Alert archive / Pennsylvania / Flash Flood Warnings in 2026
Flash Flood Warning 119, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 17, 2026, 1:57 AM EDT for Bucks County, Montgomery County, Philadelphia County, Pennsylvania. It was in force for 4 hr. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Aug 17, 2026, 1:57 AM EDT (05:57 UTC)
- Expired
- Aug 17, 2026, 5:36 AM EDT
- In force
- 4 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Flood severity
- None
Counties Bucks County, PA, Montgomery County, PA, Philadelphia County, PA
The radar
The Philadelphia radar (KDIX), 69 km from the middle of the area, began a volume at 05:59 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.
The nearest sounding before it
Brookhaven, NY (KOKX), launched 00:00Z, 6.0 hours before the alert went out and 208 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
- 28 J/kg
- Mixed-layer CIN
- -2 J/kg
- Mixed-layer LCL
- 851 m above ground
- 0-6 km bulk shear
- 24 kt
- 0-1 km storm-relative helicity
- 38 m²/s²
- 0-3 km storm-relative helicity
- 63 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
182
WGUS51 KPHI 170557
FFWPHI
PAC017-091-101-171000-
/O.NEW.KPHI.FF.W.0119.260817T0557Z-260817T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
157 AM EDT Mon Aug 17 2026
The National Weather Service in Mount Holly has issued a
* Flash Flood Warning for...
Southern Bucks County in southeastern Pennsylvania...
Central Montgomery County in southeastern Pennsylvania...
Northeastern Philadelphia County in southeastern Pennsylvania...
* Until 600 AM EDT.
* At 157 AM EDT, Doppler radar indicated 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 0.5 to 1.5 inches are possible in the warned
area. Flash flooding is ongoing or expected to begin shortly.
HAZARD...Flash flooding caused by heavy rain.
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, Norristown, Lansdale, West Norriton, East Norriton,
Doylestown, Hatboro, Souderton, Ambler, Collegeville, Jenkintown
and Chalfont.
This includes the following highways...
Northeast Extension between mile markers 21 and 35.
Pennsylvania Turnpike between mile markers 334 and 352.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around...don't drown when encountering flooded roads. Most
flood deaths occur in vehicles.
Be especially cautious at night when it is harder to recognize the
dangers of flooding.
&&
LAT...LON 4023 7482 4016 7484 4007 7514 4008 7518
4021 7556 4022 7559 4035 7532
FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL RATE...1-2 INCHES IN 1 HOUR
$$
Guzzo2 follow-up statements
892
WGUS71 KPHI 170724
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
324 AM EDT Mon Aug 17 2026
PAC017-091-101-171000-
/O.CON.KPHI.FF.W.0119.000000T0000Z-260817T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Bucks PA-Montgomery PA-Philadelphia PA-
324 AM EDT Mon Aug 17 2026
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 6 AM EDT EARLY THIS
MORNING FOR SOUTHERN BUCKS, CENTRAL MONTGOMERY AND NORTHEASTERN
PHILADELPHIA COUNTIES...
At 324 AM EDT, Doppler radar indicated heavy rain across the warned
area. Between 1 and 2 inches of rain have fallen. Additional
rainfall amounts up to 0.5 inches are possible in the warned area.
Flash flooding is ongoing or expected to begin shortly.
HAZARD...Flash flooding caused by heavy rain.
SOURCE...Radar.
IMPACT...Flooding of small creeks and streams, urban areas,
highways, streets, and underpasses as well as other
drainage and low lying areas.
Some locations that may experience flash flooding include...
Philadelphia, Norristown, Lansdale, West Norriton, East Norriton,
Doylestown, Hatboro, Souderton, Ambler, Collegeville, Jenkintown
and Chalfont.
This includes the following highways...
Northeast Extension between mile markers 21 and 35.
Pennsylvania Turnpike between mile markers 334 and 352.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around...don't drown when encountering flooded roads. Most
flood deaths occur in vehicles.
Be especially cautious at night when it is harder to recognize the
dangers of flooding.
&&
LAT...LON 4023 7482 4016 7484 4007 7514 4008 7518
4021 7556 4022 7559 4035 7532
FLASH FLOOD...RADAR INDICATED
$$
Guzzo656
WGUS71 KPHI 170936
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
536 AM EDT Mon Aug 17 2026
PAC017-091-101-170946-
/O.CAN.KPHI.FF.W.0119.000000T0000Z-260817T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Bucks PA-Montgomery PA-Philadelphia PA-
536 AM EDT Mon Aug 17 2026
...FLASH FLOOD WARNING IS CANCELLED FOR SOUTHERN BUCKS, CENTRAL
MONTGOMERY AND NORTHEASTERN PHILADELPHIA COUNTIES...
The heavy rain has ended. Flooding is no longer expected to pose a
threat. Please continue to heed remaining road closures.
&&
LAT...LON 4023 7482 4016 7484 4007 7514 4008 7518
4021 7556 4022 7559 4035 7532
$$
MPSThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 16, 11:21 PM EDT | Flash Flood Warning | PHI | Chester, Delaware, Montgomery, Philadelphia | 4 hr |
| Aug 16, 11:38 PM EDT | Flash Flood Warning | PHI | Bucks, Delaware, Montgomery, Philadelphia | 4 hr |
| Aug 17, 4:43 PM EDT | Special Weather Statement | PHI | Berks | 47 min |
| Aug 17, 5:09 PM EDT | Severe Thunderstorm Warning | PHI | Berks | 36 min |
| Aug 17, 5:30 PM EDT | Special Weather Statement | PHI | Berks | 30 min |
| Aug 17, 6:03 PM EDT | Severe Thunderstorm Warning | PHI | Berks, Chester, Montgomery | 42 min |
| Aug 17, 6:45 PM EDT | Severe Thunderstorm Warning | PHI | Chester, Delaware | 32 min |
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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.