Flash Flood Warning — Chester County, Pennsylvania
Flooding is imminent or already occurring. Move to higher ground immediately — never drive through flooded roads.
Current Status
🌊 Active: Flash Flood Warning
Flash Flood Warning issued August 3 at 4:20AM EDT until August 3 at 7:00AM EDT by NWS Mount Holly NJ
At 420 AM EDT, Doppler radar and automated rain gauges indicated thunderstorms producing heavy rain across the warned area. Between 1.5 and 3 inches of rain have fallen. The expected rainfall rate is 1 to 2 inches in 1 hour. Additional rainfall amounts up to 1 inch are possible in the warned area. Flash flooding is ongoing or expected to begin shortly. HAZARD...Flash flooding caused by thunderstorms. SOURCE...Radar and automated gauges. 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, West Chester, Norristown, Phoenixville, Lansdale, West Norriton, East Norriton, Doylestown, Conshohocken, Hatboro, Ambler and Collegeville. This includes the following highways... Interstate 476 in Pennsylvania between mile markers 9 and 19. Interstate 76 in Pennsylvania between mile markers 327 and 337. Northeast Extension between mil
Effective August 3, 2026 at 4:20 AM ET · Expires August 3, 2026 at 7:00 AM ET
Event Details
Event Type
Flash Flood Warning
Severity
severe
Issued By
NWS Mount Holly NJ
Expires
August 3, 2026 at 7:00 AM ET
Last Checked
1 minute ago
What To Do
📋 Official NWS Guidance
Turn around...don't drown when encountering flooded roads. Most flood deaths occur in vehicles.
Also In Effect For
This same Flash Flood Warning also covers:
Other Active Alerts in Pennsylvania
Flash Flood Warning
Flash Flood Warning
Flash Flood Warning
Flash Flood Warning
Get Flash Flood Warning Alerts for Chester County
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Frequently Asked Questions
What does a Flash Flood Warning mean for Chester County, Pennsylvania?
Flooding is imminent or already occurring. Move to higher ground immediately — never drive through flooded roads.
Is this Flash Flood Warning currently active?
Yes — this alert is active as of our last check (1 minute ago). It's set to expire August 3, 2026 at 7:00 AM ET.
How do I get notified about Flash Flood Warning alerts for Chester County?
Download StormCast free on Google Play and set Chester County, Pennsylvania as one of your monitored locations. StormCast checks the NWS feed continuously and pushes alerts like this directly to your phone — even with the screen off.
What other areas does this alert cover?
This same Flash Flood Warning is also in effect for Delaware County, Bucks County, Montgomery County.