Alert archive / New Jersey / Severe Thunderstorm Warnings in 2013

Severe Thunderstorm Warning 74, NWS Philadelphia/Mount Holly

July 20, 2013Burlington County, Camden County, Gloucester County, New Jersey; Delaware County, Philadelphia County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 20, 2013, 8:49 PM EDT for Burlington County, Camden County, Gloucester County, New Jersey; Delaware County, Philadelphia County, Pennsylvania. It was in force for 56 min. 6 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 20, 2013, 8:49 PM EDT (00:49 UTC)
Expired
Jul 20, 2013, 9:45 PM EDT
In force
56 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

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

The radar

The Philadelphia radar (KDIX), 47 km from the middle of the area, began a volume at 00:51 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 20, 8:56 PM EDTTSTM WND GST 53Philadelphia Intl Airpo, PA
Jul 20, 9:02 PM EDTTSTM WND GST 66Philadelphia Intl Airpo, PA
Jul 20, 9:05 PM EDTTSTM WND DMGNational Park, NJTREES DOWN
Jul 20, 9:05 PM EDTTSTM WND DMGWest Deptford Twp, NJWIRES DOWN ON HESSIAN AVE
Jul 20, 9:05 PM EDTTSTM WND DMGWoodbury, NJTREE AND WIRES DOWN
Jul 20, 9:05 PM EDTTSTM WND GST 52Woodbury, NJ

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, 0.8 hours before the alert went out and 208 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 2013-07-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1732 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 2013-07-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 21 square meters per square second.193958Sfc1 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
1732 J/kg
Mixed-layer CIN
-38 J/kg
Mixed-layer LCL
1353 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
21 m²/s²
0-3 km storm-relative helicity
34 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.9

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

731 
WUUS51 KPHI 210049
SVRPHI
NJC005-007-015-PAC045-101-210145-
/O.NEW.KPHI.SV.W.0074.130721T0049Z-130721T0145Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
849 PM EDT SAT JUL 20 2013

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHERN CAMDEN COUNTY IN SOUTHERN NEW JERSEY...
  SOUTHWESTERN PHILADELPHIA COUNTY IN SOUTHEAST PENNSYLVANIA...
  EAST CENTRAL DELAWARE COUNTY IN SOUTHEAST PENNSYLVANIA...
  NORTH CENTRAL GLOUCESTER COUNTY IN SOUTHERN NEW JERSEY...
  WEST CENTRAL BURLINGTON COUNTY IN SOUTHERN NEW JERSEY...

* UNTIL 945 PM EDT

* AT 847 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM. THE STORM WAS NEAR EDDYSTONE...MOVING EAST AT
  30 MPH. THIS STORM IS CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS
  OF 60 MPH. 

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  PHILADELPHIA INTERNATIONAL AIRPORT AND PAULSBORO AROUND 855 PM
  EDT...
  WEST DEPTFORD AND SOUTH PHILADELPHIA AROUND 900 PM EDT...
  NATIONAL PARK AND WOODBURY AROUND 905 PM EDT...
  WESTVILLE AND GLOUCESTER CITY AROUND 910 PM EDT...
  BELLMAWR AROUND 915 PM EDT...
  MAGNOLIA AROUND 920 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

VERY HEAVY RAIN WILL ALSO OCCUR WITH THIS SEVERE THUNDERSTORM...WHICH
COULD FLOOD LOW LYING AREAS QUICKLY AND COVER ROADS WITH WATER. DO
NOT DRIVE INTO AREAS WHERE WATER COVERS THE ROAD.

FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THIS SEVERE
THUNDERSTORM. WHEN THUNDER ROARS...MOVE INDOORS! REMEMBER...IF YOU
CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE STRUCK BY LIGHTNING.

&&

LAT...LON 3997 7471 3977 7469 3980 7534 3992 7535
TIME...MOT...LOC 0049Z 270DEG 24KT 3986 7530

$$

FORECASTER: HEAVENER
2 follow-up statements
795 
WWUS51 KPHI 210108
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
908 PM EDT SAT JUL 20 2013

PAC045-210116-
/O.CAN.KPHI.SV.W.0074.000000T0000Z-130721T0145Z/
DELAWARE PA-
908 PM EDT SAT JUL 20 2013

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL DELAWARE COUNTY
IS CANCELLED...

