Alert archive / New Jersey / Flash Flood Warnings in 2021

Flash Flood Warning 88, NWS Philadelphia/Mount Holly

September 23, 20215 counties in New Jersey

NWS Philadelphia/Mount Holly issued this flash flood warning at Sep 23, 2021, 4:36 PM EDT for 5 counties in New Jersey. It was in force for 3 hr. 10 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: Sep 23, 2021, 4:36 PM EDT (20:36 UTC)
Expired: Sep 23, 2021, 7:30 PM EDT
In force: 3 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

Counties Middlesex County, NJ, Monmouth County, NJ, Morris County, NJ, Somerset County, NJ, Sussex County, NJ

The radar

The Philadelphia radar (KDIX), 82 km from the middle of the area, began a volume at 20:39 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
Sep 23, 4:45 PM EDT	FLASH FLOOD	1 Sw New Brunswick, NJ	JERSEY AVENUE CLOSED BETWEEN TAILOR SQUARE AND SANDFORD STREET DUE TO FLOODING. TIME BASED ON DISPATCH REPORT.
Sep 23, 5:00 PM EDT	HEAVY RAIN 1.66	Bridgewater, NJ	1.64 INCHES OF RAIN WITHIN THE PAST 2 HOURS. FLOODING ON THE CHAMBERS BROOK IN BEDMINSTER AND BRIDGEWATER.
Sep 23, 5:02 PM EDT	FLOOD	1 Ne Morris Plains, NJ	FLOODING ON STATE HIGHWAY 10 NEAR U.S. HIGHWAY 202. LANE RESTRICTIONS IN PLACE. TIME BASED ON DISPATCH REPORT.
Sep 23, 5:08 PM EDT	FLOOD	2 Ssw Martinsville, NJ	FLOODING ON THE INTERSTATE 287 RAMP TO U.S. HIGHWAY 22. LANE RESTRICTIONS IN PLACE. TIME BASED ON DISPATCH REPORT.
Sep 23, 5:26 PM EDT	FLOOD	1 Nnw North Plainfield, NJ	FLOODING ON U.S. HIGHWAY 22 BETWEEN NORTH DRIVE AND WASHINGTON AVENUE. LANE RESTRICTIONS REQUIRED. TIME BASED ON DISPATCH REPORT.
Sep 23, 5:28 PM EDT	FLOOD	3 Ssw Bedminster Twp, NJ	FLOODING ON INTERSTATE 78 WEST OF EXIT 29 WITH LANE RESTRICTIONS. TIME BASED ON DISPATCH REPORT.
Sep 23, 5:33 PM EDT	FLOOD	Morristown, NJ	FLOODING ON INTERSTATE 287 NEAR EXIT 35. LANE RESTRICTIONS IN PLACE. TIME BASED ON DISPATCH REPORT.
Sep 23, 5:45 PM EDT	FLOOD	Metuchen, NJ	FLOODING ON MAIN STREET NEAR THE RAILROAD TRACKS. ROAD CLOSURES REQUIRED. TIME ESTIMATED FROM SOCIAL MEDIA REPORT.
Sep 23, 6:50 PM EDT	FLOOD	2 Wsw Manville, NJ	FLOODING ON U.S. HIGHWAY 206 NEAR CAMPLAIN ROAD. TIME BASED ON SOCIAL MEDIA REPORT.
Sep 23, 6:51 PM EDT	FLOOD	2 N Bridgewater, NJ	FLOODING ON THE EXPRESS LANES OF INTERSTATE 287 NEAR EXIT 21. TIME BASED ON DISPATCH REPORT.

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, 8.6 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-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: 103 J/kg
Mixed-layer CIN: -11 J/kg
Mixed-layer LCL: 687 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: 249 m²/s²
0-3 km storm-relative helicity: 201 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 1.1

Open this sounding in Storm Lab

The text

As transmitted.

135 
WGUS51 KPHI 232036
FFWPHI
NJC023-025-027-035-037-232330-
/O.NEW.KPHI.FF.W.0088.210923T2036Z-210923T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
436 PM EDT Thu Sep 23 2021

The National Weather Service in Mount Holly has issued a

* Flash Flood Warning for...
  Northwestern Monmouth County in central New Jersey...
  Middlesex County in northern New Jersey...
  Morris County in northern New Jersey...
  Somerset County in northern New Jersey...
  Southeastern Sussex County in northwestern New Jersey...

* Until 730 PM EDT.

* At 436 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 0.5 and 1.5 inches of 
  rain have fallen. 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, Morristown, Somerville, Sandy Hook, 
  Somerset, Edison, Middletown, Old Bridge, East Brunswick, 
  Bridgewater, and South Brunswick.

