Alert archive / New Jersey / Flash Flood Warnings in 2023

Flash Flood Warning 54, NWS Philadelphia/Mount Holly

July 15, 20234 counties in New Jersey; Bucks County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 15, 2023, 5:18 PM EDT for 4 counties in New Jersey; Bucks County, Pennsylvania. It was in force for 4 hr. 33 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 15, 2023, 5:18 PM EDT (21:18 UTC)
Expired
Jul 15, 2023, 9:30 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, Bucks County, PA

The radar

The Philadelphia radar (KDIX), 54 km from the middle of the area, began a volume at 21:18 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 15, 5:18 PM EDTFLOODYardley, PAReport of Street Flooding along Route 32 (River Road) in Yardley.
Jul 15, 5:24 PM EDTFLOOD1 Nw Rocky Hill, NJVideo of street flooding at the intersection of Sycamore Lane and Route 206.
Jul 15, 5:30 PM EDTFLOOD1 Sw Washington Crossin, PASignificant flooding occurred earlier at the intersection of Wrightstown Rd and Washington Crossing Road. Time estimated.
Jul 15, 5:32 PM EDTFLASH FLOOD2 Sw Washington Crossin, PATrained Spotter relays report of a water rescue at the intersection of Washington Crossing Road and Dolington Acres Rd in Washington Crossing. Time estimated.
Jul 15, 5:35 PM EDTFLOOD1 Ene Highland Park, NJNJ DOT - STMC: Flooding on US 1 southbound Plainfield Av (Edison Twp) All lanes closed.
Jul 15, 5:35 PM EDTFLASH FLOOD1 Ene Highland Park, NJMuch of Route 1 South in Edison is flooded. All lanes are closed. With a report of several stalled cars.
Jul 15, 5:36 PM EDTFLOOD2 Wsw Trenton Mercer Ai, NJNJ DOT - STMC: Flooding on NJ 29 both directions Bernard Dr (Ewing Twp) All lanes closed. Time estimated.
Jul 15, 5:37 PM EDTFLOOD1 W North Brunswick, NJPhoto of street flooding on Omaha Road between Aex Ave and Redmond St in North Brunswick.
Jul 15, 5:41 PM EDTFLOOD1 Sw Sayreville, NJReport of street flooding at the intersection of Jernee Mill Rd and Washington Rd in Sayreville. Time estimated.
Jul 15, 5:56 PM EDTFLOOD1 Sw North Brunswick, NJNJ DOT - STMC: Flooding on US 1 northbound ramp to Adams Ln/Cozzens Ln (North Brunswick Twp) All lanes closed.
Jul 15, 6:00 PM EDTFLOOD1 Nnw Hopelawn, NJSocial media report and pictures showing roadway flooding on US Route 9 near Woodbridge. Water appears to be about 1 to 2 feet deep. Estimated time.
Jul 15, 6:00 PM EDTFLOOD1 Wnw South River, NJNJ DOT - STMC: Flooding on NJ 18 northbound South of West Prospect St (East Brunswick Twp) All lanes closed.
Jul 15, 6:19 PM EDTFLOOD1 Nw North Brunswick, NJNJ DOT - STMC: Flooding on NJ 27 both directions South of CR 617/Franklin Blvd (New Brunswick) All lanes closed.
Jul 15, 6:30 PM EDTFLOOD2 Wsw Trenton Mercer Ai, NJNJ Route 29 near Duffield Drive closed due to flooding.
Jul 15, 6:55 PM EDTFLOOD1 Sw North Brunswick, NJPhoto of Route 91 (Jersey Ave) flooded with 2 cars stuck in flood waters between Huron Rd and Corporate Rd in North Brunswick.
Jul 15, 6:55 PM EDTFLOOD1 Sw North Brunswick, NJRoute 91/Jersey Ave. flooded with about a foot between Huron Road and Corporate Road in North Brunswick NJ. Social media picture shows a vehicle stuck in the water with a water assist ongoing.
Jul 15, 7:02 PM EDTFLASH FLOOD1 Nw Yardley, PATrained Spotter reports impassable roads with water rescues occurring on Taylorsville Road, just off of the I-295 exit.
Jul 15, 7:05 PM EDTFLOODPennington, NJNJ Route 31 at Delaware Avenue in Pennington is impassible due to flood waters. Report relayed via NWS Employee. Photo shows about 1 to 2 feet of standing water in the intersection.
Jul 15, 7:15 PM EDTRAIN 2.53South River, NJStorm total.
Jul 15, 7:30 PM EDTRAIN 3.65Washington Crossing, NJStorm total.
Jul 15, 7:39 PM EDTRAIN 4.662 Ese Washington Crossi, NJStorm total.
Jul 15, 8:53 PM EDTRAIN 2.69Trenton Mercer Airport, NJASOS station KTTN Trenton.
Jul 15, 9:00 PM EDTRAIN 4.64Washington Crossing, PAMesonet station WASN4 Washington Crossing.
Jul 15, 9:15 PM EDTRAIN 2.881 Nne Blawenburg, NJMesonet station SKIN4 0.8 NE Blawenburg.
Jul 15, 9:30 PM EDTRAIN 3.612 W Princeton, NJMesonet station FW0303 Princeton.
Jul 15, 9:30 PM EDTRAIN 3.771 Ene Sayreville, NJMesonet station DW5872 Sayreville.
Jul 15, 9:36 PM EDTRAIN 4.05Lambertville, NJMesonet station FW2229 Lambertville.
Jul 15, 9:38 PM EDTRAIN 2.521 Ene Skillman, NJMesonet station EW0478 Skillman.
Jul 15, 9:39 PM EDTRAIN 4.42 Ese Washington Crossi, NJMesonet station GW1897 EWING.
Jul 15, 9:40 PM EDTRAIN 2.042 Nw West Amwell, NJMesonet station LMBWM 1 NE Lambertville.
Jul 15, 9:40 PM EDTRAIN 2.291 Wsw Woodsville, NJMesonet station GW1239 Woodsville.
Jul 15, 9:40 PM EDTRAIN 2.82 Sw Kendall Park, NJMesonet station AV400 Kendall Park.
Jul 15, 9:40 PM EDTRAIN 2.912 W North Princeton, NJMesonet station PRSCD Princeton (Stuart).

