Alert archive / Pennsylvania / Flash Flood Warnings in 2021

Flash Flood Warning 3, NWS Philadelphia/Mount Holly

June 3, 2021Camden County, Gloucester County, Salem County, New Jersey; New Castle County, Delaware; 4 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Jun 3, 2021, 7:09 PM EDT for Camden County, Gloucester County, Salem County, New Jersey; New Castle County, Delaware; 4 counties in Pennsylvania. It was in force for 2 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
Jun 3, 2021, 7:09 PM EDT (23:09 UTC)
Expired
Jun 3, 2021, 9:11 PM EDT
In force
2 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

Counties New Castle County, DE, Camden County, NJ, Gloucester County, NJ, Salem County, NJ, Chester County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Dover AFB radar (KDOX), 114 km from the middle of the area, began a volume at 23:11 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
Jun 3, 7:25 PM EDTFLOOD1 Ene Media, PAFLOODING REPORTED ALONG 476 IN DELAWARE COUNTY.
Jun 3, 8:34 PM EDTFLOOD1 Nne Rittenhouse Squar, PAFLOODING REPORTED ALONG INTERSTATE 676.
Jun 3, 8:34 PM EDTFLOOD1 N Rittenhouse Square, PACORRECTS PREVIOUS FLOOD REPORT FROM 1 NNE RITTENHOUSE SQUARE. FLOODING REPORTED ALONG INTERSTATE 676.

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

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 11.2 hours before the alert went out and 170 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, Washington/Dulle, VA at 12:00Z on 2021-06-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 73 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, Washington/Dulle, VA at 12:00Z on 2021-06-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 116 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
73 J/kg
Mixed-layer CIN
-52 J/kg
Mixed-layer LCL
511 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
116 m²/s²
0-3 km storm-relative helicity
118 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

As transmitted.

884 
WGUS51 KPHI 032309
FFWPHI
DEC003-NJC007-015-033-PAC029-045-091-101-040300-
/O.NEW.KPHI.FF.W.0003.210603T2309Z-210604T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
709 PM EDT Thu Jun 3 2021

The National Weather Service in Mount Holly has issued a

* Flash Flood Warning for...
  Northern New Castle County in northern Delaware...
  Northwestern Camden County in southern New Jersey...
  Northwestern Gloucester County in southern New Jersey...
  Northwestern Salem County in southern New Jersey...
  Southern Chester County in southeastern Pennsylvania...
  Delaware County in southeastern Pennsylvania...
  Southeastern Montgomery County in southeastern Pennsylvania...
  Philadelphia County in southeastern Pennsylvania...

* Until 1100 PM EDT.

* At 709 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. 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, Wilmington, Newark, West Chester, Chester, 
  Pennsville, Yeadon, Westtown, Carneys Point, Conshohocken, and 
  Palmyra.

This includes the following highways...
	Pennsylvania Turnpike between mile markers 335 and 338.
	Interstate 95 in Pennsylvania between mile markers 0 and 27.
	Interstate 95 in Delaware between mile markers 0 and 23.
	Interstate 76 in Pennsylvania between mile markers 330 and 351.
	Interstate 295 in New Jersey between mile markers 0 and 15.
	Interstate 676 in Pennsylvania between mile markers 0 and 1.
	Interstate 676 in New Jersey between mile markers 2 and 4.
	Interstate 476 in Pennsylvania between mile markers 0 and 19.

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 3972 7611 3973 7609 3974 7610 3976 7608
      3976 7606 3980 7604 3980 7605 3981 7603
      3983 7604 3983 7602 3985 7602 3984 7589
      4014 7521 4001 7505 3999 7506 4000 7504
      3998 7502 3957 7564 3962 7579 3972 7579

FLASH FLOOD...RADAR INDICATED

$$

NC
1 follow-up statement
008 
WGUS71 KPHI 040111
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
911 PM EDT Thu Jun 3 2021

DEC003-NJC007-015-033-PAC029-045-091-101-040121-
/O.CAN.KPHI.FF.W.0003.000000T0000Z-210604T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle DE-Camden NJ-Gloucester NJ-Salem NJ-Chester PA-Delaware
PA-Montgomery PA-Philadelphia PA-
911 PM EDT Thu Jun 3 2021

...FLASH FLOOD WARNING IS CANCELLED FOR NORTHERN NEW CASTLE, 
NORTHWESTERN CAMDEN, NORTHWESTERN GLOUCESTER, NORTHWESTERN SALEM, 
SOUTHERN CHESTER, DELAWARE, SOUTHEASTERN MONTGOMERY, AND 
PHILADELPHIA 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 1000 PM EDT for portions 
of northern Delaware...southern New Jersey...and southeast 
Pennsylvania.

LAT...LON 3972 7611 3973 7609 3974 7610 3976 7608
      3976 7606 3980 7604 3980 7605 3981 7603
      3983 7604 3983 7602 3985 7602 3984 7589
      4014 7521 4001 7505 3999 7506 4000 7504
      3998 7502 3957 7564 3962 7579 3972 7579

$$

NC

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 3, 9:37 AM EDTFlash Flood WatchPHIBurlington, Camden, Gloucester, Salem12 hr
Jun 3, 5:55 PM EDTSpecial Marine WarningPHI65 min
Jun 3, 6:33 PM EDTSevere Thunderstorm WarningPHIAtlantic, Cape May, Cumberland, Salem42 min
Jun 3, 7:07 PM EDTSevere Thunderstorm WarningPHIAtlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and 2 more38 min
Jun 3, 7:13 PM EDTAreal Flood AdvisoryPHIBurlington, Hunterdon, Mercer, Middlesex, Somerset3 hr
Jun 3, 7:52 PM EDTSevere Thunderstorm WarningPHIBurlington, Ocean38 min
Jun 3, 5:20 PM EDTAreal Flood AdvisoryPHINew Castle3 hr
Jun 3, 5:33 PM EDTSpecial Weather StatementPHISussex42 min
Jun 3, 3:02 PM EDTSpecial Weather StatementPHIBerks43 min
Jun 3, 3:54 PM EDTSpecial Weather StatementPHIBerks36 min
Jun 3, 5:14 PM EDTSevere Thunderstorm WarningPHIBerks, Chester27 min
Jun 3, 5:59 PM EDTFlash Flood WarningPHIBerks, Chester108 min
Jun 3, 6:19 PM EDTFlash Flood WarningPHIBerks, Chester, Montgomery115 min

Nearby

Flash Flood Warnings in Pennsylvania, 2021Flash Flood Warnings in New Jersey, 2021Flash Flood Warnings in Delaware, 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.