Alert archive / Pennsylvania / Flash Flood Warnings in 2026
Flash Flood Warning 89, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 3, 2026, 3:01 AM EDT for 4 counties in Pennsylvania. It was in force for 3 hr. 3 reports came from inside the area while it was in force.
The area
The outline as issued, with what was reported inside it.
The facts
- Issued
- Aug 3, 2026, 3:01 AM EDT (07:01 UTC)
- Expired
- Aug 3, 2026, 6:26 AM EDT
- In force
- 3 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Flood severity
- None
Counties Bucks County, PA, Chester County, PA, Delaware County, PA, Montgomery County, PA
The radar
The Philadelphia radar (KDIX), 73 km from the middle of the area, began a volume at 07:03 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Aug 3, 3:50 AM EDT | FLASH FLOOD | 1 N Hatboro, PA | Water rescue due to a car stranded in flood water at the intersection of Bright Road and Blair Mill Road. Time from report. |
| Aug 3, 5:54 AM EDT | FLASH FLOOD | 1 Wsw King Of Prussia, PA | Flooding on I-76 eastbound at Exit 328: US 202 SOUTH - WEST CHESTER TO US 422 WEST. Ramp restriction. |
| Aug 3, 6:30 AM EDT | FLASH FLOOD | 2 Nnw Bryn Athyn, PA | Masons Mill Road closed due to flooding. Time from report. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Brookhaven, NY (KOKX), launched 00:00Z, 7.0 hours before the alert went out and 213 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 151 J/kg
- Mixed-layer CIN
- -2 J/kg
- Mixed-layer LCL
- 507 m above ground
- 0-6 km bulk shear
- 38 kt
- 0-1 km storm-relative helicity
- 163 m²/s²
- 0-3 km storm-relative helicity
- 198 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 1.7
The text
As transmitted.
506
WGUS51 KPHI 030701
FFWPHI
PAC017-029-045-091-031100-
/O.NEW.KPHI.FF.W.0089.260803T0701Z-260803T1100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
301 AM EDT Mon Aug 3 2026
The National Weather Service in Mount Holly has issued a
* Flash Flood Warning for...
Central Bucks County in southeastern Pennsylvania...
Northeastern Chester County in southeastern Pennsylvania...
Northeastern Delaware County in southeastern Pennsylvania...
Central Montgomery County in southeastern Pennsylvania...
* Until 700 AM EDT.
* At 301 AM EDT, Doppler radar and automated rain gauges indicated
thunderstorms producing heavy rain across the warned area. Between
0.5 and 1.5 inches of rain have fallen. The expected rainfall rate
is 1 to 2 inches in 1 hour. Additional rainfall amounts of 1 to 2
inches 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 mile markers 21 and 31.
Pennsylvania Turnpike between mile markers 312 and 346.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around...don't drown when encountering flooded roads. Most
flood deaths occur in vehicles.
&&
LAT...LON 4012 7569 4041 7505 4040 7503 4041 7499
4040 7497 4034 7494 4029 7487 4008 7517
4007 7519 4009 7523 4005 7526 4003 7523
3998 7531 3992 7565
FLASH FLOOD...RADAR AND GAUGE INDICATED
EXPECTED RAINFALL RATE...1-2 INCHES IN 1 HOUR
$$
Cooper3 follow-up statements
524
WGUS71 KPHI 030820
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
420 AM EDT Mon Aug 3 2026
PAC017-029-045-091-031100-
/O.CON.KPHI.FF.W.0089.000000T0000Z-260803T1100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Bucks PA-Chester PA-Delaware PA-Montgomery PA-
420 AM EDT Mon Aug 3 2026
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 7 AM EDT THIS MORNING
FOR CENTRAL BUCKS, NORTHEASTERN CHESTER, NORTHEASTERN DELAWARE AND
CENTRAL MONTGOMERY COUNTIES...
At 420 AM EDT, Doppler radar and automated rain gauges indicated
thunderstorms producing heavy rain across the warned area. Between
1.5 and 3 inches of rain have fallen. The expected rainfall rate is
1 to 2 inches in 1 hour. Additional rainfall amounts up to 1 inch
are possible in the warned area. Flash flooding is ongoing or
expected to begin shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar and automated gauges.
IMPACT...Flooding of small creeks and streams, urban areas,
highways, streets, and underpasses as well as other
drainage and low lying areas.
Some locations that may experience flash flooding include...
Philadelphia, West Chester, Norristown, Phoenixville, Lansdale,
West Norriton, East Norriton, Doylestown, Conshohocken, Hatboro,
Ambler and Collegeville.
This includes the following highways...
Interstate 476 in Pennsylvania between mile markers 9 and 19.
Interstate 76 in Pennsylvania between mile markers 327 and 337.
Northeast Extension between mile markers 21 and 31.
Pennsylvania Turnpike between mile markers 312 and 346.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around...don't drown when encountering flooded roads. Most
flood deaths occur in vehicles.
