A severe thunderstorm watch is up for Philly on Tuesday as the flood threat continues
After a wet week, the atmosphere will remain juiced the next few days.
While the downpours on Monday spared most of the region, forecasters warned that the rainforest conditions are not going anywhere and that strong thunderstorms are possible Tuesday.
NOAA’s Storm Prediction Center has issued a severe storm watch until 9 p.m. for cells that could generate gusts up to 60 mph.
A flash flood watch is in effect until midnight Tuesday, and the rest of the week isn’t looking a whole lot better.
Or the weekend.
The capricious rains on Monday doused the Oxford and Parkesburg areas of southwestern Chester County with as much as 4 inches of rain, setting off flash flooding, the National Weather Service said.
Fortunately for the rest of the region — and flooding would be about the last thing Philadelphia would need during a trash strike — the pulse of moisture rained “itself out,” said Bob Larson, senior meteorologist with AccuWeather Inc.
The rain was associated with the remnants of what the National Hurricane Center called “post-tropical cyclone” Chantal, which was about to exit off the New Jersey coast in a diminished state.
However, “a lot of juice” remains in the air over Philly, Larson said.
And the vaporous atmospheric soup seems determined to stick around for a few days, said Mike Silva, meteorologist with the National Weather Service in Mount Holly.
The heat advisory continues into Tuesday, which is expected to be a shade warmer and a heat index higher.
Then, more showers are expected as a front approaches, and Larson said he would be surprised if the National Oceanic and Atmospheric Administration‘s Storm Prediction Center doesn’t post a severe thunderstorm watch.
“Here we go again,” Larson said.
How bad were Monday’s storms in Chester County?
The weather service posted numerous reports of road closings around Oxford and Parkesburg between 2:30 and 4 p.m. Monday.
The West Branch Big Elk Creek sloshed over its banks, and roadway flooding was occurring in Oxford, with at least one water rescue on Route 1, the weather service said. Floods shut down Reedville Road, near Lincoln University.
The weather service said that rain amounts of 2.5 to 4 inches were reported during the downpours.
With thunderstorms in the area, Philadelphia International Airport said that some arriving flights were being delayed an average of 55 minutes.
What is the outlook for the rest of the week?
Larson put it this way: Wednesday is looking like the nicest day of the week, “and it’s not going to be nice.”
He said that the approaching front that will trigger the potentially strong storms Tuesday isn’t exactly a powerhouse and isn’t going to clear right away.
Larson said Wednesday should be slightly less humid — from “very humid to plain old humid” — probably not enough of change to be noticeable, and showers are again possible.
This has been quite a wet period in the Philly region
In light of the recent wetness, the potential cumulative effects of the rains are of some concern, said the weather service’s Silva.
According to the weather service’s Middle Atlantic River Forecast Center, rain totals last week ranged from 1.5 to 2.7 inches across the region, with totals in Burlington and Chester Counties more than 250% of normal. The center uses a sampling of stations to calculate countywide totals.
“The impacts could kind of build upon themselves,” he said.
Silva pointed out that the catastrophic flooding associated with Hurricane Ida had a whole lot to do with antecedent rains.
Within two weeks of Ida’s arrival in September 2021, the remnants of Tropical Storms Fred and Henri had wrung out prodigious amounts of rain in the region, with some areas reporting amounts of 5-plus inches from each storm.
“Everything was saturated,” he said, “so there was really no place for the rains to go.”
Chantal was no Ida, and on Monday, at least, most of the region got off easy.