Alert archive / Pennsylvania / Flash Flood Warnings in 2025

Flash Flood Warning 47, NWS Philadelphia/Mount Holly

July 9, 20254 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 9, 2025, 7:47 PM EDT for 4 counties in Pennsylvania. It was in force for 4 hr. 5 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
Jul 9, 2025, 7:47 PM EDT (23:47 UTC)
Expired
Jul 10, 2025, 12:00 AM 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, Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 73 km from the middle of the area, began a volume at 23:47 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

TimeReportWhereRemark
Jul 9, 8:34 PM EDTFLASH FLOOD1 Wsw Bridesburg, PAFlooding on I-95 southbound between Exit 30: COTTMAN AVE/RHAWN ST and Exit 26: BETSY ROSS BR/ARAMINGO AVE. There is a lane restriction.
Jul 9, 8:57 PM EDTFLASH FLOOD1 Wnw Tinicum Twp, PAFlooding on I-95 southbound between Exit 9B/9A: PA 420 - PROSPECT PARK / ESSINGTON and Exit 8: RIDLEY PARK. There is a lane restriction.
Jul 9, 8:58 PM EDTFLASH FLOOD1 Ssw Summerdale, PAThe Frankford Creek went rapidly into flood stage.
Jul 9, 9:25 PM EDTFLASH FLOOD1 Sw Shawmont - Philade, PAFlooding on I-76 eastbound between 1 miles WEST of Exit 338: GREEN LANE/BELMONT AVE and Exit 338: GREEN LANE/BELMONT AVE. There is a lane restriction.
Jul 9, 9:25 PM EDTFLASH FLOOD1 W Manayunk, PAFlooding on I-76 eastbound between 1 miles WEST of Exit 338: GREEN LANE/BELMONT AVE and Exit 338: GREEN LANE/BELMONT AVE. There is a lane restriction.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 11.8 hours before the alert went out and 217 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.

Skew-T log-pSkew-T log-p diagram, Washington/Dulle, VA at 12:00Z on 2025-07-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 647 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 12:00Z on 2025-07-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -8 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
647 J/kg
Mixed-layer CIN
-65 J/kg
Mixed-layer LCL
836 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
-8 m²/s²
0-3 km storm-relative helicity
42 m²/s²
Significant tornado parameter
-0.0
Supercell composite
-0.0

Open this sounding in Storm Lab

The text

As transmitted.

098 
WGUS51 KPHI 092347
FFWPHI
PAC029-045-091-101-100400-
/O.NEW.KPHI.FF.W.0047.250709T2347Z-250710T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
747 PM EDT Wed Jul 9 2025

The National Weather Service in Mount Holly has issued a

* Flash Flood Warning for...
  East Central Chester County in southeastern Pennsylvania...
  Central Delaware County in southeastern Pennsylvania...
  Southeastern Montgomery County in southeastern Pennsylvania...
  Philadelphia County in southeastern Pennsylvania...

* Until midnight EDT tonight.

* At 747 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 0.5 and 1 inch of rain 
  has fallen. The expected rainfall rate is 1 to 3 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.

  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, Yeadon, Conshohocken, Palmyra, Folcroft, 
  Jenkintown, Narberth, National Park, East Lansdowne, Rockledge and 
  Bryn Athyn.

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 3997 7553 4006 7557 4009 7563 4009 7533
      4010 7520 4014 7502 4012 7496 4010 7496
      4006 7498 4005 7497 3998 7507 3996 7513
      3991 7513 3988 7515 3985 7529 3985 7531
      3994 7525 3996 7546 3991 7552 3992 7554

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL RATE...1-3 INCHES IN 1 HOUR

$$

Hoeflich

The office that day

Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 8, 9:52 PM EDTFlood WatchPHIBerks, Bucks, Chester, Delaware, Lehigh, Montgomery and 2 more26 hr
Jul 9, 6:39 PM EDTFlash Flood WarningPHIChester4 hr
Jul 9, 7:18 PM EDTFlash Flood WarningPHIDelaware4 hr
Jul 9, 7:24 PM EDTSevere Thunderstorm WarningPHIChester, Delaware51 min
Jul 9, 7:38 PM EDTFlash Flood WarningPHIDelaware4 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.