Pennsylvania Severe Flash Flood Warning | Effective 07/11/2026 12:31

Headline: 
Flash Flood Warning issued July 11 at 3:31PM EDT until July 11 at 6:45PM EDT by NWS Mount Holly NJ
Event: 
Flash Flood Warning
Urgency: 
Immediate
Effective: 
July 11, 2026 - 12:31pm
Expires: 
July 11, 2026 - 3:45pm
Description: 
At 331 PM EDT, emergency management reported flash flooding occurring in Lower Merion. Between 1.0 and 2.0 inches of rain have fallen, and it fell in about 30 minutes. Although the heaviest rainfall has moved east, flooding continues. There are reports of water assists and rescues. Do not drive through flooded roadways. Additional thunderstorms are possible this afternoon. HAZARD...Flash flooding caused by thunderstorms. SOURCE...Radar. IMPACT...Flooding of small creeks and streams, urban areas, highways, streets, and underpasses as well as other drainage and low lying areas. Some locations that may experience flash flooding include... Philadelphia, Camden, Norristown, Phoenixville, West Norriton, East Norriton, Yeadon, Conshohocken, Folcroft, Narberth, National Park and East Lansdowne. People attending Lemon Hill should seek shelter immediately. This includes the following highways... Interstate 476 in Pennsylvania between mile markers 5 and 19. Interstate 76 in Pennsylvania between mile markers 327 and 351. Interstate 95 in Pennsylvania between mile markers 11 and 29. Interstate 676 in Pennsylvania between mile markers 0 and 1. Northeast Extension between mile markers 21 and 24. Pennsylvania Turnpike between mile markers 321 and 337.
Instruction: 
Turn around...don't drown when encountering flooded roads. Most flood deaths occur in vehicles.
Area Description: 
Chester, PA; Delaware, PA; Montgomery, PA; Philadelphia, PA
Forcast Office: 
NWS Mount Holly NJ