Alert archive / New Jersey / Flash Flood Warnings in 2026

Flash Flood Warning 32, NWS Philadelphia/Mount Holly

July 9, 20264 counties in New Jersey

NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 9, 2026, 1:22 PM EDT for 4 counties in New Jersey. It was in force for 4 hr. 51 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, 2026, 1:22 PM EDT (17:22 UTC)
Expired
Jul 9, 2026, 5:30 PM EDT
In force
4 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

Counties Hunterdon County, NJ, Mercer County, NJ, Middlesex County, NJ, Somerset County, NJ

The radar

The Philadelphia radar (KDIX), 67 km from the middle of the area, began a volume at 17:23 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, 1:38 PM EDTFLASH FLOOD2 Se Highland Park, NJFlooding on New Jersey Turnpike Outer Roadway northbound and southbound North of Interchange 9 - NJ 18 (East Brunswick Twp) 1 Left lane of 3 lanes blocked. 1 Right lane of 3 lanes blocked.
Jul 9, 1:45 PM EDTRAIN 3.042 Ene Montgomery Twp, NJRainfall within the last 75 minutes.
Jul 9, 1:54 PM EDTFLASH FLOOD1 Ene Highland Park, NJFlooding on US 1 Southbound North of Woodbridge Av (Edison Twp), 2 right lanes of 3 lanes closed.
Jul 9, 2:00 PM EDTFLASH FLOOD1 Wsw South Brunswick, NJFlooding on US 1 Southbound South of New Rd (South Brunswick Twp), 1 right lane of 2 lanes closed.
Jul 9, 2:08 PM EDTRAIN 2.432 S Millstone, NJMesonet station FW1299 Blackwells Mills.
Jul 9, 2:10 PM EDTRAIN 2.832 Nne Dayton, NJMesonet station DEAN4 Deans.
Jul 9, 2:15 PM EDTRAIN 2.62 Sse Sergeantsville, NJMesonet station FW9889 Stockton.
Jul 9, 2:15 PM EDTRAIN 3.161 Nne Montgomery Twp, NJMesonet station BMDN4 0.6 E Belle Mead.
Jul 9, 2:16 PM EDTRAIN 2.191 E Middlebush, NJMesonet station GW2242 SOMERSET.
Jul 9, 2:16 PM EDTRAIN 2.541 Wsw Ringoes, NJMesonet station FW1999 Ringoes.
Jul 9, 2:17 PM EDTFLASH FLOOD1 Ssw Heathcote, NJFlooding on US 1 Both Directions South of Raymond Rd (South Brunswick Twp), 2 right lanes of 3 lanes, ramp lane closed southbound, 1 right lane of 3 lanes closed northbound.
Jul 9, 2:17 PM EDTRAIN 2.21Lambertville, NJMesonet station FW2229 Lambertville.
Jul 9, 2:20 PM EDTRAIN 2.021 Wsw Woodsville, NJMesonet station GW1239 Woodsville.
Jul 9, 2:20 PM EDTRAIN 2.42 Nw Skillman, NJMesonet station GW4041 HILLSBOROUGH.
Jul 9, 2:20 PM EDTRAIN 3.4Skillman, NJMesonet station EW0478 Skillman.
Jul 9, 2:20 PM EDTRAIN 4.832 Sw Kendall Park, NJMesonet station AV400 Kendall Park.
Jul 9, 2:30 PM EDTFLASH FLOODNew Brunswick, NJA county building had to be evacuated due to flooding. Time estimated.
Jul 9, 2:30 PM EDTRAIN 2.861 Sw Kendall Park, NJMesonet station KNDLL Kendall Park.
Jul 9, 2:36 PM EDTFLASH FLOOD1 N Dayton, NJFlooding on US 130 Both Directions South of CR 610/Deans Rhode Hall Rd (South Brunswick Twp), All lanes closed northbound, All lanes closed southbound.
Jul 9, 2:42 PM EDTFLASH FLOOD1 W Bound Brook, NJReport from mPING: Street/road flooding; Street/road closed; Vehicles stranded.
Jul 9, 2:52 PM EDTFLASH FLOOD1 Se Kendall Park, NJFlooding on US 1 Southbound North of Henderson Rd (South Brunswick Twp), All lanes closed.
Jul 9, 2:56 PM EDTFLASH FLOOD1 Wsw North Brunswick, NJFlooding on NJ 91 Both Directions North of Huron Rd (North Brunswick Twp), All lanes closed northbound, All lanes closed southbound.
Jul 9, 3:10 PM EDTRAIN 4.122 Nne Dayton, NJMesonet station DEAN4 Deans.
Jul 9, 3:13 PM EDTFLASH FLOOD1 Ene Hopewell, NJParts of Rte 518 between Montgomery and Hopewell closed due to flash flooding. Time given in report.
Jul 9, 3:15 PM EDTRAIN 3.241 Nne Montgomery Twp, NJMesonet station BMDN4 0.6 E Belle Mead.
Jul 9, 3:43 PM EDTRAIN 2.551 Wsw Ringoes, NJMesonet station FW1999 Ringoes.
Jul 9, 3:45 PM EDTRAIN 2.35Franklin Township, NJMesonet station MIDN4 Somerset.
Jul 9, 3:45 PM EDTRAIN 2.612 Sse Sergeantsville, NJMesonet station FW9889 Stockton.
Jul 9, 3:45 PM EDTRAIN 3.43Skillman, NJMesonet station EW0478 Skillman.
Jul 9, 3:46 PM EDTFLASH FLOOD1 Nnw North Brunswick, NJFlooding on NJ 27 Both Directions South of CR 617/Franklin Blvd (New Brunswick). All lanes closed northbound, All lanes closed southbound.
Jul 9, 3:46 PM EDTRAIN 2.412 Nw Skillman, NJMesonet station GW4041 HILLSBOROUGH.
Jul 9, 3:47 PM EDTRAIN 3.711 E Middlebush, NJMesonet station GW2242 SOMERSET.
Jul 9, 3:48 PM EDTRAIN 2.21Lambertville, NJMesonet station FW2229 Lambertville.
Jul 9, 3:48 PM EDTRAIN 3.362 S Millstone, NJMesonet station FW1299 Blackwells Mills.
Jul 9, 3:50 PM EDTRAIN 2.021 Wsw Woodsville, NJMesonet station GW1239 Woodsville.
Jul 9, 3:50 PM EDTRAIN 2.871 Sw Kendall Park, NJMesonet station KNDLL Kendall Park.
Jul 9, 3:50 PM EDTRAIN 4.912 Sw Kendall Park, NJMesonet station AV400 Kendall Park.
Jul 9, 4:45 PM EDTRAIN 2.37Franklin Township, NJMesonet station MIDN4 Somerset.
Jul 9, 5:10 PM EDTRAIN 4.122 Nne Dayton, NJMesonet station DEAN4 Deans.
Jul 9, 5:15 PM EDTRAIN 3.241 Nne Montgomery Twp, NJMesonet station BMDN4 0.6 E Belle Mead.
Jul 9, 5:33 PM EDTRAIN 2.21Lambertville, NJMesonet station FW2229 Lambertville.
Jul 9, 5:33 PM EDTRAIN 2.571 Wsw Ringoes, NJMesonet station FW1999 Ringoes.
Jul 9, 5:35 PM EDTRAIN 2.02Woodbridge, NJMesonet station EW5922 Woodbridge.
Jul 9, 5:35 PM EDTRAIN 2.622 Sse Sergeantsville, NJMesonet station FW9889 Stockton.
Jul 9, 5:37 PM EDTRAIN 2.422 Nw Skillman, NJMesonet station GW4041 HILLSBOROUGH.
Jul 9, 5:38 PM EDTRAIN 3.44Skillman, NJMesonet station EW0478 Skillman.
Jul 9, 5:38 PM EDTRAIN 3.711 E Middlebush, NJMesonet station GW2242 SOMERSET.
Jul 9, 5:39 PM EDTRAIN 3.362 S Millstone, NJMesonet station FW1299 Blackwells Mills.
Jul 9, 5:40 PM EDTRAIN 2.041 Wsw Woodsville, NJMesonet station GW1239 Woodsville.
Jul 9, 5:40 PM EDTRAIN 2.871 Sw Kendall Park, NJMesonet station KNDLL Kendall Park.
Jul 9, 5:40 PM EDTRAIN 4.912 Sw Kendall Park, NJMesonet station AV400 Kendall Park.

