Alert archive / New Jersey / Flash Flood Warnings in 2021

Flash Flood Warning 25, NWS Philadelphia/Mount Holly

July 17, 20215 counties in New Jersey

NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 17, 2021, 10:43 PM EDT for 5 counties in New Jersey. It was in force for 79 min. 1 report 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 17, 2021, 10:43 PM EDT (02:43 UTC)
Expired: Jul 18, 2021, 12:02 AM EDT
In force: 79 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

Counties Burlington County, NJ, Mercer County, NJ, Middlesex County, NJ, Monmouth County, NJ, Ocean County, NJ

The radar

The Philadelphia radar (KDIX), 38 km from the middle of the area, began a volume at 02:44 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
Jul 17, 11:00 PM EDT	FLASH FLOOD	1 Ese Jacksonville, NJ	WARNER ROAD JUST WEST OF THE FAIRGROUNDS WAS FLOODED AND IMPASSABLE. THE ROAD REMAINED CLOSED THE NEXT DAY. TIME ESTIMATED FROM RADAR.

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, 2.7 hours before the alert went out and 151 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: 1431 J/kg
Mixed-layer CIN: -48 J/kg
Mixed-layer LCL: 988 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: 26 m²/s²
0-3 km storm-relative helicity: 54 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.6

Open this sounding in Storm Lab

The text

As transmitted.

706 
WGUS51 KPHI 180243
FFWPHI
NJC005-021-023-025-029-180600-
/O.NEW.KPHI.FF.W.0025.210718T0243Z-210718T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
1043 PM EDT Sat Jul 17 2021

The National Weather Service in Mount Holly has issued a

* Flash Flood Warning for...
  Southeastern Mercer County in central New Jersey...
  Monmouth County in central New Jersey...
  Middlesex County in northern New Jersey...
  Burlington County in southern New Jersey...
  Northwestern Ocean County in southern New Jersey...

* Until 200 AM EDT.

* At 1043 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 1.5 inches of 
  rain have already fallen in spots. 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.

  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...
  Toms River, New Brunswick, Perth Amboy, Long Branch, Asbury Park, 
  Sandy Hook, Edison, Lakewood, Middletown, Old Bridge, and Jackson.

This includes the following highways...
	New Jersey Turnpike between exits 4 and 13.
	Interstate 295 in New Jersey between mile markers 36 and 59.
	Interstate 195 in New Jersey between mile markers 1 and 34.
	Interstate 287 in New Jersey between mile markers 0 and 10.
	Garden State Parkway between mile markers 88 and 134.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4028 7460 4034 7466 4049 7446 4056 7453
      4058 7451 4060 7422 4056 7422 4050 7428
      4046 7426 4040 7398 4048 7401 4042 7394
      4010 7401 3978 7480 3978 7490 3989 7493
      3999 7506 4013 7482 4014 7474

FLASH FLOOD...RADAR INDICATED

$$

Iovino

1 follow-up statement

279 
WGUS71 KPHI 180402
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
1202 AM EDT Sun Jul 18 2021

NJC005-021-023-025-029-180412-
/O.CAN.KPHI.FF.W.0025.000000T0000Z-210718T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Burlington NJ-Mercer NJ-Middlesex NJ-Monmouth NJ-Ocean NJ-
1202 AM EDT Sun Jul 18 2021

...FLASH FLOOD WARNING IS CANCELLED FOR SOUTHEASTERN MERCER, 
MONMOUTH, MIDDLESEX, BURLINGTON, AND NORTHWESTERN OCEAN COUNTIES...

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 200 AM EDT for portions 
of central New Jersey...northern New Jersey...northwest New Jersey...
and southern New Jersey.

LAT...LON 4028 7460 4034 7466 4049 7446 4056 7453
      4058 7451 4060 7422 4056 7422 4050 7428
      4046 7426 4040 7398 4048 7401 4042 7394
      4010 7401 3978 7480 3978 7490 3989 7493
      3999 7506 4013 7482 4014 7474

$$

Iovino

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 17, 8:00 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Camden, Mercer, Monmouth	45 min
Jul 17, 8:09 PM EDT	Flash Flood Warning	PHI	Mercer, Somerset	4 hr
Jul 17, 8:35 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Burlington, Camden, Gloucester	40 min
Jul 17, 8:36 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Mercer, Middlesex, Monmouth, Ocean, Somerset	54 min
Jul 17, 8:46 PM EDT	Special Marine Warning	PHI		59 min
Jul 17, 8:53 PM EDT	Areal Flood Advisory	PHI	Mercer, Middlesex, Monmouth	3 hr
Jul 17, 9:25 PM EDT	Areal Flood Advisory	PHI	Burlington, Camden, Gloucester, Salem	2 hr
Jul 17, 9:27 PM EDT	Severe Thunderstorm Warning	PHI	Gloucester, Salem	48 min
Jul 17, 9:30 PM EDT	Severe Thunderstorm Warning	PHI	Cape May	29 min
Jul 17, 9:36 PM EDT	Flash Flood Warning	PHI	Camden, Gloucester, Salem	2 hr
Jul 17, 9:44 PM EDT	Special Marine Warning	PHI		61 min
Jul 17, 9:48 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Camden, Gloucester, Mercer, Salem	42 min
Jul 17, 10:21 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Mercer, Middlesex, Monmouth, Ocean	54 min
Jul 17, 10:22 PM EDT	Tornado Warning	PHI	Burlington, Monmouth, Ocean	23 min
Jul 17, 10:27 PM EDT	Special Weather Statement	PHI	Burlington, Camden	33 min
Jul 17, 10:38 PM EDT	Tornado Warning	PHI	Burlington, Monmouth, Ocean	16 min
Jul 17, 10:47 PM EDT	Special Marine Warning	PHI		118 min
Jul 17, 10:51 PM EDT	Special Marine Warning	PHI		114 min
Jul 17, 11:07 PM EDT	Special Weather Statement	PHI	Middlesex	38 min
Jul 17, 11:08 PM EDT	Areal Flood Warning	PHI	Hunterdon	12 hr
Jul 17, 11:11 PM EDT	Special Weather Statement	PHI	Monmouth, Ocean	34 min
Jul 17, 11:20 PM EDT	Special Marine Warning	PHI		115 min
Jul 17, 11:26 PM EDT	Areal Flood Warning	PHI	Somerset	10 hr
Jul 18, 2:41 AM EDT	Areal Flood Warning	PHI	Mercer	4 hr
Jul 18, 3:48 AM EDT	River Flood Warning	PHI	Mercer	3 hr
Jul 18, 9:08 AM EDT	Areal Flood Warning	PHI	Somerset	2 hr
Jul 18, 11:03 AM EDT	River Flood Warning	PHI	Middlesex, Somerset	88 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.