Alert archive / New Jersey / Flash Flood Warnings in 2026

Flash Flood Warning 91, NWS Philadelphia/Mount Holly

August 3, 2026Middlesex County, Somerset County, New Jersey

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 3, 2026, 5:59 AM EDT for Middlesex County, Somerset County, New Jersey. It was in force for 4 hr. 2 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
Aug 3, 2026, 5:59 AM EDT (09:59 UTC)
Expired
Aug 3, 2026, 10:00 AM EDT
In force
4 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

Counties Middlesex County, NJ, Somerset County, NJ

The radar

The Philadelphia radar (KDIX), 67 km from the middle of the area, began a volume at 09:58 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
Aug 3, 7:30 AM EDTRAIN 1.7Edison, NJRainfall total from midnight to 7:30 AM.
Aug 3, 7:30 AM EDTRAIN 2.67South River, NJRainfall total as of 7:30 AM.

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, 10.0 hours before the alert went out and 128 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 2026-08-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 151 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 2026-08-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 163 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
151 J/kg
Mixed-layer CIN
-2 J/kg
Mixed-layer LCL
507 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
163 m²/s²
0-3 km storm-relative helicity
198 m²/s²
Significant tornado parameter
0.1
Supercell composite
1.7

Open this sounding in Storm Lab

The text

As transmitted.

683 
WGUS51 KPHI 030959
FFWPHI
NJC023-035-031300-
/O.NEW.KPHI.FF.W.0091.260803T0959Z-260803T1300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
559 AM EDT Mon Aug 3 2026

The National Weather Service in Mount Holly has issued a

* Flash Flood Warning for...
  Middlesex County in northern New Jersey...
  Southeastern Somerset County in northern New Jersey...

* Until 900 AM EDT.

* At 559 AM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across portions of the warned area. Between 1 and 2 
  inches of rain have fallen. The expected rainfall rate is 1 to 2 
  inches in 1 hour. Additional rainfall amounts up 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...
  New Brunswick, Perth Amboy, Somerset, Edison, Old Bridge, East 
  Brunswick, Sayreville, North Brunswick, Carteret, Middlesex, Bound 
  Brook and Manville.

This includes the following highways...
	New Jersey Turnpike between exits 10 and 13.
	Interstate 287 in New Jersey between mile markers 0 and 13.
	Interstate 78 in New Jersey near mile marker 42.
	Garden State Parkway between mile markers 121 and 134.

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 4066 7443 4067 7440 4062 7443 4060 7446
      4061 7431 4059 7429 4060 7422 4059 7420
      4056 7422 4055 7425 4052 7425 4050 7426
      4049 7427 4046 7426 4045 7422 4038 7428
      4032 7436 4047 7468

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

$$

Deal
2 follow-up statements
388 
WGUS51 KPHI 031253
FFWPHI
NJC023-035-031400-
/O.EXT.KPHI.FF.W.0091.000000T0000Z-260803T1400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
853 AM EDT Mon Aug 3 2026

The National Weather Service in Mount Holly has extended the

* Flash Flood Warning for...
  Middlesex County in northern New Jersey...
  Southeastern Somerset County in northern New Jersey...

* Until 1000 AM EDT.

* At 853 AM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 3 inches of rain 
  have fallen. Additional rainfall amounts up to 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...
  New Brunswick, Perth Amboy, Somerset, Edison, Old Bridge, East 
  Brunswick, Sayreville, North Brunswick, Carteret, Middlesex, Bound 
  Brook and Manville.

This includes the following highways...
	New Jersey Turnpike between exits 10 and 13.
	Interstate 287 in New Jersey between mile markers 0 and 13.
	Garden State Parkway between mile markers 121 and 134.

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 4066 7443 4067 7440 4062 7443 4060 7446
      4061 7431 4059 7429 4060 7422 4059 7420
      4056 7422 4055 7425 4052 7425 4050 7426
      4049 7427 4046 7426 4045 7422 4038 7428
      4032 7436 4047 7468

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

$$

Deal
270 
WGUS71 KPHI 031356
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
956 AM EDT Mon Aug 3 2026

NJC023-035-031406-
/O.EXP.KPHI.FF.W.0091.000000T0000Z-260803T1400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Middlesex NJ-Somerset NJ-
956 AM EDT Mon Aug 3 2026

...FLASH FLOOD WARNING WILL EXPIRE AT 10 AM EDT THIS MORNING FOR 
MIDDLESEX AND SOUTHEASTERN SOMERSET COUNTIES...

The heavy rainfall is moving east of the warned area is not an is 
not expected to pose an immediate flash flood threat. Please 
continue to heed remaining road closures.

A Flood Watch remains in effect until 1100 PM EDT Monday for 
portions of northern Delaware, New Jersey, and Pennsylvania.

&&

LAT...LON 4066 7443 4067 7440 4062 7443 4060 7446
      4061 7431 4059 7429 4060 7422 4059 7420
      4056 7422 4055 7425 4052 7425 4050 7426
      4049 7427 4046 7426 4045 7422 4038 7428
      4032 7436 4047 7468

$$

Deal

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 2, 11:20 PM EDTFlash Flood WarningPHIWarren4 hr
Aug 3, 12:05 AM EDTFlash Flood WarningPHIHunterdon, Warren3 hr
Aug 3, 12:36 AM EDTSpecial Marine WarningPHI84 min
Aug 3, 2:50 AM EDTFlash Flood WarningPHIHunterdon, Mercer, Morris, Somerset4 hr
Aug 3, 3:05 AM EDTSevere Thunderstorm WarningPHIHunterdon, Mercer, Somerset40 min
Aug 3, 4:41 AM EDTFlash Flood WarningPHIBurlington, Camden, Gloucester, Mercer, Middlesex, Somerset2 hr
Aug 3, 7:02 AM EDTAreal Flood WarningPHIBurlington, Camden, Gloucester, Mercer, Middlesex, Somerset3 hr
Aug 3, 8:21 AM EDTSpecial Marine WarningPHI69 min
Aug 3, 9:08 AM EDTFlash Flood WarningPHIBurlington, Camden, Gloucester, Mercer, Salem3 hr
Aug 3, 10:12 AM EDTFlash Flood WarningPHIAtlantic, Cumberland, Salem86 min
Aug 3, 10:36 AM EDTFlash Flood WarningPHIBurlington, Mercer, Middlesex, Monmouth, Ocean, Somerset6 hr
Aug 3, 10:44 AM EDTFlash Flood Warning Considerable damage threatPHIBurlington, Camden, Gloucester6 hr
Aug 3, 12:01 PM EDTAreal Flood WarningPHIMercer74 min
Aug 3, 1:20 PM EDTAreal Flood WarningPHIBurlington, Camden, Mercer4 hr
Aug 3, 1:51 PM EDTSpecial Marine WarningPHI24 min
Aug 3, 2:53 PM EDTSpecial Marine WarningPHI97 min
Aug 3, 2:57 PM EDTSevere Thunderstorm WarningPHIBurlington, Ocean27 min
Aug 3, 5:15 PM EDTSpecial Marine WarningPHI90 min

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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.