&&
LAT...LON 4012 7569 4041 7505 4040 7503 4041 7499
4040 7497 4034 7494 4029 7487 4008 7517
4007 7519 4009 7523 4005 7526 4003 7523
3998 7531 3992 7565
FLASH FLOOD...RADAR AND GAUGE INDICATED
EXPECTED RAINFALL RATE...1-2 INCHES IN 1 HOUR
$$
Cooper428
WGUS71 KPHI 030909
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
509 AM EDT Mon Aug 3 2026
PAC029-045-030919-
/O.CAN.KPHI.FF.W.0089.000000T0000Z-260803T1100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Chester PA-Delaware PA-
509 AM EDT Mon Aug 3 2026
...FLASH FLOOD WARNING IS CANCELLED FOR NORTHEASTERN CHESTER AND
NORTHEASTERN DELAWARE COUNTIES...
Flooding is no longer expected to pose a threat. Please continue to
heed remaining road closures.
A Flood Watch remains in effect until 1100 PM EDT Monday for
portions of northern Delaware, New Jersey, and Pennsylvania.
&&
LAT...LON 4040 7497 4034 7494 4029 7487 4008 7517
4007 7519 4009 7523 4005 7526 4003 7523
3999 7529 4007 7537 4006 7539 4010 7542
4009 7546 4011 7547 4012 7546 4013 7550
4016 7550 4015 7552 4017 7554 4041 7505
$$
PAC017-091-031100-
/O.CON.KPHI.FF.W.0089.000000T0000Z-260803T1100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Bucks PA-Montgomery PA-
509 AM EDT Mon Aug 3 2026
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 7 AM EDT THIS MORNING
FOR CENTRAL BUCKS AND CENTRAL MONTGOMERY COUNTIES...
At 509 AM EDT, Doppler radar and automated rain gauges indicated
thunderstorms producing heavy rain across the warned area. Between
1.5 and 3 inches of rain have fallen. Flooding impacts will
continue, but no additional rainfall is expected. Flash flooding is
ongoing or expected to begin shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar and automated gauges.
IMPACT...Flooding of small creeks and streams, urban areas,
highways, streets, and underpasses as well as other
drainage and low lying areas.
Some locations that may experience flash flooding include...
Philadelphia, Norristown, Phoenixville, Lansdale, West Norriton,
East Norriton, Doylestown, Conshohocken, Hatboro, Ambler,
Collegeville and Narberth.
This includes the following highways...
Interstate 476 in Pennsylvania between mile markers 15 and 19.
Interstate 76 in Pennsylvania between mile markers 327 and 337.
Northeast Extension between mile markers 21 and 31.
Pennsylvania Turnpike between mile markers 327 and 346.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around...don't drown when encountering flooded roads. Most
flood deaths occur in vehicles.
&&
LAT...LON 4040 7497 4034 7494 4029 7487 4008 7517
4007 7519 4009 7523 4005 7526 4003 7523
3999 7529 4007 7537 4006 7539 4010 7542
4009 7546 4011 7547 4012 7546 4013 7550
4016 7550 4015 7552 4017 7554 4041 7505
FLASH FLOOD...RADAR AND GAUGE INDICATED
$$
Cooper161
WGUS71 KPHI 031026
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
626 AM EDT Mon Aug 3 2026
PAC017-091-031036-
/O.CAN.KPHI.FF.W.0089.000000T0000Z-260803T1100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Bucks PA-Montgomery PA-
626 AM EDT Mon Aug 3 2026
...FLASH FLOOD WARNING FOR CENTRAL BUCKS AND CENTRAL MONTGOMERY
COUNTIES HAS BEEN REPLACED WITH A FLOOD WARNING...
&&
LAT...LON 4040 7497 4034 7494 4029 7487 4008 7517
4007 7519 4009 7523 4005 7526 4003 7523
3999 7529 4007 7537 4006 7539 4010 7542
4009 7546 4011 7547 4012 7546 4013 7550
4016 7550 4015 7552 4017 7554 4041 7505
$$
DealThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 2, 11:20 PM EDT | Flash Flood Warning | PHI | Berks, Bucks, Lehigh, Montgomery, Northampton | 4 hr |
| Aug 3, 12:05 AM EDT | Flash Flood Warning | PHI | Bucks, Monroe, Northampton | 3 hr |
| Aug 3, 3:05 AM EDT | Severe Thunderstorm Warning | PHI | Bucks, Montgomery | 40 min |
| Aug 3, 4:41 AM EDT | Flash Flood Warning | PHI | Bucks, Delaware, Montgomery, Philadelphia | 2 hr |
| Aug 3, 6:26 AM EDT | Areal Flood Warning | PHI | Bucks, Montgomery | 94 min |
| Aug 3, 7:02 AM EDT | Areal Flood Warning | PHI | Bucks, Delaware, Montgomery, Philadelphia | 3 hr |
| Aug 3, 9:08 AM EDT | Flash Flood Warning | PHI | Bucks, Delaware, Montgomery, Philadelphia | 3 hr |
| Aug 3, 10:36 AM EDT | Flash Flood Warning | PHI | Bucks | 6 hr |
| Aug 3, 10:44 AM EDT | Flash Flood Warning | PHI | Bucks, Philadelphia | 6 hr |
| Aug 3, 12:01 PM EDT | Areal Flood Warning | PHI | Bucks | 74 min |
| Aug 3, 1:20 PM EDT | Areal Flood Warning | PHI | Bucks, Delaware, Montgomery, Philadelphia | 4 hr |
Nearby
Flash Flood Warnings in Pennsylvania, 2026Every flash flood warning in 2026
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.