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 12:00Z, 5.4 hours before the alert went out and 153 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 12:00Z on 2026-07-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 20 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Brookhaven, NY at 12:00Z on 2026-07-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 53 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
20 J/kg
Mixed-layer CIN
-60 J/kg
Mixed-layer LCL
986 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
53 m²/s²
0-3 km storm-relative helicity
17 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

392 
WGUS51 KPHI 091722
FFWPHI
NJC019-021-023-035-092130-
/O.NEW.KPHI.FF.W.0032.260709T1722Z-260709T2130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
122 PM EDT Thu Jul 9 2026

The National Weather Service in Mount Holly has issued a

* Flash Flood Warning for...
  Northern Mercer County in central New Jersey...
  Middlesex County in northern New Jersey...
  Somerset County in northern New Jersey...
  Southeastern Hunterdon County in northwestern New Jersey...

* Until 530 PM EDT.

* At 122 PM EDT, Doppler radar and automated rain gauges indicated 
  thunderstorms producing heavy rain across the warned area. Between 
  1 and 2 inches of rain have fallen. The expected rainfall rate is 
  2 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 and automated gauges.

  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, Somerville, Somerset, Edison, East 
  Brunswick, Bridgewater, South Brunswick, Sayreville, North 
  Brunswick, Ewing and Carteret.

