Alert archive / New Jersey / Flash Flood Warnings in 2021

Flash Flood Warning 48, NWS Philadelphia/Mount Holly

August 22, 2021Middlesex County, Monmouth County, New Jersey

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 22, 2021, 2:04 AM EDT for Middlesex County, Monmouth County, New Jersey. It was in force for 9 hr. 39 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 22, 2021, 2:04 AM EDT (06:04 UTC)
Expired: Aug 22, 2021, 10:49 AM EDT
In force: 9 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

Counties Middlesex County, NJ, Monmouth County, NJ

The radar

The Philadelphia radar (KDIX), 52 km from the middle of the area, began a volume at 06:07 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

Time	Report	Where	Remark
Aug 22, 2:45 AM EDT	FLOOD	Freehold, NJ	REPORTS OF ROAD FLOODING IN FREEHOLD BORO. TIME ESTIMATED FROM RADAR.
Aug 22, 3:30 AM EDT	FLASH FLOOD	1 Sw South River, NJ	NJ 18 CLOSED AT CRANBURY ROAD DUE TO FLOODING. TIME ESTIMATED.
Aug 22, 3:45 AM EDT	FLASH FLOOD	1 Ene Highland Park, NJ	US 1 CLOSED IN EDISON TOWNSHIP DUE TO FLOODING. TIME ESTIMATED.
Aug 22, 4:45 AM EDT	FLASH FLOOD	1 Nnw North Brunswick, NJ	NJ 91 CLOSED BETWEEN NEW BRUNSWICK AND NORTH BRUNSWICK DUE TO FLOODING. TIME ESTIMATED.
Aug 22, 5:00 AM EDT	FLASH FLOOD	1 N Spotswood, NJ	OLD STAGE ROAD CLOSED AT SUMMERHILL ROAD. TIME BASED ON NEARBY REPORTS.
Aug 22, 5:15 AM EDT	FLASH FLOOD	Jamesburg, NJ	RAILROAD AVENUE WAS UNDER WATER IN JAMESBURG NEAR FORSGATE DRIVE. A WATER RESCUE WAS IN PROGRESS.
Aug 22, 5:30 AM EDT	FLASH FLOOD	3 Ne Perrineville, NJ	SEVERAL ROADS CLOSED IN THE MANALAPAN AREA. TIME BASED ON RADAR AND NEARBY REPORTS.
Aug 22, 5:39 AM EDT	FLASH FLOOD	1 Se Dayton, NJ	U.S. HIGHWAY 130 CLOSED FROM FLOODING BETWEEN GEORGES ROAD AND DEANS RHODE HALL ROAD. TIME BASED ON DISPATCH REPORT.
Aug 22, 5:45 AM EDT	FLASH FLOOD	Jamesburg, NJ	SEVERE FLASH FLOODING OCCURRING. NUMEROUS ROADS CLOSED AND RESIDENCE FLOODING ONGOING.
Aug 22, 5:53 AM EDT	FLOOD	1 Ne Parlin, NJ	FLOODING ON GARDEN STATE PARKWAY SOUTHBOUND NORTH OF EXIT 123. LANE RESTRICTIONS REQUIRED. TIME BASED ON DISPATCH REPORT.
Aug 22, 5:59 AM EDT	FLASH FLOOD	1 Ese Yorketown, NJ	TENNENT ROAD CLOSED BETWEEN TAYLORS MILL ROAD AND SANDYBROOK ROAD FROM FLOODING. TIME BASED ON DISPATCH REPORT.
Aug 22, 6:00 AM EDT	FLASH FLOOD	Helmetta, NJ	SEVERAL WATER RESCUES VIA BOAT IN HELMETTA. RESIDENCES EVACUATED FROM FLOODING. TIME BASED ON NEARBY DISPATCH REPORTS AND SOCIAL MEDIA POSTS.
Aug 22, 6:00 AM EDT	FLASH FLOOD	Milltown, NJ	SUBSTANTIAL FLOODING IN MILLTOWN WITH NUMEROUS ROADS CLOSED AND VEHICLES SUBMERGED IN WATER. A BUSINESS AND SEVERAL RESIDENCES WERE FLOODED. TIME ESTIMATED.
Aug 22, 6:06 AM EDT	HEAVY RAIN 6.5	Cranbury, NJ	AS OF 6 AM. SPOTTER REPORTED BASEMENT FLOODING.
Aug 22, 6:10 AM EDT	FLASH FLOOD	1 E Plainsboro Township, NJ	VEHICLE STUCK IN WATER AND WATER RESCUE ON WOODLAND DRIVE. TIME BASED ON DISPATCH REPORT.
