Alert archive / New Jersey / Flash Flood Warnings in 2021

Flash Flood Warning 63, NWS Philadelphia/Mount Holly

August 29, 2021Atlantic County, Cape May County, New Jersey

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 29, 2021, 12:37 PM EDT for Atlantic County, Cape May County, New Jersey. It was in force for 4 hr. 21 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 29, 2021, 12:37 PM EDT (16:37 UTC)
Expired
Aug 29, 2021, 4:45 PM EDT
In force
4 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

Counties Atlantic County, NJ, Cape May County, NJ

The radar

The Philadelphia radar (KDIX), 74 km from the middle of the area, began a volume at 16:37 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
Aug 29, 1:20 PM EDTFLOODSomers Point, NJROAD FLOODING REPORTED. WATER DEEPER THAN 1 FOOT IN SOME AREAS. TIME ESTIMATED.
Aug 29, 1:20 PM EDTFLASH FLOODSomers Point, NJCORRECTS PREVIOUS FLOOD REPORT FROM SOMERS POINT. ROAD FLOODING REPORTED. WATER DEEPER THAN 1 FOOT IN SOME AREAS. TIME ESTIMATED.
Aug 29, 1:30 PM EDTFLOOD2 Ese Marmora, NJROAD FLOODING REPORTED NEAR 32ND STREET IN OCEAN CITY. WATER DEEPER THAN 1 FOOT IN SOME LOCATIONS. TIME ESTIMATED.
Aug 29, 1:30 PM EDTFLASH FLOOD2 Ese Marmora, NJWATER UP TO 8 INCHES DEEP OVER THE ROAD AT THE INTERSECTION OF 34TH STREET AND BAY AVENUE. FIRST OBSERVED AT 1:30 PM. STILL FLOODED AT 3:15 PM.
Aug 29, 1:30 PM EDTFLASH FLOOD2 Ese Marmora, NJCORRECTS PREVIOUS FLOOD REPORT FROM 2 ESE MARMORA. ROAD FLOODING REPORTED NEAR 32ND STREET IN OCEAN CITY. WATER DEEPER THAN 1 FOOT IN SOME LOCATIONS. TIME ESTIMATED.
Aug 29, 1:30 PM EDTHEAVY RAIN 2.51Ocean City, NJMESONET STATION FW2611 OCEAN CITY.
Aug 29, 2:00 PM EDTFLASH FLOOD1 Wsw Ocean City, NJMULTIPLE ROADS CLOSED AROUND 16TH STREET IN OCEAN CITY DUE TO HIGH WATER.
Aug 29, 2:00 PM EDTHEAVY RAIN 4.381 Ne Ocean City, NJSTATION KNJOCEAN143.
Aug 29, 2:05 PM EDTHEAVY RAIN 2.18Somers Point, NJRAINFALL SINCE 7 AM.
Aug 29, 2:05 PM EDTHEAVY RAIN 3.32Beesleys Point, NJSTATION KNJBEESL3.
Aug 29, 2:05 PM EDTHEAVY RAIN 3.352 Se Marmora, NJSTATION KNJOCEAN95.
Aug 29, 2:05 PM EDTHEAVY RAIN 4.311 Sw Ocean City, NJSTATION KNJOCEAN111.
Aug 29, 2:10 PM EDTHEAVY RAIN 4.312 Wsw Ocean City, NJ2.0 INCHES OF RAIN SINCE 12:30 PM.
Aug 29, 3:00 PM EDTFLASH FLOOD2 Ese Marmora, NJNUMEROUS ROADS FLOODED WEST OF ASBURY AVENUE IN OCEAN CITY. THE HAVEN AVENUE BASIN ROADS ARE ONLY PASSABLE BY HIGH WATER CLEARANCE MILITARY VEHICLES.
Aug 29, 3:00 PM EDTHEAVY RAIN 3.082 Se Marmora, NJ
Aug 29, 3:15 PM EDTHEAVY RAIN 3.53Beesleys Point, NJSTATION KNJBEESL3.
Aug 29, 3:15 PM EDTHEAVY RAIN 3.912 Se Marmora, NJSTATION KNJOCEAN95.
Aug 29, 3:15 PM EDTHEAVY RAIN 4.441 Sw Ocean City, NJSTATION KNJOCEAN111.
Aug 29, 3:20 PM EDTHEAVY RAIN 2.411 Sw Marmora, NJSTATION KNJMARMO4.
Aug 29, 3:20 PM EDTHEAVY RAIN 3.7Ocean City, NJSTATION KNJOCEAN152.
Aug 29, 4:00 PM EDTFLASH FLOOD2 Ese Marmora, NJMANY ROADS AROUND HAVEN AVENUE ARE NOT PASSABLE. HIGH WATER RESCUES AND CARS SUBMERGED HAVE BEEN REPORTED.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 12:00Z, 4.6 hours before the alert went out and 168 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, Wallops Is Stn, VA at 12:00Z on 2021-08-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 87 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, Wallops Is Stn, VA at 12:00Z on 2021-08-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -36 square meters per square second.1939Sfc1 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
87 J/kg
Mixed-layer CIN
-120 J/kg
Mixed-layer LCL
568 m above ground
0-6 km bulk shear
5 kt
0-1 km storm-relative helicity
-36 m²/s²
0-3 km storm-relative helicity
-11 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

405 
WGUS51 KPHI 291637
FFWPHI
NJC001-009-292045-
/O.NEW.KPHI.FF.W.0063.210829T1637Z-210829T2045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
1237 PM EDT Sun Aug 29 2021

The National Weather Service in Mount Holly has issued a

* Flash Flood Warning for...
  Southeastern Atlantic County in southern New Jersey...
  Northeastern Cape May County in southern New Jersey...

