone who comes near downed power lines should “assume they are energized” and call Peco at 1-800-841-4141.

While the entire region remained under a severe thunderstorm watch through 9 p.m., Nick Guzzo, a National Weather Service meteorologist in Mount Holly, said that any additional storms would not be as potent as the one that struck the region between 5 and 6 p.m. “It was an eventful 60 minutes,” said Armstrong.

The storm did its damage in a hurry. “It was really moving fast,” Guzzo said.

The bulk of the damage appeared to occur on the Pennsylvania side of the Delaware River, with Atlantic Electric reporting only about 4,000 outages at 8 p.m.

The mayhem was set off by an approaching front inciting a highly charged and saturated air mass.

On the plus side, it did knock back the heat. At Philadelphia International Airport, it shaved about 20 degrees off the temperature, which peaked at 93 earlier in the afternoon.

In the wake of the front, Friday will be dry and comfortable, forecasters said, with highs in the mid-80s.

But don’t get used to it.

A potentially long-duration heat wave is due to get underway during the weekend.

Temperatures could hit 90 on Saturday, and then assuredly will crest past 90 Sunday and may even approach 100 next week, a mark that Philadelphia has not reached officially since 2012. That is the longest interval between 100-degree readings in the city since the early 1900s.

And the heat wave could extend through the week, said Dave Dombek, senior meteorologist with AccuWeather Inc.

Given how generally temperate it has been the last several weeks, this week’s warm spell notwithstanding, Dombek said: “It’s going to be quite a change.”