THE STORM THAT PROMPTED THE SEVERE THUNDERSTORM WARNING HAS MOVED OUT
OF THE AREA...THEREFORE THE SEVERE THUNDERSTORM WARNING HAS BEEN
CANCELLED.

LAT...LON 3980 7520 3990 7522 3997 7471 3977 7469
TIME...MOT...LOC 0106Z 270DEG 24KT 3986 7515

$$

NJC005-007-015-PAC101-210145-
/O.CON.KPHI.SV.W.0074.000000T0000Z-130721T0145Z/
CAMDEN NJ-PHILADELPHIA PA-GLOUCESTER NJ-BURLINGTON NJ-
908 PM EDT SAT JUL 20 2013

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 945 PM EDT
FOR CENTRAL BURLINGTON...NORTH CENTRAL GLOUCESTER...SOUTH CENTRAL
PHILADELPHIA AND NORTHERN CAMDEN COUNTIES...

AT 903 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING DAMAGING WINDS IN
EXCESS OF 60 MPH. THIS STORM WAS LOCATED NEAR NATIONAL PARK...OR NEAR
GLOUCESTER CITY...MOVING EAST AT 30 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
BELLMAWR AND RUNNEMEDE AROUND 915 PM EDT...
MAGNOLIA AND LAWNSIDE AROUND 920 PM EDT...
SPRINGDALE AND GIBBSBORO AROUND 925 PM EDT...
VOORHEES AND GREENTREE AROUND 930 PM EDT...
EVESHAM AND MARLTON LAKES AROUND 935 PM EDT...
MEDFORD LAKES AND MEDFORD AROUND 945 PM EDT...

WIND GUSTS TO AT LEAST 53 MPH WERE REPORTED AT PHILADELPHIA 
INTERNATIONAL AIRPORT AT 856 PM.  

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF YOU ARE IN THE PATH OF THIS STORM...PREPARE FOR DAMAGING 
WINDS...DEADLY CLOUD TO GROUND LIGHTNING AND POOR DRAINAGE FLOODING 
FROM BRIEF TORRENTIAL RAINS. PEOPLE OUTSIDE SHOULD MOVE TO A 
SHELTER...PREFERABLY INSIDE A STRONG BUILDING...AWAY FROM WINDOWS OR 
EVEN BELOW GROUND LEVEL.


&&

LAT...LON 3980 7520 3990 7522 3997 7471 3977 7469
TIME...MOT...LOC 0106Z 270DEG 24KT 3986 7515

$$

FORECASTER:  DRAG
054 
WWUS51 KPHI 210118
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
918 PM EDT SAT JUL 20 2013

NJC015-PAC101-210126-
/O.CAN.KPHI.SV.W.0074.000000T0000Z-130721T0145Z/
PHILADELPHIA PA-GLOUCESTER NJ-
918 PM EDT SAT JUL 20 2013

...THE SEVERE THUNDERSTORM WARNING FOR NORTH CENTRAL GLOUCESTER AND
SOUTH CENTRAL PHILADELPHIA COUNTIES IS CANCELLED...

THE STORM THAT PROMPTED THE SEVERE THUNDERSTORM WARNING HAS MOVED OUT
OF THE AREA...THEREFORE THE SEVERE THUNDERSTORM WARNING HAS BEEN
CANCELLED.

LAT...LON 3979 7508 3982 7509 3984 7508 3986 7511
      3986 7512 3991 7510 3997 7471 3977 7469
TIME...MOT...LOC 0116Z 269DEG 24KT 3991 7504 3985 7505
          3980 7508

$$

NJC005-007-210145-
/O.CON.KPHI.SV.W.0074.000000T0000Z-130721T0145Z/
CAMDEN NJ-BURLINGTON NJ-
918 PM EDT SAT JUL 20 2013

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 945 PM EDT
FOR CENTRAL BURLINGTON AND NORTHERN CAMDEN COUNTIES...

AT 912 PM EDT...A LINE OF SEVERE THUNDERSTORMS WAS REPORTED CAPABLE
OF PRODUCING DESTRUCTIVE WINDS IN EXCESS OF 60 MPH. THESE STORMS WERE
LOCATED ALONG A LINE EXTENDING FROM COLLINGSWOOD TO RUNNEMEDE TO
BLACKWOOD...MOVING EAST AT 25 MPH.

