Alert archive / New Jersey / Flash Flood Warnings in 2021

Flash Flood Warning 31, NWS Philadelphia/Mount Holly

July 29, 2021Monmouth County, Ocean County, New Jersey

NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 29, 2021, 8:43 PM EDT for Monmouth County, Ocean County, New Jersey. It was in force for 3 hr. 3 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 29, 2021, 8:43 PM EDT (00:43 UTC)
Expired
Jul 30, 2021, 12:00 AM EDT
In force
3 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

Counties Monmouth County, NJ, Ocean County, NJ

The radar

The Philadelphia radar (KDIX), 30 km from the middle of the area, began a volume at 00:43 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 29, 8:45 PM EDTFLASH FLOOD1 Sw Wanamassa, NJNJ ROUTE 35 CLOSED AT NJ ROUTE 66 IN NEPTUNE TOWNSHIP.
Jul 29, 8:45 PM EDTFLASH FLOODManasquan, NJNJ ROUTE 71 CLOSED DUE TO FLOODING NEAR MAIN STREET.
Jul 29, 8:50 PM EDTFLASH FLOOD1 Wnw Lake Como, NJNJ ROUTE 35 CLOSED AT BELMAR BOULEVARD IN BELMAR.

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, 0.7 hours before the alert went out and 137 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 00:00Z on 2021-07-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 635 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 00:00Z on 2021-07-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 381 square meters per square second.19395878Sfc1 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
635 J/kg
Mixed-layer CIN
-2 J/kg
Mixed-layer LCL
502 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
381 m²/s²
0-3 km storm-relative helicity
515 m²/s²
Significant tornado parameter
1.3
Supercell composite
5.0

Open this sounding in Storm Lab

The text

As transmitted.

870 
WGUS51 KPHI 300043
FFWPHI
NJC025-029-300445-
/O.NEW.KPHI.FF.W.0031.210730T0043Z-210730T0445Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
843 PM EDT Thu Jul 29 2021

The National Weather Service in Mount Holly has issued a

* Flash Flood Warning for...
  Southeastern Monmouth County in central New Jersey...
  Northeastern Ocean County in southern New Jersey...

* Until 1245 AM EDT.

* At 843 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 2 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 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 will experience flash flooding include...
  Toms River, Asbury Park, Lakewood, Howell, Tinton Falls, 
  Manasquan, Point Pleasant Beach, Seaside Heights, Farmingdale, 
  Mantoloking, Allenwood, and Brick Township.

This includes the following highways...
	Interstate 195 in New Jersey between mile markers 29 and 34.
	Garden State Parkway between mile markers 85 and 104.

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.

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

Be aware of your surroundings and do not drive on flooded roads.

Please report observed flooding to local emergency services or law 
enforcement and request they pass this information to the National 
Weather Service when you can do so safely.

&&

LAT...LON 4003 7431 4027 7415 4020 7385 3991 7396

FLASH FLOOD...RADAR INDICATED

$$

MPS
2 follow-up statements
641 
WGUS71 KPHI 300258
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
1058 PM EDT Thu Jul 29 2021

NJC025-029-300445-
/O.CON.KPHI.FF.W.0031.000000T0000Z-210730T0445Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Monmouth NJ-Ocean NJ-
1058 PM EDT Thu Jul 29 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1245 AM EDT FRIDAY 
FOR SOUTHEASTERN MONMOUTH AND NORTHEASTERN OCEAN COUNTIES...

At 1058 PM EDT, Doppler radar indicated thunderstorms produced heavy 
rain across the warned area. Between 1 and 3 inches of rain have 
fallen. Flash flooding is ongoing.

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 will experience flash flooding include...
  Toms River, Asbury Park, Lakewood, Howell, Tinton Falls, 
  Manasquan, Point Pleasant Beach, Seaside Heights, Farmingdale, 
  Mantoloking, Allenwood, and Brick Township.

This includes the following highways...
	Interstate 195 in New Jersey between mile markers 29 and 34.
	Garden State Parkway between mile markers 85 and 104.

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.

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

Be aware of your surroundings and do not drive on flooded roads.

Please report observed flooding to local emergency services or law 
enforcement and request they pass this information to the National 
Weather Service when you can do so safely.

&&

LAT...LON 4003 7431 4027 7415 4020 7385 3991 7396

FLASH FLOOD...RADAR INDICATED

$$

MPS
075 
WGUS71 KPHI 300400
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
1200 AM EDT Fri Jul 30 2021

NJC025-029-300410-
/O.CAN.KPHI.FF.W.0031.000000T0000Z-210730T0445Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Monmouth NJ-Ocean NJ-
1200 AM EDT Fri Jul 30 2021

...FLASH FLOOD WARNING IS CANCELLED FOR SOUTHEASTERN MONMOUTH AND 
NORTHEASTERN OCEAN 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.

LAT...LON 4003 7431 4027 7415 4020 7385 3991 7396

$$

MPS

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 29, 8:03 PM EDTSevere Thunderstorm WarningPHIBurlington, Monmouth, Ocean57 min
Jul 29, 8:03 PM EDTTornado WarningPHIOcean27 min
Jul 29, 8:19 PM EDTFlash Flood WarningPHIBurlington, Monmouth, Ocean4 hr
Jul 29, 8:39 PM EDTTornado WarningPHIBurlington, Ocean51 min
Jul 29, 8:42 PM EDTTornado WarningPHIMonmouth19 min
Jul 29, 9:15 PM EDTSpecial Marine WarningPHI2 hr

Nearby

Flash Flood Warnings in New Jersey, 2021Every 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.