Severe thunderstorms capable of damaging winds, large hail and an isolated tornado could hit Lower Merion Township on Wednesday evening, the National Weather Service warned.
The NWS Storm Prediction Center placed Southeast Pennsylvania under a Slight Risk, Level 2 out of 5, for severe weather on Wednesday, Sept. 2. Storms could produce wind gusts of 58 mph or higher and hail 1 inch or larger, according to Patch.
NBC10 Philadelphia meteorologist Bill Henley said the heaviest weather would likely move through between 9 p.m. Wednesday and 3 a.m. Thursday, with damaging wind and heavy rainfall leading to flash flooding as the main threats.
NBC10 issued a First Alert for all of its coverage neighborhoods.
The storms follow a rough Tuesday across the region. Wind gusts reached 70 mph in parts of Pennsylvania, Delaware and New Jersey, knocking out power to more than 65,000 customers and triggering flash flood warnings in eastern Pennsylvania, FOX Weather reported. FOX Weather noted this is likely the first time areas like Philadelphia have been under a Level 2 storm threat for three consecutive days in September since 2023.
The NWS said Wednesday that the severe thunderstorm risk remained highly conditional and that severe storms could continue into Thursday.
Heat advisory Thursday
After the storms pass, heat takes over. The NWS office in Mount Holly, N.J., issued a Heat Advisory for Eastern Montgomery County from 11 a.m. to 8 p.m. Thursday, Sept. 3. Heat index values could reach 101 degrees.
The advisory also covers Delaware County, Lower Bucks County and Philadelphia County. Thursday's high is forecast near 92 degrees.
The NWS warned that hot temperatures combined with high humidity may cause heat illnesses. The agency urged residents to drink plenty of fluids, stay in air-conditioned spaces, stay out of the sun and check on relatives and neighbors. Anyone working outdoors should schedule frequent rest breaks in shaded or cooled areas, the NWS said. The agency warned that heat stroke is a medical emergency and urged residents to call 911 if someone is overcome by heat.
Weekend outlook
No Lower Merion Township-specific cooling center locations were available as of Wednesday afternoon. Residents can contact the township or check the Montgomery County emergency management website for resources.
Conditions are expected to improve by Saturday, with sunny skies and a high near 82 degrees. The Labor Day weekend forecast calls for mostly dry weather.