Aug 22, 6:10 AM EDT	FLASH FLOOD	1 Sw Cranbury, NJ	SEVERAL WATER RESCUES IN PROGRESS IN CRANBURY. TIME BASED ON DISPATCH REPORTS.
Aug 22, 6:15 AM EDT	FLASH FLOOD	1 Sse Highland Park, NJ	THE GAUGE ON LAWRENCE BROOK AT WESTON MILLS (LABN4) REACHED MINOR FLOOD STAGE.
Aug 22, 6:15 AM EDT	FLASH FLOOD	Monmmouth Junction, NJ	WATER RESCUES IN PROGRESS ON RIDGE ROAD. TIME BASED ON DISPATCH REPORTS.
Aug 22, 6:30 AM EDT	FLASH FLOOD	South River, NJ	MULTIPLE ROADS CLOSED AND VEHICLES STUCK IN WATER IN THE SOUTH RIVER AREA. TIME BASED ON DISPATCH REPORTS.
Aug 22, 6:47 AM EDT	HEAVY RAIN 8.28	Cranbury, NJ	AS OF 6:45 AM. SPOTTER REPORTED BASEMENT FLOODING.
Aug 22, 6:49 AM EDT	FLASH FLOOD	1 S Heathcote, NJ	FLOODING ON U.S. HIGHWAY 1 NEAR RAYMOND ROAD. CLOSURES IN PLACE.
Aug 22, 6:55 AM EDT	FLASH FLOOD	2 E Plainsboro Township, NJ	WATER RESCUE ON DEY ROAD. TIME BASED ON DISPATCH REPORT.
Aug 22, 7:00 AM EDT	HEAVY RAIN 4.01	2 Ene Kendall Park, NJ	COCORAHS STATION NJ-MD-2 NORTH BRUNSWICK TWP 1.5 W.
Aug 22, 7:00 AM EDT	HEAVY RAIN 7.5	Plainsboro Township, NJ
Aug 22, 7:15 AM EDT	FLASH FLOOD	Jamesburg, NJ	WATER INUNDATING RAILROAD AVENUE AND FORSGATE DRIVE WITH WATER IN RESIDENCES AND VEHICLES STRANDED.
Aug 22, 7:15 AM EDT	FLASH FLOOD	Jamesburg, NJ	RESIDENCES FLOODED AND OCCUPANTS EVACUATED NEAR MANALAPAN BROOK.
Aug 22, 7:30 AM EDT	FLASH FLOOD	1 S Jamesburg, NJ	WIDESPREAD FLOODING IN MONROE TOWNSHIP. SEVERAL ROADS ARE CLOSED AND VEHICLES ARE STRANDED IN WATER.
Aug 22, 7:30 AM EDT	FLASH FLOOD	Cranbury, NJ	WATER RESCUE ON SOUTH RIVER ROAD AND PROSPECT PLAINS ROAD. TIME BASED ON DISPATCH REPORT.
Aug 22, 7:45 AM EDT	FLASH FLOOD	1 Sw Helmetta, NJ	MAIN STREET CLOSED NEAR HELMETTA AVENUE FROM FLOODING.
Aug 22, 8:00 AM EDT	FLASH FLOOD	2 Ene Cranbury, NJ	OVER 150 RESIDENTS WERE RESCUED OR EVACUATED BY BOAT IN MIDDLESEX COUNTY, NOTABLY IN THE JAMESBURG AND ROSSMOOR AREAS. TIME BASED ON DISPATCH REPORT AND SOCIAL MEDIA POSTS.
Aug 22, 8:00 AM EDT	HEAVY RAIN 1.98	1 Nw Highland Park, NJ	COCORAHS STATION NJ-MD-86 HIGHLAND PARK 0.4 N.
Aug 22, 8:00 AM EDT	HEAVY RAIN 3.1	1 E Eatontown, NJ	COCORAHS STATION NJ-MN-10 EATONTOWN 1.2 NE.
Aug 22, 8:21 AM EDT	FLASH FLOOD	2 E Twin Rivers, NJ	FLOODING ON STATE HIGHWAY 33 EAST OF APPLEGARTH ROAD. ALL LANES CLOSED. TIME BASED ON DISPATCH REPORT.
Aug 22, 8:30 AM EDT	FLASH FLOOD	2 Se Dayton, NJ	HERROD BOULEVARD CLOSED FROM FLOODING WITH SEVERAL WATER RESCUES AND STRANDED VEHICLES.
Aug 22, 8:40 AM EDT	FLOOD	1 W Laurence Harbor, NJ	FLOODING ON GARDEN STATE PARKWAY IN THE CHEESEQUAKE SERVICE AREA TO EXIT 105.
Aug 22, 9:08 AM EDT	HEAVY RAIN 8.91	Cranbury, NJ
Aug 22, 9:08 AM EDT	HEAVY RAIN 9.44	Cranbury, NJ	36 HOUR TOTAL.
Aug 22, 9:11 AM EDT	FLOOD	Cranbury, NJ	BRAINERD LAKE IS OVERFLOWING ITS BANKS, MAIN STREET IS CLOSED. 3 FEET OF WATER IN NEARBY RESIDENTS.
Aug 22, 10:27 AM EDT	FLOOD	1 Wnw Yorketown, NJ	CONMACK LANE, WILSON AVENUE, AND SOBECHO ROAD CLOSED FROM FLOODING. TIME BASED ON DISPATCH REPORTS AND SOCIAL MEDIA POSTS.

