Alert archive / New Jersey / Flash Flood Warnings in 2026

Flash Flood Warning 152, NWS Philadelphia/Mount Holly

September 1, 2026Atlantic County, Camden County, Gloucester County, New Jersey

NWS Philadelphia/Mount Holly issued this flash flood warning at Sep 1, 2026, 9:26 PM EDT for Atlantic County, Camden County, Gloucester County, New Jersey. It was in force for 115 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Sep 1, 2026, 9:26 PM EDT (01:26 UTC)
Expired
Sep 1, 2026, 11:21 PM EDT
In force
115 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

Counties Atlantic County, NJ, Camden County, NJ, Gloucester County, NJ

The radar

The Philadelphia radar (KDIX), 50 km from the middle of the area, began a volume at 01:29 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, 1.4 hours before the alert went out and 215 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, Brookhaven, NY at 00:00Z on 2026-09-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 353 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, Brookhaven, NY at 00:00Z on 2026-09-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 66 square meters per square second.1939587897Sfc1 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
353 J/kg
Mixed-layer CIN
-39 J/kg
Mixed-layer LCL
466 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
66 m²/s²
0-3 km storm-relative helicity
141 m²/s²
Significant tornado parameter
-0.1
Supercell composite
-0.8

Open this sounding in Storm Lab

The text

As transmitted.

993 
WGUS51 KPHI 020126
FFWPHI
NJC001-007-015-020530-
/O.NEW.KPHI.FF.W.0152.260902T0126Z-260902T0530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
926 PM EDT Tue Sep 1 2026

The National Weather Service in Mount Holly has issued a

* Flash Flood Warning for...
  Northwestern Atlantic County in southern New Jersey...
  Southeastern Camden County in southern New Jersey...
  Southeastern Gloucester County in southern New Jersey...

* Until 130 AM EDT.

* At 926 PM EDT, Doppler radar indicated thunderstorms producing
  heavy rain. Collings Lakes Fire Department reported multiple roads
  in downtown Williamstown under water. Between 1 and 2 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 already occurring.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Fire department reported.

  IMPACT...Flash flooding of small creeks and streams, urban areas,
           highways, streets and underpasses as well as other poor
           drainage and low-lying areas.

* Some locations that will experience flash flooding include...
  Glassboro, Clayton, Berlin, Buena, Chesilhurst, Newfield,
  Williamstown, Monroe Township and Sicklerville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

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 3976 7504 3983 7491 3979 7490 3978 7490
      3978 7488 3979 7484 3979 7482 3977 7479
      3975 7477 3973 7473 3951 7498 3967 7519
      3966 7522

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

$$

MPS
1 follow-up statement
797 
WGUS71 KPHI 020321
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
1121 PM EDT Tue Sep 1 2026

NJC001-007-015-020331-
/O.CAN.KPHI.FF.W.0152.000000T0000Z-260902T0530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Atlantic NJ-Camden NJ-Gloucester NJ-
1121 PM EDT Tue Sep 1 2026

...FLASH FLOOD WARNING IS CANCELLED FOR NORTHWESTERN ATLANTIC,
SOUTHEASTERN CAMDEN AND SOUTHEASTERN GLOUCESTER COUNTIES...

The heavy rain has ended. Flooding is no longer expected to pose a
threat. Please continue to heed remaining road closures.

&&

LAT...LON 3976 7504 3983 7491 3979 7490 3978 7490
      3978 7488 3979 7484 3979 7482 3977 7479
      3975 7477 3973 7473 3951 7498 3967 7519
      3966 7522

$$

MPS

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 1, 8:05 PM EDTSpecial Marine WarningPHI85 min
Sep 1, 8:08 PM EDTSevere Thunderstorm WarningPHIBurlington, Mercer, Middlesex, Monmouth, Ocean52 min
Sep 1, 8:11 PM EDTSpecial Marine WarningPHI94 min
Sep 1, 8:17 PM EDTSevere Thunderstorm WarningPHICumberland, Gloucester, Salem58 min
Sep 1, 8:26 PM EDTSevere Thunderstorm WarningPHIAtlantic, Camden, Cumberland, Gloucester49 min
Sep 1, 8:44 PM EDTFlash Flood WarningPHIGloucester, Salem3 hr
Sep 1, 8:46 PM EDTSevere Thunderstorm Warning Destructive damage threatPHICumberland, Salem59 min
Sep 1, 8:57 PM EDTSevere Thunderstorm WarningPHICamden, Gloucester, Salem48 min
Sep 1, 9:04 PM EDTSevere Thunderstorm WarningPHIBurlington, Ocean71 min
Sep 1, 9:07 PM EDTTornado WarningPHIBurlington21 min
Sep 1, 9:16 PM EDTTornado WarningPHIBurlington12 min
Sep 1, 9:19 PM EDTFlash Flood WarningPHIHunterdon, Mercer, Middlesex116 min
Sep 1, 9:22 PM EDTSpecial Marine WarningPHI68 min
Sep 1, 9:25 PM EDTSpecial Marine WarningPHI95 min
Sep 1, 9:33 PM EDTSevere Thunderstorm WarningPHIAtlantic, Burlington, Cape May, Ocean57 min
Sep 1, 9:54 PM EDTSevere Thunderstorm WarningPHIAtlantic, Cape May, Cumberland42 min
Sep 1, 10:06 PM EDTSpecial Marine WarningPHI84 min
Sep 1, 10:48 PM EDTSpecial Marine WarningPHI57 min
Sep 1, 11:12 PM EDTSpecial Marine WarningPHI63 min
Sep 2, 3:53 AM EDTHeat AdvisoryPHIBurlington, Camden, Gloucester, Mercer, Monmouth, Ocean40 hr

Nearby

Flash Flood Warnings in New Jersey, 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.