Alert archive / New Jersey / Flash Flood Warnings in 2021

Flash Flood Warning 13, NWS Philadelphia/Mount Holly

July 2, 2021Burlington County, Camden County, New Jersey; Philadelphia County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 2, 2021, 7:41 PM EDT for Burlington County, Camden County, New Jersey; Philadelphia County, Pennsylvania. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jul 2, 2021, 7:41 PM EDT (23:41 UTC)
Expired
Jul 2, 2021, 10:45 PM EDT
In force
3 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

Counties Burlington County, NJ, Camden County, NJ, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 54 km from the middle of the area, began a volume at 23:42 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.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 11.7 hours before the alert went out and 209 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 12:00Z on 2021-07-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 51 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 12:00Z on 2021-07-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 11 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
51 J/kg
Mixed-layer CIN
-35 J/kg
Mixed-layer LCL
836 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
11 m²/s²
0-3 km storm-relative helicity
28 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.1

Open this sounding in Storm Lab

The text

As transmitted.

126 
WGUS51 KPHI 022341
FFWPHI
NJC005-007-PAC101-030245-
/O.NEW.KPHI.FF.W.0013.210702T2341Z-210703T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
741 PM EDT Fri Jul 2 2021

The National Weather Service in Mount Holly has issued a

* Flash Flood Warning for...
  Northwestern Burlington County in southern New Jersey...
  Northwestern Camden County in southern New Jersey...
  South Central Philadelphia County in southeastern Pennsylvania...

* Until 1045 PM EDT.

* At 741 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 0.5 and 1 inch of rain 
  has fallen. Additional rainfall amounts of 0.5 to 1 inch are 
  possible in the warned area, which will be sufficient to cause 
  flash flooding in this urbanized 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...
  Philadelphia, Camden, Gloucester City, Willingboro, Bellmawr, 
  Riverside, Palmyra, Beverly, Audubon Park, Cherry Hill Mall, 
  Golden Triangle, and Erlton-Ellisburg.

This includes the following highways...
	Interstate 95 in Pennsylvania near mile marker 20.
	Interstate 76 in New Jersey between mile markers 1 and 3.
	Interstate 295 in New Jersey near mile marker 46.
	Interstate 676 in New Jersey between mile markers 0 and 4.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3993 7516 3999 7506 4007 7493 4002 7484
      3987 7509

FLASH FLOOD...RADAR INDICATED

$$

JEO
2 follow-up statements
343 
WGUS71 KPHI 030109
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
909 PM EDT Fri Jul 2 2021

NJC005-007-PAC101-030245-
/O.CON.KPHI.FF.W.0013.000000T0000Z-210703T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Burlington NJ-Camden NJ-Philadelphia PA-
909 PM EDT Fri Jul 2 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1045 PM EDT THIS 
EVENING FOR NORTHWESTERN BURLINGTON, NORTHWESTERN CAMDEN, AND SOUTH 
CENTRAL PHILADELPHIA COUNTIES...

At 909 PM EDT, Doppler radar and automated rain gauges indicated 
thunderstorms producing heavy rain across the warned area. Between 1 
and 1.5 inches of rain have fallen. Additional rainfall amounts up 
to 0.5 inches are possible in the warned area. Flash flooding is 
ongoing or expected to begin shortly.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar and automated gauges.

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...
  Philadelphia, Camden, Gloucester City, Willingboro, Bellmawr, 
  Riverside, Palmyra, Beverly, Audubon Park, Cherry Hill Mall, 
  Golden Triangle, and Erlton-Ellisburg.

This includes the following highways...
	Interstate 95 in Pennsylvania near mile marker 20.
	Interstate 76 in New Jersey between mile markers 1 and 3.
	Interstate 676 in New Jersey between mile markers 0 and 4.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3993 7516 3999 7506 4007 7493 4002 7484
      3987 7509

FLASH FLOOD...RADAR AND GAUGE INDICATED

$$

JEO
871 
WGUS71 KPHI 030236
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
1036 PM EDT Fri Jul 2 2021

NJC005-007-PAC101-030246-
/O.EXP.KPHI.FF.W.0013.000000T0000Z-210703T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Burlington NJ-Camden NJ-Philadelphia PA-
1036 PM EDT Fri Jul 2 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 1045 PM EDT THIS EVENING FOR 
NORTHWESTERN BURLINGTON, NORTHWESTERN CAMDEN, AND SOUTH CENTRAL 
PHILADELPHIA 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 3993 7516 3999 7506 4007 7493 4002 7484
      3987 7509

$$

JEO

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 1, 11:31 PM EDTSpecial Weather StatementPHISalem29 min
Jul 1, 11:40 PM EDTSevere Thunderstorm WarningPHIAtlantic, Cumberland, Gloucester, Salem39 min
Jul 2, 4:31 AM EDTAreal Flood WarningPHICumberland6 hr
Jul 2, 10:40 AM EDTAreal Flood WarningPHICumberland6 hr
Jul 2, 11:16 AM EDTAreal Flood AdvisoryPHIBurlington, Camden, Gloucester119 min
Jul 2, 12:12 PM EDTAreal Flood AdvisoryPHIGloucester, Salem97 min
Jul 2, 1:11 PM EDTFlash Flood WarningPHIGloucester, Salem59 min
Jul 2, 1:47 PM EDTAreal Flood AdvisoryPHIAtlantic, Burlington, Camden, Gloucester, Ocean, Salem116 min
Jul 2, 3:48 PM EDTSmall Craft AdvisoryPHI31 hr
Jul 2, 4:47 PM EDTSpecial Weather StatementPHISussex28 min
Jul 2, 6:42 PM EDTSpecial Weather StatementPHIWarren48 min
Jul 2, 6:53 PM EDTSevere Thunderstorm WarningPHIMorris, Sussex, Warren52 min
Jul 2, 7:25 PM EDTSevere Thunderstorm WarningPHIMorris, Sussex, Warren50 min
Jul 2, 7:33 PM EDTSpecial Weather StatementPHICumberland42 min
Jul 2, 4:54 PM EDTFlash Flood WarningPHIMontgomery, Philadelphia5 hr
Jul 2, 5:29 PM EDTSpecial Weather StatementPHICarbon46 min
Jul 2, 5:44 PM EDTSevere Thunderstorm WarningPHICarbon, Lehigh, Monroe, Northampton46 min

Nearby

Flash Flood Warnings in New Jersey, 2021Flash Flood Warnings in Pennsylvania, 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.