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, 6.1 hours before the alert went out and 134 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1163 J/kg
Mixed-layer CIN: -6 J/kg
Mixed-layer LCL: 543 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: 75 m²/s²
0-3 km storm-relative helicity: 85 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 1.7

Open this sounding in Storm Lab

The text

As transmitted.

865 
WGUS51 KPHI 220604
FFWPHI
NJC023-025-221100-
/O.NEW.KPHI.FF.W.0048.210822T0604Z-210822T1100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
204 AM EDT Sun Aug 22 2021

The National Weather Service in Mount Holly has issued a

* Flash Flood Warning for...
  Northern Monmouth County in central New Jersey...
  Middlesex County in northern New Jersey...

* Until 700 AM EDT.

* At 204 AM EDT, Doppler radar indicated heavy rain across the 
  warned area. Between 0.5 and 1.5 inches of rain have already 
  fallen in spots. Additional rainfall amounts of 2 to 3 inches are 
  possible in the warned area. Flash flooding is ongoing or expected 
  to begin shortly.

  HAZARD...Flash flooding caused by heavy rain.

  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 will experience flash flooding include...
  New Brunswick, Perth Amboy, Somerset, Edison, Middletown, Old 
  Bridge, East Brunswick, South Brunswick, Sayreville, North 
  Brunswick, Marlboro, and Manalapan.

This includes the following highways...
	New Jersey Turnpike between exits 9 and 13.
	Interstate 287 in New Jersey between mile markers 0 and 10.
	Garden State Parkway between mile markers 102 and 134.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Motorists should not attempt to drive around barricades or drive 
cars through flooded areas.

&&

LAT...LON 4027 7448 4034 7463 4042 7459 4049 7446
      4056 7453 4058 7451 4060 7422 4056 7422
      4050 7428 4047 7427 4044 7421 4046 7414
      4041 7402 4033 7401 4022 7408 4024 7449
      4024 7448

FLASH FLOOD...RADAR INDICATED

$$

Iovino

3 follow-up statements

967 
WGUS51 KPHI 221050
FFWPHI
NJC023-025-221500-
/O.EXT.KPHI.FF.W.0048.000000T0000Z-210822T1500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
650 AM EDT Sun Aug 22 2021

The National Weather Service in Mount Holly has extended the

* Flash Flood Warning for...
  Northern Monmouth County in central New Jersey...
  Middlesex County in northern New Jersey...

* Until 1100 AM EDT.

* At 650 AM EDT, Doppler radar indicated heavy rain across the 
  warned area. Between 3 and 8 inches of rain have fallen. 
  Additional rainfall amounts of 0.5 to 1 inch are possible in the 
  warned area. Flash flooding is ongoing or expected to begin 
  shortly.

  HAZARD...Flash flooding caused by heavy rain.

  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 will experience flash flooding include...
  New Brunswick, Perth Amboy, Somerset, Edison, Middletown, Old 
  Bridge, East Brunswick, South Brunswick, Sayreville, North 
  Brunswick, Marlboro, and Manalapan.

This includes the following highways...
	New Jersey Turnpike between exits 9 and 13.
	Interstate 287 in New Jersey between mile markers 0 and 10.
	Garden State Parkway between mile markers 102 and 133.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Motorists should not attempt to drive around barricades or drive 
cars through flooded areas.

&&

LAT...LON 4027 7448 4034 7463 4042 7459 4049 7446
      4056 7453 4058 7451 4060 7422 4056 7422
      4050 7428 4047 7427 4044 7421 4046 7414
      4041 7402 4033 7401 4022 7408 4024 7449
      4024 7448

FLASH FLOOD...RADAR INDICATED

$$

Iovino

957 
WGUS71 KPHI 221138
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
738 AM EDT Sun Aug 22 2021

NJC023-025-221500-
/O.CON.KPHI.FF.W.0048.000000T0000Z-210822T1500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Middlesex NJ-Monmouth NJ-
738 AM EDT Sun Aug 22 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 11 AM EDT THIS 
MORNING FOR NORTHERN MONMOUTH AND MIDDLESEX COUNTIES...