This includes the following highways...
	New Jersey Turnpike between exits 9 and 13.
	Interstate 78 in New Jersey between mile markers 28 and 42.
	Interstate 80 in New Jersey between mile markers 26 and 48.
	Interstate 287 in New Jersey between mile markers 0 and 49.
	Garden State Parkway between mile markers 110 and 134.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 4091 7472 4108 7450 4103 7450 4105 7445
      4091 7432 4086 7432 4074 7437 4067 7446
      4066 7440 4060 7446 4060 7422 4056 7422
      4049 7429 4046 7426 4040 7398 4048 7401
      4038 7395 4026 7447 4068 7472

FLASH FLOOD...RADAR INDICATED

$$

NC

2 follow-up statements

227 
WGUS71 KPHI 232138
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
538 PM EDT Thu Sep 23 2021

NJC023-025-027-035-037-232330-
/O.CON.KPHI.FF.W.0088.000000T0000Z-210923T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Middlesex NJ-Monmouth NJ-Morris NJ-Somerset NJ-Sussex NJ-
538 PM EDT Thu Sep 23 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 730 PM EDT THIS 
EVENING FOR NORTHWESTERN MONMOUTH, MIDDLESEX, MORRIS, SOMERSET, AND 
SOUTHEASTERN SUSSEX COUNTIES...

At 538 PM EDT, Doppler radar indicated thunderstorms producing heavy 
rain in Middlesex county. Between 1 and 2 inches of rain have 
fallen. Flash flooding is already occurring, with road closures 
noted in portions of Middlesex county.

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, Morristown, Somerville, Sandy Hook, 
  Somerset, Edison, Middletown, Old Bridge, East Brunswick, 
  Bridgewater, and South Brunswick.

This includes the following highways...
	New Jersey Turnpike between exits 9 and 13.
	Interstate 78 in New Jersey between mile markers 29 and 42.
	Interstate 80 in New Jersey between mile markers 26 and 48.
	Interstate 287 in New Jersey between mile markers 0 and 49.
	Garden State Parkway between mile markers 111 and 134.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4091 7472 4108 7450 4103 7450 4105 7445
      4091 7432 4086 7432 4074 7437 4067 7446
      4066 7440 4060 7446 4060 7422 4056 7422
      4049 7429 4046 7426 4040 7398 4048 7401
      4038 7395 4026 7447 4068 7472

FLASH FLOOD...RADAR INDICATED

$$

NC

719 
WGUS71 KPHI 232320
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
720 PM EDT Thu Sep 23 2021

NJC023-025-027-035-037-232330-
/O.EXP.KPHI.FF.W.0088.000000T0000Z-210923T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Middlesex NJ-Monmouth NJ-Morris NJ-Somerset NJ-Sussex NJ-
720 PM EDT Thu Sep 23 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 730 PM EDT THIS EVENING FOR 
NORTHWESTERN MONMOUTH, MIDDLESEX, MORRIS, SOMERSET, AND SOUTHEASTERN 
SUSSEX COUNTIES...

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

A Flash Flood Watch remains in effect until 500 AM EDT Friday for 
portions of central New Jersey...northern New Jersey...and northwest 
New Jersey.

LAT...LON 4091 7472 4108 7450 4103 7450 4105 7445
      4091 7432 4086 7432 4074 7437 4067 7446
      4066 7440 4060 7446 4060 7422 4056 7422
      4049 7429 4046 7426 4040 7398 4048 7401
      4038 7395 4026 7447 4068 7472

$$

NC

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 22, 8:43 PM EDT	Gale Warning	PHI		18 hr
Sep 23, 9:12 AM EDT	Coastal Flood Advisory	PHI	Burlington, Camden, Gloucester	10 hr
Sep 23, 11:33 AM EDT	Areal Flood Advisory	PHI	Cumberland, Gloucester, Salem	3 hr
Sep 23, 11:57 AM EDT	Flash Flood Warning	PHI	Gloucester, Salem	3 hr
Sep 23, 12:12 PM EDT	Severe Thunderstorm Warning	PHI	Gloucester, Salem	48 min
Sep 23, 12:54 PM EDT	Special Weather Statement	PHI	Gloucester	51 min
Sep 23, 12:56 PM EDT	Areal Flood Advisory	PHI	Burlington, Camden, Hunterdon, Mercer, Warren	3 hr
Sep 23, 1:13 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Camden, Gloucester, Salem	47 min
Sep 23, 1:42 PM EDT	Flash Flood Warning	PHI	Burlington, Camden, Gloucester	4 hr
Sep 23, 1:58 PM EDT	Special Weather Statement	PHI	Camden, Hunterdon	32 min
Sep 23, 2:37 PM EDT	Areal Flood Advisory	PHI	Burlington, Hunterdon, Mercer, Middlesex, Monmouth, Morris and 3 more	3 hr
Sep 23, 2:47 PM EDT	Special Weather Statement	PHI	Hunterdon, Mercer	28 min
Sep 23, 2:52 PM EDT	Special Weather Statement	PHI	Camden	23 min
Sep 23, 3:13 PM EDT	Special Weather Statement	PHI	Mercer, Somerset	32 min
Sep 23, 3:16 PM EDT	Special Weather Statement	PHI	Burlington	29 min
Sep 23, 3:23 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Mercer, Middlesex, Morris, Somerset	52 min
Sep 23, 3:26 PM EDT	Flash Flood Warning	PHI	Burlington, Hunterdon, Mercer, Middlesex, Morris, Somerset	2 hr
Sep 23, 3:50 PM EDT	Special Weather Statement	PHI	Burlington	25 min
Sep 23, 4:21 PM EDT	Areal Flood Advisory	PHI	Middlesex, Monmouth, Morris, Ocean, Somerset, Sussex	15 min
Sep 23, 5:00 PM EDT	Special Weather Statement	PHI	Monmouth	30 min

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.