Alert archive / New Jersey / Flash Flood Warnings in 2025

Flash Flood Warning 14, NWS Philadelphia/Mount Holly

May 30, 2025Gloucester County, Salem County, New Jersey; Chester County, Delaware County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at May 30, 2025, 11:12 PM EDT for Gloucester County, Salem County, New Jersey; Chester County, Delaware County, 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
May 30, 2025, 11:12 PM EDT (03:12 UTC)
Expired
May 31, 2025, 2:21 AM EDT
In force
3 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

Counties Gloucester County, NJ, Salem County, NJ, Chester County, PA, Delaware County, PA

The radar

The Philadelphia radar (KDIX), 102 km from the middle of the area, began a volume at 03:15 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
May 31, 12:05 AM EDTFLASH FLOODUpland, PAThree lanes flooded on I-95 at Exit 4 near Chester and the Commodore Barry Bridge. Time estimated.

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 00:00Z, 3.2 hours before the alert went out and 182 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 00:00Z on 2025-05-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 926 joules per kilogram.LCLEL10008507005003002001001 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 00:00Z on 2025-05-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 128 square meters per square second.19395878Sfc1 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
926 J/kg
Mixed-layer CIN
-4 J/kg
Mixed-layer LCL
804 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
128 m²/s²
0-3 km storm-relative helicity
146 m²/s²
Significant tornado parameter
0.6
Supercell composite
5.5

Open this sounding in Storm Lab

The text

As transmitted.

771 
WGUS51 KPHI 310312
FFWPHI
NJC015-033-PAC029-045-310715-
/O.NEW.KPHI.FF.W.0014.250531T0312Z-250531T0715Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
1112 PM EDT Fri May 30 2025

The National Weather Service in Mount Holly has issued a

* Flash Flood Warning for...
  Northwestern Gloucester County in southern New Jersey...
  Northwestern Salem County in southern New Jersey...
  Southeastern Chester County in southeastern Pennsylvania...
  Southern Delaware County in southeastern Pennsylvania...

* Until 315 AM EDT.

* At 1112 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Up to 0.5 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.

  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...
  Chester, West Deptford, Pennsville, Westtown, Carneys Point, 
  Folcroft, Swarthmore, Paulsboro, Kennett Square, Penns Grove and 
  West Grove.

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 3987 7588 3991 7585 3994 7567 3994 7539
      3992 7533 3983 7519 3978 7518 3965 7546
      3965 7553 3972 7551 3971 7548 3977 7546
      3980 7541 3983 7551 3983 7562 3980 7571
      3972 7577 3972 7579 3972 7591 3977 7593

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL RATE...1-2 INCHES IN 1 HOUR

$$

Hoeflich
2 follow-up statements
721 
WGUS71 KPHI 310436
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
1236 AM EDT Sat May 31 2025

NJC015-033-PAC029-045-310715-
/O.CON.KPHI.FF.W.0014.000000T0000Z-250531T0715Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Gloucester NJ-Salem NJ-Chester PA-Delaware PA-
1236 AM EDT Sat May 31 2025

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 315 AM EDT EARLY THIS 
MORNING FOR NORTHWESTERN GLOUCESTER, NORTHWESTERN SALEM, 
SOUTHEASTERN CHESTER AND SOUTHERN DELAWARE COUNTIES...

At 1236 AM EDT, trained weather spotters reported thunderstorms 
producing heavy rain along I-95 in Delaware County, with 3 lanes 
flooded at Exit 4 near Chester and the Commodore Barry Bridge. 
Between 1 and 1.5 inches of rain have fallen. The expected rainfall 
rate is 0.5 inches in 1 hour. Additional rainfall amounts of 0.5 to 
1 inch are possible in the warned area. Flash flooding is already 
occurring.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Trained spotters reported.

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...
  Wilmington, Chester, West Deptford, Pennsville, Westtown, Carneys 
  Point, Folcroft, Swarthmore, Paulsboro, Kennett Square, Penns 
  Grove and West Grove.

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 3987 7588 3991 7585 3994 7567 3994 7539
      3992 7533 3983 7519 3978 7518 3965 7546
      3965 7553 3972 7551 3971 7548 3977 7546
      3980 7541 3983 7551 3983 7562 3980 7571
      3972 7577 3972 7579 3972 7591 3977 7593

FLASH FLOOD...OBSERVED
EXPECTED RAINFALL RATE...0.5 INCHES IN 1 HOUR

$$

Hoeflich
025 
WGUS71 KPHI 310621 RRA
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
221 AM EDT Sat May 31 2025

NJC015-033-PAC029-045-310631-
/O.CAN.KPHI.FF.W.0014.000000T0000Z-250531T0715Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Gloucester NJ-Salem NJ-Chester PA-Delaware PA-
221 AM EDT Sat May 31 2025

...FLASH FLOOD WARNING IS CANCELLED FOR NORTHWESTERN GLOUCESTER, 
NORTHWESTERN SALEM, SOUTHEASTERN CHESTER AND SOUTHERN 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 800 AM EDT for portions of 
northern Delaware and Pennsylvania.

A Flood Watch remains in effect until 800 AM EDT for portions of 
central, northern, northwest, and southern New Jersey.

&&

LAT...LON 3987 7588 3991 7585 3994 7567 3994 7539
      3992 7533 3983 7519 3978 7518 3965 7546
      3965 7553 3972 7551 3971 7548 3977 7546
      3980 7541 3983 7551 3983 7562 3980 7571
      3972 7577 3972 7579 3972 7591 3977 7593

$$

Hoeflich

The office that day

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

IssuedProductOfficeCountiesLasted
May 30, 9:04 PM EDTWind AdvisoryPHIAtlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and 2 more10 hr
May 30, 11:36 PM EDTFlash Flood WarningPHIBurlington, Camden, Gloucester4 hr
May 31, 12:34 AM EDTFlash Flood WarningPHIBurlington, Mercer3 hr
May 31, 4:00 AM EDTAreal Flood WarningPHIMorris, Sussex, Warren9 hr
May 31, 4:19 AM EDTAreal Flood WarningPHIHunterdon6 hr
May 31, 5:13 AM EDTAreal Flood WarningPHISomerset97 min
May 31, 8:46 AM EDTAreal Flood WarningPHISomerset7 hr
May 31, 2:12 PM EDTSpecial Marine WarningPHI63 min
May 31, 3:10 PM EDTSpecial Marine WarningPHI65 min
May 31, 3:14 PM EDTSevere Thunderstorm WarningPHICape May16 min
May 31, 4:51 PM EDTSpecial Marine WarningPHI84 min
May 31, 5:04 PM EDTSevere Thunderstorm WarningPHICumberland, Gloucester, Salem41 min
May 31, 6:20 PM EDTRiver Flood WarningPHIMorris12 hr
May 31, 1:04 AM EDTFlash Flood WarningPHIBerks, Bucks, Lehigh, Montgomery4 hr
May 31, 5:06 AM EDTAreal Flood WarningPHILehigh, Montgomery5 hr
May 31, 8:42 AM EDTAreal Flood WarningPHILehigh4 hr

Nearby

Flash Flood Warnings in New Jersey, 2025Flash 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.