Alert archive / Pennsylvania / Flash Flood Warnings in 2018

Flash Flood Warning 22, NWS Philadelphia/Mount Holly

July 3, 2018Delaware County, Montgomery County, Philadelphia County, Pennsylvania; Camden County, Gloucester County, New Jersey

NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 3, 2018, 5:45 PM EDT for Delaware County, Montgomery County, Philadelphia County, Pennsylvania; Camden County, Gloucester County, New Jersey. It was in force for 4 hr. 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 3, 2018, 5:45 PM EDT (21:45 UTC)
Expired
Jul 3, 2018, 9:45 PM EDT
In force
4 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

Counties Camden County, NJ, Gloucester County, NJ, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA

What was reported inside it

TimeReportWhereRemark
Jul 3, 6:30 PM EDTFLASH FLOODWestville, NJFLASH FLOODING REPORTED ON SEVERAL STREETS IN TOWN

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, 9.8 hours before the alert went out and 221 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 2018-07-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 574 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 2018-07-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 14 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
574 J/kg
Mixed-layer CIN
-189 J/kg
Mixed-layer LCL
1257 m above ground
0-6 km bulk shear
7 kt
0-1 km storm-relative helicity
14 m²/s²
0-3 km storm-relative helicity
55 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

955 
WGUS51 KPHI 032145
FFWPHI
NJC007-015-PAC045-091-101-040145-
/O.NEW.KPHI.FF.W.0022.180703T2145Z-180704T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
545 PM EDT TUE JUL 3 2018

The National Weather Service in Mount Holly NJ has issued a

* Flash Flood Warning for...
  Northwestern Camden County in southern New Jersey...
  North central Gloucester County in southern New Jersey...
  Southeastern Montgomery County in southeastern Pennsylvania...
  Southwestern Philadelphia County in southeastern Pennsylvania...
  Northeastern Delaware County in southeastern Pennsylvania...

* Until 945 PM EDT.

* At 544 PM EDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Up to two inches of rain have
  already fallen. Flash flooding is expected to begin shortly in the
  areas of heaviest rain.

* Some locations that could experience flooding include...
  Philadelphia, Camden, Gloucester City, Deptford, Voorhees,
  Lindenwold, Bellmawr, Yeadon, Woodbury, Folcroft, Magnolia,
  Westville, Narberth, Woodbury Heights, National Park, East
  Lansdowne, Brooklawn, Audubon Park, Darby Township and Morris Park.

Additional rainfall amounts of up to two inches are possible in the 
warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4007 7525 3984 7493 3976 7507 3997 7538

$$

SFJ
2 follow-up statements
025 
WGUS71 KPHI 040001
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
801 PM EDT TUE JUL 3 2018

NJC007-015-PAC045-091-101-040145-
/O.CON.KPHI.FF.W.0022.000000T0000Z-180704T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Camden NJ-Gloucester NJ-Montgomery PA-Philadelphia PA-Delaware PA-
801 PM EDT TUE JUL 3 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 945 PM EDT FOR
NORTHWESTERN CAMDEN...NORTH CENTRAL GLOUCESTER...SOUTHEASTERN
MONTGOMERY...SOUTHWESTERN PHILADELPHIA AND NORTHEASTERN DELAWARE
COUNTIES...

At 759 PM EDT, Doppler radar indicated thunderstorms producing heavy
rain across the warned area. Up to three inches of rain have already 
fallen. Flash flooding may already be occuring. Though the heaviest 
rain has left the warning area...it will take time for the runoff to 
recede.

Some locations that could experience flooding include...
Philadelphia, Camden, Gloucester City, Deptford, Voorhees,
Lindenwold, Bellmawr, Yeadon, Woodbury, Folcroft, Magnolia,
Westville, Narberth, Woodbury Heights, National Park, East Lansdowne,
Brooklawn, Audubon Park, Darby Township and Morris Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4007 7525 3984 7493 3976 7507 3997 7538

$$

SFJ
237 
WGUS71 KPHI 040024
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
824 PM EDT TUE JUL 3 2018

NJC007-015-040032-
/O.CAN.KPHI.FF.W.0022.000000T0000Z-180704T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Camden NJ-Gloucester NJ-
824 PM EDT TUE JUL 3 2018

...THE FLASH FLOOD WARNING FOR NORTHWESTERN CAMDEN AND NORTH CENTRAL
GLOUCESTER COUNTIES IS CANCELLED...

Flooding is no longer expected to pose a threat. Please continue to
heed any remaining road closures.

LAT...LON 3997 7538 4007 7525 3995 7514 3990 7514
      3986 7521 3987 7523

$$

PAC045-091-101-040145-
/O.CON.KPHI.FF.W.0022.000000T0000Z-180704T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Montgomery PA-Philadelphia PA-Delaware PA-
824 PM EDT TUE JUL 3 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 945 PM EDT FOR
SOUTHEASTERN MONTGOMERY...SOUTHWESTERN PHILADELPHIA AND NORTHEASTERN
DELAWARE COUNTIES...

