Relief from the heat arrives in slow motion, with severe storms possible
- Relief from the heat will be slow to arrive in the Lehigh Valley
- Severe storms are possible Thursday and Friday
- The weekend also is likely to feature locally heavy rainfall
BETHLEHEM, Pa. — The dry, scorching start to September will slowly begin to ease Thursday as severe weather takes aim at the Lehigh Valley.
“It looks like rain and storms will be returning over the next several days,” EPAWA meteorologist Bobby Martrich said in his latest video update.
It comes as unseasonably warm air continues to extend up the East Coast, bringing three straight days with highs above 90 degrees to the area thus far.
Even as the heat begins to erode, maximum temperatures again are forecast to reach the lower to middle 90s on Thursday — making for our longest run of 90-degree days in 2023.
Dew point readings also are forecast to stay in the upper 60s to lower 70s and heat index values near or in excess of 100 degrees, with the highest values along the Interstate 95 corridor and points to the southeast.
“We haven’t had any rain, really of note, so far in September,” Martrich said. “Most areas are about three quarters of an inch behind average already for the month.”
But that will begin to change Thursday and Friday, with a severe weather outlook from the Storm Prediction Center warning of frequent cloud to ground lightning and damaging wind gusts possible.
Timing for the storms will be in the afternoon and evening both days.
“It’s not going to be absolutely everywhere,” Martrich said. “I think it’s mostly going to be an interior threat.”
Martrich also said there would be no tornado threat and no hail threat with any storms, while noting the potential for “gusty straight-line winds and locally heavy rainfall.”
He said some straight-line winds could be 40 to 50 mph, with a few “rogue” storms where winds could be stronger.
While the hot/humid conditions continue today & Friday, we now introduce the chance for some showers & t-storms this PM & Friday PM. Some storms could become severe with locally damaging wind gusts. Be weather aware! Local forecasts https://t.co/ka2HFv1KuB #pawx #njwx #dewx #mdwx pic.twitter.com/JZSCQv9yho— NWS Mount Holly (@NWS_MountHolly) September 7, 2023
A weekend washout?
There may be a repeat performance of storms on Saturday, the National Weather Service warns, with precipitable water values in the 1.5 to 2 inch range and locally heavy rainfall possible.
“We certainly can use the rain,” the NWS forecast discussion said, while noting the overall flash flood risk may be more limited unless training of storms occurs.
Locally heavy rain will also be “probable” again on Sunday.