At 738 AM EDT, local law enforcement reported flash flooding in the 
warned area. Numerous water rescues have been reported in the South 
Brunswick, Cranbury, South River, and Jamesburg areas. Numerous 
roads are closed. Travel is strongly discouraged. Between 3 and 8 
inches of rain have fallen. 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 heavy rain.

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 will experience flash flooding include...
  New Brunswick, Perth Amboy, Somerset, Edison, Middletown, Old 
  Bridge, East Brunswick, South Brunswick, Sayreville, North 
  Brunswick, Marlboro, and Manalapan.

This includes the following highways...
	New Jersey Turnpike between exits 9 and 13.
	Interstate 287 in New Jersey between mile markers 0 and 10.
	Garden State Parkway between mile markers 102 and 133.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4027 7448 4034 7463 4042 7459 4049 7446
      4056 7453 4058 7451 4060 7422 4056 7422
      4050 7428 4047 7427 4044 7421 4046 7414
      4041 7402 4033 7401 4022 7408 4024 7449
      4024 7448

FLASH FLOOD...OBSERVED

$$

CMS

991 
WGUS71 KPHI 221449
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
1049 AM EDT Sun Aug 22 2021

NJC023-025-221459-
/O.CAN.KPHI.FF.W.0048.000000T0000Z-210822T1500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Middlesex NJ-Monmouth NJ-
1049 AM EDT Sun Aug 22 2021

...FLASH FLOOD WARNING FOR NORTHERN MONMOUTH AND MIDDLESEX COUNTIES 
HAS BEEN REPLACED WITH A FLOOD WARNING...

Please continue to heed road closures.

LAT...LON 4027 7448 4034 7463 4042 7459 4049 7446
      4056 7453 4058 7451 4060 7422 4056 7422
      4050 7428 4047 7427 4044 7421 4046 7414
      4041 7402 4033 7401 4022 7408 4024 7449
      4024 7448

$$

CMS

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 21, 9:35 PM EDT	Areal Flood Advisory	PHI	Mercer, Middlesex, Monmouth, Ocean	3 hr
Aug 21, 10:47 PM EDT	Areal Flood Advisory	PHI	Morris	3 hr
Aug 21, 11:38 PM EDT	Areal Flood Advisory	PHI	Atlantic, Burlington, Monmouth, Ocean	3 hr
Aug 22, 12:04 AM EDT	Areal Flood Advisory	PHI	Atlantic, Burlington, Camden, Monmouth, Ocean	3 hr
Aug 22, 12:24 AM EDT	Flash Flood Warning	PHI	Morris	3 hr
Aug 22, 1:30 AM EDT	Areal Flood Advisory	PHI	Middlesex, Monmouth	4 hr
Aug 22, 1:35 AM EDT	Areal Flood Advisory	PHI	Morris, Somerset	3 hr
Aug 22, 2:09 AM EDT	Flash Flood Warning	PHI	Burlington, Ocean	5 hr
Aug 22, 2:40 AM EDT	Flash Flood Warning	PHI	Hunterdon, Morris, Somerset	5 hr
Aug 22, 3:10 AM EDT	Flash Flood Warning	PHI	Burlington, Hunterdon, Mercer, Monmouth, Ocean	8 hr
Aug 22, 4:21 AM EDT	Flash Flood Warning	PHI	Monmouth, Ocean	3 hr
Aug 22, 5:36 AM EDT	Flash Flood Warning Considerable damage threat	PHI	Mercer, Middlesex, Monmouth, Somerset	5 hr
Aug 22, 6:07 AM EDT	Flash Flood Warning	PHI	Hunterdon, Warren	67 min
Aug 22, 7:52 AM EDT	Areal Flood Warning	PHI	Hunterdon, Somerset	15 hr
Aug 22, 10:43 AM EDT	Special Marine Warning	PHI		62 min
Aug 22, 10:49 AM EDT	Areal Flood Warning	PHI	Middlesex, Monmouth, Somerset	13 hr
Aug 22, 10:52 AM EDT	Areal Flood Warning	PHI	Hunterdon, Mercer, Monmouth	13 hr
Aug 22, 11:06 AM EDT	Special Marine Warning	PHI		54 min
Aug 22, 1:35 PM EDT	Coastal Flood Advisory	PHI	Cape May	10 hr
Aug 22, 1:53 PM EDT	Areal Flood Advisory	PHI	Morris	6 hr
Aug 22, 3:21 PM EDT	River Flood Warning	PHI	Somerset	54 hr
Aug 22, 5:07 PM EDT	Areal Flood Advisory	PHI	Morris, Sussex, Warren	6 hr
Aug 22, 5:48 PM EDT	Flash Flood Warning	PHI	Morris, Sussex, Warren	6 hr

Nearby

Flash Flood Warnings in New Jersey, 2021 Every flash flood warning in 2021

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.