At 822 PM EDT, Doppler radar indicated mainly light rain showers 
across southwestern Philadelphia County and adjacent areas of 
Montgomery and Delaware Counties. Since some small streams are 
running high, the Flash Flood Warning for the area remains in effect 
until this water recedes.

Some locations that could experience flooding include...
Philadelphia, Yeadon, Folcroft, Narberth, National Park, East
Lansdowne, Darby Township, Broomall, Morris Park, Roxborough, South
Philadelphia, Drexel Hill, Bryn Mawr, Darby, Lansdowne, Collingdale,
Clifton Heights, Sharon Hill, Aldan and Colwyn.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3997 7538 4007 7525 3995 7514 3990 7514
      3986 7521 3987 7523

$$

jjm

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 3, 2:15 PM EDTSpecial Weather StatementPHIDelaware30 min
Jul 3, 3:00 PM EDTSpecial Weather StatementPHIPhiladelphia60 min
Jul 3, 3:11 PM EDTFlash Flood WarningPHIMontgomery, Philadelphia50 min
Jul 3, 4:06 PM EDTSpecial Weather StatementPHIMontgomery54 min
Jul 3, 4:30 PM EDTSpecial Weather StatementPHIBucks60 min
Jul 3, 5:24 PM EDTAreal Flood AdvisoryPHIDelaware, Montgomery, Philadelphia4 hr
Jul 3, 5:29 PM EDTAreal Flood AdvisoryPHIBucks, Montgomery, Philadelphia4 hr
Jul 3, 5:30 PM EDTSpecial Weather StatementPHIPhiladelphia30 min
Jul 3, 6:03 PM EDTSpecial Weather StatementPHIMonroe57 min
Jul 3, 6:15 PM EDTSpecial Weather StatementPHIChester60 min
Jul 3, 6:18 PM EDTSevere Thunderstorm WarningPHIDelaware, Philadelphia42 min
Jul 3, 6:21 PM EDTSpecial Weather StatementPHIDelaware24 min
Jul 3, 6:25 PM EDTSevere Thunderstorm WarningPHIBucks, Philadelphia50 min
Jul 3, 6:37 PM EDTFlash Flood WarningPHIBucks, Philadelphia3 hr
Jul 3, 6:40 PM EDTAreal Flood AdvisoryPHIChester, Delaware4 hr
Jul 3, 6:50 PM EDTSpecial Weather StatementPHIDelaware55 min
Jul 3, 6:54 PM EDTSevere Thunderstorm WarningPHIChester, Delaware51 min
Jul 3, 6:58 PM EDTFlash Flood WarningPHIChester, Delaware4 hr
Jul 3, 7:03 PM EDTSpecial Weather StatementPHINorthampton57 min
Jul 3, 7:06 PM EDTFlash Flood WarningPHIBucks, Chester, Delaware, Montgomery, Philadelphia2 hr
Jul 3, 7:22 PM EDTSevere Thunderstorm WarningPHIChester, Delaware, Montgomery, Philadelphia21 min
Jul 3, 7:35 PM EDTSpecial Weather StatementPHIChester25 min
Jul 3, 7:39 PM EDTSevere Thunderstorm WarningPHIChester51 min
Jul 3, 7:54 PM EDTFlash Flood WarningPHIChester4 hr
Jul 3, 2:33 PM EDTSpecial Weather StatementPHIUnion27 min
Jul 3, 2:57 PM EDTSpecial Weather StatementPHIMorris63 min
Jul 3, 3:19 PM EDTFlash Flood WarningPHIMorris3 hr
Jul 3, 3:28 PM EDTSpecial Weather StatementPHISalem62 min
Jul 3, 3:30 PM EDTSpecial Weather StatementPHIBurlington60 min
Jul 3, 3:43 PM EDTFlash Flood WarningPHIMorris2 hr
Jul 3, 4:49 PM EDTSpecial Weather StatementPHISomerset56 min
Jul 3, 4:52 PM EDTSpecial Weather StatementPHIMercer53 min
Jul 3, 4:57 PM EDTFlash Flood WarningPHIHunterdon, Somerset114 min
Jul 3, 5:47 PM EDTFlash Flood WarningPHIHunterdon, Mercer, Middlesex, Somerset2 hr
Jul 3, 5:57 PM EDTSpecial Weather StatementPHIGloucester33 min
Jul 3, 6:11 PM EDTSevere Thunderstorm WarningPHICamden, Gloucester49 min
Jul 3, 6:46 PM EDTSevere Thunderstorm WarningPHIBurlington, Camden, Gloucester44 min
Jul 3, 6:58 PM EDTFlash Flood WarningPHIBurlington, Camden, Gloucester49 min

Nearby

Flash Flood Warnings in Pennsylvania, 2018Flash Flood Warnings in New Jersey, 2018Every flash flood warning in 2018

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.