This includes the following highways...
	Interstate 295 in New Jersey between mile markers 67 and 76.
	New Jersey Turnpike between exits 10 and 13.
	Interstate 287 in New Jersey between mile markers 0 and 20.
	Interstate 78 in New Jersey between mile markers 33 and 42.
	Garden State Parkway between mile markers 125 and 134.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4042 7506 4045 7507 4068 7453 4065 7452
      4067 7446 4066 7445 4066 7440 4065 7441
      4063 7442 4062 7443 4060 7446 4059 7420
      4048 7427 4027 7467 4026 7485 4034 7494
      4040 7497

FLASH FLOOD...RADAR AND GAUGE INDICATED
EXPECTED RAINFALL RATE...2-3 INCHES IN 1 HOUR

$$

Cooper
2 follow-up statements
292 
WGUS71 KPHI 091819
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
219 PM EDT Thu Jul 9 2026

NJC019-021-023-035-092130-
/O.CON.KPHI.FF.W.0032.000000T0000Z-260709T2130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hunterdon NJ-Mercer NJ-Middlesex NJ-Somerset NJ-
219 PM EDT Thu Jul 9 2026

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 530 PM EDT THIS 
AFTERNOON FOR NORTHERN MERCER, MIDDLESEX, SOMERSET AND SOUTHEASTERN 
HUNTERDON COUNTIES...

At 219 PM EDT, local law enforcement reported thunderstorms 
producing heavy rain across the warned area. Flooding has been 
reported along portions of Route 1 and the New Jersey Turnpike. 
Between 1 and 3 inches of rain have fallen. The expected rainfall 
rate is 2 to 3 inches in 1 hour. Additional rainfall amounts of 1 to 
2 inches are possible in the warned area. Flash flooding is already 
occurring.

HAZARD...Life threatening flash flooding caused by thunderstorms.

SOURCE...Law enforcement reported.

IMPACT...Life threatening flash flooding of creeks and streams,
         urban areas, highways, streets, and underpasses.

Some locations that may experience flash flooding include...
  New Brunswick, Perth Amboy, Somerville, Somerset, Edison, East 
  Brunswick, Bridgewater, South Brunswick, Sayreville, North 
  Brunswick, Carteret and Middlesex.

This includes the following highways...
	Interstate 295 in New Jersey between mile markers 67 and 70.
	New Jersey Turnpike between exits 10 and 12.
	Interstate 287 in New Jersey between mile markers 0 and 20.
	Interstate 78 in New Jersey between mile markers 33 and 42.
	Garden State Parkway between mile markers 125 and 133.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4068 7453 4065 7452 4067 7446 4066 7445
      4066 7440 4063 7442 4060 7446 4059 7421
      4056 7422 4055 7425 4052 7425 4050 7426
      4050 7428 4048 7427 4027 7467 4030 7481
      4047 7503

FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
EXPECTED RAINFALL RATE...2-3 INCHES IN 1 HOUR

$$

Cooper
875 
WGUS71 KPHI 092125
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
525 PM EDT Thu Jul 9 2026

NJC019-021-023-035-092135-
/O.EXP.KPHI.FF.W.0032.000000T0000Z-260709T2130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hunterdon NJ-Mercer NJ-Middlesex NJ-Somerset NJ-
525 PM EDT Thu Jul 9 2026

...FLASH FLOOD WARNING WILL EXPIRE AT 530 PM EDT THIS AFTERNOON FOR 
NORTHERN MERCER, MIDDLESEX, SOMERSET AND SOUTHEASTERN HUNTERDON 
COUNTIES...

The heavy rain has ended. Please continue to heed remaining road 
closures.

&&

LAT...LON 4068 7453 4065 7452 4067 7446 4066 7445
      4066 7440 4063 7442 4060 7446 4059 7421
      4056 7422 4055 7425 4052 7425 4050 7426
      4050 7428 4048 7427 4027 7467 4030 7481
      4047 7503

$$

Cooper

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 9, 2:09 AM EDTFlood WatchPHIAtlantic, Burlington, Camden, Cumberland, Gloucester, Hunterdon and 6 more19 hr
Jul 9, 1:37 PM EDTFlash Flood WarningPHIGloucester, Salem6 hr
Jul 9, 2:00 PM EDTFlash Flood Warning Considerable damage threatPHICamden, Gloucester5 hr
Jul 9, 2:42 PM EDTFlash Flood WarningPHIMiddlesex, Monmouth4 hr
Jul 9, 3:01 PM EDTFlash Flood WarningPHIBurlington4 hr
Jul 9, 4:32 PM EDTFlash Flood WarningPHIBurlington, Camden, Gloucester4 hr
Jul 9, 5:30 PM EDTSevere Thunderstorm WarningPHIGloucester, Salem45 min
Jul 9, 5:34 PM EDTSpecial Marine WarningPHI26 min
Jul 9, 7:31 PM EDTFlash Flood WarningPHIAtlantic, Cape May, Cumberland119 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.