Alert archive / Pennsylvania / Flash Flood Warnings in 2026
Flash Flood Warning 127, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 23, 2026, 3:49 AM EDT for 5 counties in Pennsylvania. It was in force for 3 hr. 1 report 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 23, 2026, 3:49 AM EDT (07:49 UTC)
- Expired
- Aug 23, 2026, 6:29 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, Philadelphia County, PA
The radar
The Philadelphia radar (KDIX), 62 km from the middle of the area, began a volume at 07:49 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 23, 4:12 AM EDT | FLASH FLOOD | 1 Ssw Summerdale, PA | The gauge at Frankford Creek rose above flood stage. It crested at minor flood levels. |
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, 7.8 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
- 5 J/kg
- Mixed-layer CIN
- 0 J/kg
- Mixed-layer LCL
- 531 m above ground
- 0-6 km bulk shear
- 24 kt
- 0-1 km storm-relative helicity
- 14 m²/s²
- 0-3 km storm-relative helicity
- 88 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
772
WGUS51 KPHI 230749
FFWPHI
PAC017-029-045-091-101-231200-
/O.NEW.KPHI.FF.W.0127.260823T0749Z-260823T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
349 AM EDT Sun Aug 23 2026
The National Weather Service in Mount Holly has issued a
* Flash Flood Warning for...
South Central Bucks County in southeastern Pennsylvania...
Eastern Chester County in southeastern Pennsylvania...
Northeastern Delaware County in southeastern Pennsylvania...
Southeastern Montgomery County in southeastern Pennsylvania...
Philadelphia County in southeastern Pennsylvania...
* Until 800 AM EDT.
* At 349 AM EDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Between 1 and 1.5 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.
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, Bensalem, Norristown, Lansdale, West
Norriton, East Norriton, Yeadon, Conshohocken, Palmyra, Hatboro
and Ambler.
This includes the following highways...
Interstate 476 in Pennsylvania between mile markers 7 and 19.
Interstate 76 in Pennsylvania between mile markers 327 and 351.
Interstate 95 in Pennsylvania between mile markers 14 and 37.
Interstate 676 in Pennsylvania between mile markers 0 and 1.
Northeast Extension between mile markers 21 and 25.
Pennsylvania Turnpike between mile markers 326 and 348.
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.
Please report observed flooding to local emergency services or law
enforcement and request they pass this information to the National
Weather Service when you can do so safely.
&&
LAT...LON 4027 7522 4008 7490 4005 7497 4002 7501
4001 7505 3998 7507 3996 7513 3994 7514
3992 7513 3988 7516 3988 7520 4004 7549
FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL RATE...1-2 INCHES IN 1 HOUR
$$
MPS2 follow-up statements
246
WGUS71 KPHI 230907
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
507 AM EDT Sun Aug 23 2026
PAC029-230917-
/O.CAN.KPHI.FF.W.0127.000000T0000Z-260823T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Chester PA-
507 AM EDT Sun Aug 23 2026
...FLASH FLOOD WARNING IS CANCELLED FOR EASTERN CHESTER COUNTY...
Flooding is no longer expected to pose a threat. Please continue to
heed remaining road closures.
&&
LAT...LON 4020 7512 4008 7490 4005 7497 4002 7501
4001 7505 3998 7507 3996 7513 3994 7514
3992 7513 3988 7516 3988 7520 3999 7540
$$
PAC017-045-091-101-231200-
/O.CON.KPHI.FF.W.0127.000000T0000Z-260823T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Bucks PA-Delaware PA-Montgomery PA-Philadelphia PA-
507 AM EDT Sun Aug 23 2026
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 8 AM EDT THIS MORNING
FOR SOUTH CENTRAL BUCKS, NORTHEASTERN DELAWARE, SOUTHEASTERN
MONTGOMERY AND PHILADELPHIA COUNTIES...
At 507 AM EDT, Thunderstorms that produced heavy rain resulted in 1
to 2 inches of rain. While the rain has ended, flash flooding is
ongoing or expected to begin shortly.
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, Bensalem, Yeadon, Palmyra, Hatboro,
Jenkintown, Narberth, National Park, East Lansdowne, Beverly and
Rockledge.
This includes the following highways...
Interstate 476 in Pennsylvania between mile markers 8 and 12.
Interstate 76 in Pennsylvania between mile markers 333 and 351.
Interstate 95 in Pennsylvania between mile markers 15 and 37.
Interstate 676 in Pennsylvania between mile markers 0 and 1.
Pennsylvania Turnpike between mile markers 337 and 347.
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.
Please report observed flooding to local emergency services or law
enforcement and request they pass this information to the National
Weather Service when you can do so safely.
&&
LAT...LON 4020 7512 4008 7490 4005 7497 4002 7501
4001 7505 3998 7507 3996 7513 3994 7514
3992 7513 3988 7516 3988 7520 3999 7540
FLASH FLOOD...RADAR INDICATED
$$
MPS718
WGUS71 KPHI 231029 RRA
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
629 AM EDT Sun Aug 23 2026
PAC017-045-091-101-231039-
/O.CAN.KPHI.FF.W.0127.000000T0000Z-260823T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Bucks PA-Delaware PA-Montgomery PA-Philadelphia PA-
629 AM EDT Sun Aug 23 2026
...FLASH FLOOD WARNING IS CANCELLED FOR SOUTH CENTRAL BUCKS,
NORTHEASTERN DELAWARE, SOUTHEASTERN MONTGOMERY AND PHILADELPHIA
COUNTIES...
Flood waters have receded. The heavy rain has ended. Flooding is no
longer expected to pose a threat. Please continue to heed remaining
road closures.
&&
LAT...LON 4020 7512 4008 7490 4005 7497 4002 7501
4001 7505 3998 7507 3996 7513 3994 7514
3992 7513 3988 7516 3988 7520 3999 7540
$$
MPSThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 23, 3:32 AM EDT | Flash Flood Warning | PHI | Delaware | 3 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.