* Until 445 PM EDT.

* At 1237 PM EDT, trained weather spotters reported heavy rain in 
  Ocean City New Jersey. Between 1 and 2.5 inches of rain have 
  fallen. The expected rainfall rate is 1 to 2 inches in 1 hour. 
  Additional rainfall amounts of 1 to 2.5 inches are possible in the 
  warned area. Flash flooding is already occurring.

  HAZARD...Flash flooding caused by heavy rain.

  SOURCE...Trained spotters 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...
  Ocean City, Somers Point, Margate City, Longport, Corbin City, 
  Beesleys Point, Marmora, and Linwood.

This includes the following highways...
	Garden State Parkway between mile markers 24 and 27...and
	between mile markers 29 and 30...and
	near mile marker 32.

The high tide is ongoing now which will exacerbate any heavy rain 
flash flooding.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3935 7461 3935 7458 3933 7452 3932 7450
      3931 7447 3921 7461 3923 7464 3924 7468

FLASH FLOOD...OBSERVED
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR

$$

SFJ
3 follow-up statements
817 
WGUS71 KPHI 291804
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
204 PM EDT Sun Aug 29 2021

NJC001-009-292045-
/O.CON.KPHI.FF.W.0063.000000T0000Z-210829T2045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Atlantic NJ-Cape May NJ-
204 PM EDT Sun Aug 29 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 445 PM EDT THIS 
AFTERNOON FOR SOUTHEASTERN ATLANTIC AND NORTHEASTERN CAPE MAY 
COUNTIES...

At 204 PM EDT, trained weather spotters reported heavy rain in Ocean 
City New Jersey. Between 2 and 4 inches of rain have fallen. The 
expected rainfall rate is 1 to 1.5 inches in 1 hour. Additional 
rainfall amounts of 0.5 to 1.5 inches are possible in the warned 
area. Flash flooding is already occurring.

HAZARD...Flash flooding caused by heavy rain.

SOURCE...Trained spotters 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...
  Ocean City, Somers Point, Margate City, Longport, Corbin City, 
  Beesleys Point, Marmora, and Linwood.

This includes the following highways...
	Garden State Parkway between mile markers 24 and 27...and
	between mile markers 29 and 30...and
	near mile marker 32.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3935 7461 3935 7458 3933 7452 3932 7450
      3931 7447 3921 7461 3923 7464 3924 7468

FLASH FLOOD...OBSERVED
EXPECTED RAINFALL...1-1.5 INCHES IN 1 HOUR

$$

SFJ
192 
WGUS71 KPHI 291930
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
330 PM EDT Sun Aug 29 2021

NJC001-009-292045-
/O.CON.KPHI.FF.W.0063.000000T0000Z-210829T2045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Atlantic NJ-Cape May NJ-
330 PM EDT Sun Aug 29 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 445 PM EDT THIS 
AFTERNOON FOR SOUTHEASTERN ATLANTIC AND NORTHEASTERN CAPE MAY 
COUNTIES...

At 330 PM EDT, trained weather spotters reported flash flooding in 
Ocean City New Jersey. Between 2 and 4.5 inches of rain have fallen. 
The expected rainfall rate is 0.5 to 1 inch in 1 hour. Additional 
rainfall amounts up to 1 inch are possible in the warned area. Flash 
flooding is already occurring.

HAZARD...Flash flooding caused by heavy rain.

SOURCE...Trained spotters 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...
  Ocean City, Somers Point, Margate City, Longport, Corbin City, 
  Beesleys Point, Marmora, and Linwood.

This includes the following highways...
	Garden State Parkway between mile markers 24 and 27...and
	between mile markers 29 and 30...and
	near mile marker 32.

Although the heaviest rain has ended, it will take time for waters 
to recede so any additional rain, even light rain, will exacerbate 
ongoing flooding.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3935 7461 3935 7458 3933 7452 3932 7450
      3931 7447 3921 7461 3923 7464 3924 7468

FLASH FLOOD...OBSERVED
EXPECTED RAINFALL...0.5-1 INCH IN 1 HOUR

$$

SFJ
521 
WGUS71 KPHI 292044
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
444 PM EDT Sun Aug 29 2021

NJC001-009-292054-
/O.EXP.KPHI.FF.W.0063.000000T0000Z-210829T2045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Atlantic NJ-Cape May NJ-
444 PM EDT Sun Aug 29 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 445 PM EDT THIS AFTERNOON FOR 
SOUTHEASTERN ATLANTIC AND NORTHEASTERN CAPE MAY 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 3935 7461 3935 7458 3933 7452 3932 7450
      3931 7447 3921 7461 3923 7464 3924 7468

$$

Gorse

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 29, 11:20 AM EDTAreal Flood AdvisoryPHIAtlantic, Cape May3 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.