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, 9.3 hours before the alert went out and 155 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 2023-07-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1125 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 12:00Z on 2023-07-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 47 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
1125 J/kg
Mixed-layer CIN
-3 J/kg
Mixed-layer LCL
596 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
47 m²/s²
0-3 km storm-relative helicity
100 m²/s²
Significant tornado parameter
0.2
Supercell composite
2.4

Open this sounding in Storm Lab

The text

As transmitted.

668 
WGUS51 KPHI 152118
FFWPHI
NJC019-021-023-035-PAC017-160130-
/O.NEW.KPHI.FF.W.0054.230715T2118Z-230716T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
518 PM EDT Sat Jul 15 2023

The National Weather Service in Mount Holly has issued a

* Flash Flood Warning for...
  Northwestern Mercer County in central New Jersey...
  Central Middlesex County in northern New Jersey...
  Southern Somerset County in northern New Jersey...
  Southeastern Hunterdon County in northwestern New Jersey...
  East Central Bucks County in southeastern Pennsylvania...

* Until 930 PM EDT.

* At 518 PM EDT, Doppler radar and automated rain gauges indicated 
  thunderstorms producing heavy rain across the warned area. Between 
  2 and 3 inches of rain have fallen. 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...
  Trenton, New Brunswick, Somerset, Edison, East Brunswick, South 
  Brunswick, Sayreville, North Brunswick, Ewing, Princeton, 
  Pennington, and New Hope.

This includes the following highways...
	New Jersey Turnpike between exits 10 and 12.
	Interstate 295 in New Jersey between mile markers 70 and 76.
	Interstate 287 in New Jersey between mile markers 0 and 4.
	Garden State Parkway between mile markers 124 and 132.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4041 7493 4049 7471 4058 7430 4050 7428
      4049 7429 4049 7428 4048 7427 4047 7427
      4030 7469 4021 7487 4022 7500 4032 7499

FLASH FLOOD...RADAR AND GAUGE INDICATED

$$

PO
2 follow-up statements
886 
WGUS71 KPHI 152301
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
701 PM EDT Sat Jul 15 2023

NJC019-021-023-035-PAC017-160130-
/O.CON.KPHI.FF.W.0054.000000T0000Z-230716T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hunterdon NJ-Mercer NJ-Middlesex NJ-Somerset NJ-Bucks PA-
701 PM EDT Sat Jul 15 2023

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 930 PM EDT THIS 
EVENING FOR NORTHWESTERN MERCER, CENTRAL MIDDLESEX, SOUTHERN 
SOMERSET, SOUTHEASTERN HUNTERDON, AND EAST CENTRAL BUCKS COUNTIES...

At 701 PM EDT, local law enforcement reported thunderstorms 
producing heavy rain in central Middlesex County. Between 2 and 4.5 
inches of rain have fallen. Flash flooding is already occurring.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Law enforcement 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...
  New Brunswick, Somerset, Edison, East Brunswick, South Brunswick, 
  Sayreville, North Brunswick, Princeton, Pennington, New Hope, 
  Hopewell, and Rocky Hill.

This includes the following highways...
	New Jersey Turnpike between exits 10 and 12.
	Interstate 287 in New Jersey between mile markers 0 and 4.
	Garden State Parkway between mile markers 124 and 132.