SEVERE THUNDERSTORMS WILL BE NEAR...
PINE HILL AND LINDENWOLD AROUND 925 PM EDT...
MOUNT LAUREL AND PINE VALLEY AROUND 930 PM EDT...
BERLIN AND MARLTON LAKES AROUND 935 PM EDT...
MEDFORD AND MEDFORD LAKES AROUND 940 PM EDT...
TABERNACLE AND SHAMONG AROUND 945 PM EDT...

WINDS GUSTS TO 66 MPH OCCURRED AT PHILADELPHIA INTERNATIONAL AIRPORT 
AT 902 PM.  

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS STORM HAS A HISTORY OF PRODUCING WINDS IN EXCESS OF 60 MPH.

IF YOU ARE IN THE PATH OF THIS STORM...PREPARE FOR DAMAGING 
WINDS...DEADLY CLOUD TO GROUND LIGHTNING...BRIEF TORRENTIAL RAINS 
AND ASSOCIATED POOR DRAINAGE FLOODING. PEOPLE OUTSIDE SHOULD MOVE 
TO A SHELTER...PREFERABLY INSIDE A STRONG BUILDING...AWAY FROM 
WINDOWS OR EVEN BELOW GROUND LEVEL.


&&

LAT...LON 3979 7508 3982 7509 3984 7508 3986 7511
      3986 7512 3991 7510 3997 7471 3977 7469
TIME...MOT...LOC 0116Z 269DEG 24KT 3991 7504 3985 7505
          3980 7508

$$

FORECASTER:  DRAG

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 20, 8:33 PM EDTSpecial Weather StatementPHICamden57 min
Jul 20, 8:39 PM EDTSpecial Weather StatementPHICamden66 min
Jul 20, 9:13 PM EDTSpecial Weather StatementPHIOcean32 min
Jul 20, 9:38 PM EDTSevere Thunderstorm WarningPHIBurlington67 min
Jul 20, 9:51 PM EDTSevere Thunderstorm WarningPHIAtlantic, Burlington, Ocean54 min
Jul 20, 9:59 PM EDTSevere Thunderstorm WarningPHIBurlington, Camden61 min
Jul 20, 10:07 PM EDTSpecial Marine WarningPHI83 min
Jul 20, 10:46 PM EDTSpecial Weather StatementPHIBurlington59 min
Jul 20, 10:52 PM EDTSpecial Weather StatementPHIAtlantic53 min
Jul 20, 11:10 PM EDTSpecial Marine WarningPHI95 min
Jul 21, 3:10 PM EDTSpecial Weather StatementPHIOcean65 min
Jul 21, 3:17 PM EDTCoastal Flood AdvisoryPHIMiddlesex, Monmouth, Ocean6 hr
Jul 21, 3:44 PM EDTSpecial Weather StatementPHICamden, Gloucester, Salem2 hr
Jul 21, 4:16 PM EDTSpecial Weather StatementPHIBurlington89 min
Jul 21, 4:20 PM EDTAreal Flood AdvisoryPHIBurlington3 hr
Jul 21, 4:44 PM EDTSpecial Weather StatementPHIBurlington61 min
Jul 21, 5:03 PM EDTAreal Flood AdvisoryPHIBurlington3 hr
Jul 21, 5:18 PM EDTSevere Thunderstorm WarningPHIBurlington57 min
Jul 21, 5:28 PM EDTAreal Flood AdvisoryPHIBurlington3 hr
Jul 21, 5:52 PM EDTSpecial Weather StatementPHIOcean53 min
Jul 21, 6:20 PM EDTSpecial Weather StatementPHIAtlantic55 min
Jul 21, 6:33 PM EDTAreal Flood AdvisoryPHIBurlington, Ocean3 hr
Jul 21, 7:02 PM EDTSpecial Weather StatementPHIAtlantic88 min
Jul 21, 7:04 PM EDTSpecial Marine WarningPHI56 min
Jul 21, 7:25 PM EDTAreal Flood AdvisoryPHIAtlantic, Burlington3 hr

Nearby

Severe Thunderstorm Warnings in New Jersey, 2013Severe Thunderstorm Warnings in Pennsylvania, 2013Every severe thunderstorm warning in 2013

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.