Alert archive / Pennsylvania / Flash Flood Warnings in 2025
Flash Flood Warning 20, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood warning at Jun 26, 2025, 6:49 PM EDT for Chester County, Delaware 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
- Jun 26, 2025, 6:49 PM EDT (22:49 UTC)
- Expired
- Jun 26, 2025, 11:00 PM EDT
- In force
- 4 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Flood severity
- None
Counties Chester County, PA, Delaware County, PA
The nearest sounding before it
Washington/Dulle, VA (KIAD), launched 12:00Z, 10.8 hours before the alert went out and 199 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
- 437 J/kg
- Mixed-layer CIN
- -110 J/kg
- Mixed-layer LCL
- 1094 m above ground
- 0-6 km bulk shear
- 3 kt
- 0-1 km storm-relative helicity
- -18 m²/s²
- 0-3 km storm-relative helicity
- 17 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
157
WGUS51 KPHI 262249
FFWPHI
PAC029-045-270300-
/O.NEW.KPHI.FF.W.0020.250626T2249Z-250627T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
649 PM EDT Thu Jun 26 2025
The National Weather Service in Mount Holly has issued a
* Flash Flood Warning for...
Northeastern Chester County in southeastern Pennsylvania...
Central Delaware County in southeastern Pennsylvania...
* Until 1100 PM EDT.
* At 649 PM EDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Between 0.5 and 1 inch of rain
has fallen. 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.
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...
West Chester, Phoenixville, Coatesville, Westtown, Downingtown,
Honey Brook, Elverson, Lionville, Lionville-Marchwood, Chester
Springs, Pughtown and Glenmoore.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around...don't drown when encountering flooded roads. Most
flood deaths occur in vehicles.
Be aware of your surroundings and do not drive on flooded roads.
&&
LAT...LON 4005 7593 4010 7594 4014 7587 4024 7570
4024 7566 4014 7551 4013 7550 4012 7547
4011 7547 4009 7546 4009 7543 4006 7539
3999 7544 3988 7559
FLASH FLOOD...RADAR INDICATED
$$
Fitzsimmons2 follow-up statements
340
WGUS71 KPHI 262354
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
754 PM EDT Thu Jun 26 2025
PAC029-045-270300-
/O.CON.KPHI.FF.W.0020.000000T0000Z-250627T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Chester PA-Delaware PA-
754 PM EDT Thu Jun 26 2025
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 11 PM EDT THIS
EVENING FOR NORTHEASTERN CHESTER AND CENTRAL DELAWARE COUNTIES...
At 754 PM EDT, Doppler radar indicated that thunderstorms produced
the heaviest rain had left the warned area. Between 0.5 and 1.5
inches of rain have fallen. However, additional showers could result
in rainfall amounts up to 0.5 inches in the warned area. Flash
flooding is ongoing or expected to begin shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar.
IMPACT...Flooding of small creeks and streams, urban areas,
highways, streets, and underpasses as well as other
drainage and low lying areas.
Some locations that may experience flash flooding include...
West Chester, Phoenixville, Coatesville, Westtown, Downingtown,
Honey Brook, Elverson, Lionville, Lionville-Marchwood, Chester
Springs, Pughtown and Glenmoore.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Be especially cautious at night when it is harder to recognize the
dangers of flooding.
&&
LAT...LON 4005 7593 4010 7594 4014 7587 4024 7570
4024 7566 4014 7551 4013 7550 4012 7547
4011 7547 4009 7546 4009 7543 4006 7539
3999 7544 3988 7559
FLASH FLOOD...RADAR INDICATED
$$
SFJ973
WGUS71 KPHI 270255
FFSPHI
Flash Flood Statement
National Weather Service Mount Holly NJ
1055 PM EDT Thu Jun 26 2025
PAC029-045-270305-
/O.EXP.KPHI.FF.W.0020.000000T0000Z-250627T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Chester PA-Delaware PA-
1055 PM EDT Thu Jun 26 2025
...FLASH FLOOD WARNING WILL EXPIRE AT 11 PM EDT THIS EVENING FOR
NORTHEASTERN CHESTER AND CENTRAL DELAWARE COUNTIES...
The heavy rain has ended. Flash flooding is no longer expected to
pose a threat. Rivers may continue to rise as runoff continues.
Please continue to heed remaining road closures.
A Flood Watch remains in effect until 1200 AM EDT for portions of
east central and southeast Pennsylvania.
&&
LAT...LON 4005 7593 4010 7594 4014 7587 4024 7570
4024 7566 4014 7551 4013 7550 4012 7547
4011 7547 4009 7546 4009 7543 4006 7539
3999 7544 3988 7559
$$
AKLThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 26, 12:24 PM EDT | Flood Watch | PHI | Berks, Carbon, Chester, Lehigh | 11 hr |
| Jun 26, 3:48 PM EDT | Severe Thunderstorm Warning | PHI | Berks, Lehigh | 42 min |
| Jun 26, 4:20 PM EDT | Severe Thunderstorm Warning | PHI | Carbon, Lehigh, Monroe, Northampton | 40 min |
| Jun 26, 4:31 PM EDT | Severe Thunderstorm Warning | PHI | Berks, Bucks, Lehigh, Montgomery | 44 min |
| Jun 26, 5:45 PM EDT | Severe Thunderstorm Warning | PHI | Berks, Chester, Montgomery | 45 min |
| Jun 26, 6:21 PM EDT | Flash Flood Warning | PHI | Berks | 2 hr |
| Jun 26, 6:29 PM EDT | Severe Thunderstorm Warning | PHI | Berks, Chester, Delaware, Montgomery | 46 min |
| Jun 26, 6:54 PM EDT | Severe Thunderstorm Warning | PHI | Chester | 36 min |
| Jun 26, 7:14 PM EDT | Severe Thunderstorm Warning | PHI | Chester, Delaware | 46 min |
| Jun 26, 7:27 PM EDT | Flash Flood Warning | PHI | Chester, Delaware | 4 hr |
Nearby
Flash Flood Warnings in Pennsylvania, 2025Every flash flood warning in 2025
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.