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 4041 7493 4049 7471 4058 7430 4050 7428
      4049 7429 4049 7428 4047 7427 4030 7469
      4035 7484 4025 7495 4021 7493 4022 7500
      4032 7499

FLASH FLOOD...OBSERVED

$$

Staarmann
641 
WGUS71 KPHI 160122
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
922 PM EDT Sat Jul 15 2023

NJC019-021-023-035-PAC017-160132-
/O.EXP.KPHI.FF.W.0054.000000T0000Z-230716T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hunterdon NJ-Mercer NJ-Middlesex NJ-Somerset NJ-Bucks PA-
922 PM EDT Sat Jul 15 2023

...FLASH FLOOD WARNING WILL EXPIRE AT 930 PM EDT THIS EVENING FOR 
NORTHWESTERN MERCER, CENTRAL MIDDLESEX, SOUTHERN SOMERSET, 
SOUTHEASTERN HUNTERDON, AND EAST CENTRAL BUCKS COUNTIES...

The heavy rain has ended, and flood waters are receding. Flooding is 
no longer expected to pose a threat.

Additional heavy rain is forecast in the area overnight and Sunday. 
Remain alert for additional warnings and potential for additional 
flooding.

A Flood Watch remains in effect until midnight Sunday night.

LAT...LON 4041 7493 4049 7471 4058 7430 4050 7428
      4049 7429 4049 7428 4047 7427 4030 7469
      4035 7484 4025 7495 4021 7493 4022 7500
      4032 7499

$$

Staarmann

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 14, 8:05 PM EDTSpecial Weather StatementPHIMorris40 min
Jul 14, 8:29 PM EDTFlash Flood WarningPHIMorris4 hr
Jul 14, 9:13 PM EDTAreal Flood AdvisoryPHIHunterdon, Morris, Somerset, Warren3 hr
Jul 14, 9:51 PM EDTSpecial Weather StatementPHIMorris, Somerset24 min
Jul 14, 9:57 PM EDTSevere Thunderstorm WarningPHIMiddlesex, Morris, Somerset41 min
Jul 14, 11:32 PM EDTSpecial Weather StatementPHIMercer, Monmouth28 min
Jul 15, 3:44 AM EDTFlood WatchPHIAtlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and 10 more38 hr
Jul 15, 1:33 PM EDTSpecial Marine WarningPHI57 min
Jul 15, 1:43 PM EDTSpecial Weather StatementPHISalem32 min
Jul 15, 2:56 PM EDTSpecial Weather StatementPHIMercer34 min
Jul 15, 3:08 PM EDTSpecial Weather StatementPHIHunterdon37 min
Jul 15, 3:22 PM EDTSevere Thunderstorm WarningPHIMiddlesex, Somerset38 min
Jul 15, 3:29 PM EDTSpecial Marine WarningPHI61 min
Jul 15, 3:30 PM EDTSpecial Weather StatementPHISalem30 min
Jul 15, 3:40 PM EDTSevere Thunderstorm WarningPHICumberland, Salem65 min
Jul 15, 4:08 PM EDTSevere Thunderstorm WarningPHIHunterdon, Mercer, Somerset67 min
Jul 15, 4:11 PM EDTSpecial Weather StatementPHIGloucester34 min
Jul 15, 4:31 PM EDTAreal Flood AdvisoryPHIHunterdon, Mercer106 min
Jul 15, 4:52 PM EDTSpecial Weather StatementPHICumberland23 min
Jul 15, 4:53 PM EDTSpecial Weather StatementPHIMiddlesex37 min
Jul 15, 5:00 PM EDTAreal Flood AdvisoryPHIHunterdon, Mercer, Middlesex, Somerset2 hr
Jul 15, 5:12 PM EDTSevere Thunderstorm WarningPHIMercer, Middlesex63 min
Jul 15, 5:27 PM EDTAreal Flood AdvisoryPHICumberland, Salem99 min
Jul 15, 5:45 PM EDTSevere Thunderstorm WarningPHIHunterdon, Morris, Sussex, Warren45 min
Jul 15, 5:49 PM EDTSevere Thunderstorm WarningPHIMiddlesex, Monmouth41 min
Jul 15, 6:09 PM EDTFlash Flood Warning Considerable damage threatPHIMercer4 hr
Jul 15, 6:21 PM EDTSpecial Weather StatementPHIMercer24 min
Jul 14, 8:50 PM EDTAreal Flood AdvisoryPHICarbon, Lehigh, Monroe, Northampton3 hr
Jul 15, 1:46 PM EDTSpecial Weather StatementPHIMontgomery29 min
Jul 15, 3:35 PM EDTSpecial Weather StatementPHIBerks25 min
Jul 15, 3:51 PM EDTSpecial Weather StatementPHIBucks24 min
Jul 15, 7:46 PM EDTSpecial Weather StatementPHICarbon29 min
Jul 15, 7:53 PM EDTSevere Thunderstorm WarningPHICarbon52 min

Nearby

Flash Flood Warnings in New Jersey, 2023Flash Flood Warnings in Pennsylvania, 2023Every flash flood warning in 2023

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.