Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 154, NWS Philadelphia/Mount Holly

July 7, 20114 counties in Pennsylvania; Camden County, Gloucester County, New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 7, 2011, 5:12 PM EDT for 4 counties in Pennsylvania; Camden County, Gloucester County, New Jersey. It was in force for 63 min. 2 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 7, 2011, 5:12 PM EDT (21:12 UTC)
Expired
Jul 7, 2011, 6:15 PM EDT
In force
63 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

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

The radar

The Philadelphia radar (KDIX), 75 km from the middle of the area, began a volume at 21:12 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 7, 5:51 PM EDTTSTM WND GST 47Philadelphia Intl Airpo, PA
Jul 7, 6:00 PM EDTTSTM WND DMGPaulsboro, NJTREES AND WIRES REPORTED DOWN IN PAULSBORO.

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

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 9.2 hours before the alert went out and 87 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, Phillips Aaf/Abe, MD at 12:00Z on 2011-07-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 549 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, Phillips Aaf/Abe, MD at 12:00Z on 2011-07-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -7 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
549 J/kg
Mixed-layer CIN
-133 J/kg
Mixed-layer LCL
1227 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
-7 m²/s²
0-3 km storm-relative helicity
30 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

340 
WUUS51 KPHI 072112
SVRPHI
NJC007-015-PAC029-045-091-101-072215-
/O.NEW.KPHI.SV.W.0154.110707T2112Z-110707T2215Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
512 PM EDT THU JUL 7 2011

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EAST CENTRAL CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA...
  THIS INCLUDES THE CITY OF WEST CHESTER...
  DELAWARE COUNTY IN SOUTHEAST PENNSYLVANIA...
  SOUTH CENTRAL MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA...
  SOUTHWESTERN PHILADELPHIA COUNTY IN SOUTHEAST PENNSYLVANIA...
  NORTHWESTERN CAMDEN COUNTY IN SOUTHERN NEW JERSEY...
  THIS INCLUDES THE CITY OF CAMDEN...
  NORTHWESTERN GLOUCESTER COUNTY IN SOUTHERN NEW JERSEY...

* UNTIL 615 PM EDT

* AT 508 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR
  PAOLI...OR 7 MILES NORTHEAST OF WEST CHESTER...AND MOVING EAST AT
  15 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  GRADYVILLE AROUND 520 PM EDT...
  NEWTOWN SQUARE AND LIMA AROUND 525 PM EDT...
  RADNOR TOWNSHIP AROUND 530 PM EDT...
  TROUT LAKE AROUND 535 PM EDT...
  BROOMALL AND BRYN MAWR AROUND 540 PM EDT...
  SWARTHMORE AND NETHER PROVIDENCE TOWNSHIP AROUND 545 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...PREPARE
IMMEDIATELY FOR DAMAGING WINDS...DESTRUCTIVE HAIL...AND DEADLY CLOUD
TO GROUND LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING BUT AWAY FROM WINDOWS.

IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...HEAVY RAIN WILL OCCUR
WITH THESE STORMS AND CAUSE LOW-LYING AND POOR DRAINAGE FLOODING.

&&

LAT...LON 3994 7503 3976 7529 3996 7569 4015 7544
TIME...MOT...LOC 2112Z 291DEG 13KT 3999 7547

$$

NIERENBERG
1 follow-up statement
318 
WWUS51 KPHI 072156
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
556 PM EDT THU JUL 7 2011

PAC029-091-072205-
/O.CAN.KPHI.SV.W.0154.000000T0000Z-110707T2215Z/
CHESTER PA-MONTGOMERY PA-
556 PM EDT THU JUL 7 2011

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL MONTGOMERY AND
EAST CENTRAL CHESTER COUNTIES IS CANCELLED...

THE SEVERE THUNDERSTORM HAS MOVED EAST OF THE COUNTY.

LAT...LON 4000 7514 3994 7503 3976 7529 3982 7541
TIME...MOT...LOC 2155Z 242DEG 9KT 3986 7521

$$

NJC007-015-PAC045-101-072215-
/O.CON.KPHI.SV.W.0154.000000T0000Z-110707T2215Z/
CAMDEN NJ-GLOUCESTER NJ-DELAWARE PA-PHILADELPHIA PA-
556 PM EDT THU JUL 7 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 PM EDT
FOR SOUTHWESTERN PHILADELPHIA...SOUTHEASTERN DELAWARE...NORTHWESTERN
GLOUCESTER AND NORTHWESTERN CAMDEN COUNTIES...

AT 550 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 PAULSBORO...OR 8 MILES
SOUTHWEST OF CAMDEN...MOVING NORTHEAST AT 10 MPH.

THE PHILADELPHIA TERMINAL DOPPLER IS SHOWING A DOWNBURST ALONG THE 
GLOUCESTER COUNTY AND PHILADELPHIA COUNTY LINE 

THE SEVERE THUNDERSTORM WILL BE NEAR...
  NATIONAL PARK AND SOUTH PHILADELPHIA BY 605 PM EDT...
  GLOUCESTER CITY...WOODLYNNE...CAMDEN AND COLLINGSWOOD BY 615 PM
  EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...PREPARE
IMMEDIATELY FOR DAMAGING WINDS...DESTRUCTIVE HAIL...AND DEADLY CLOUD
TO GROUND LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING BUT AWAY FROM WINDOWS.

&&

LAT...LON 4000 7514 3994 7503 3976 7529 3982 7541
TIME...MOT...LOC 2155Z 242DEG 9KT 3986 7521

$$

TFG

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 7, 2:27 PM EDTSpecial Weather StatementPHIPhiladelphia93 min
Jul 7, 3:05 PM EDTSpecial Weather StatementPHILehigh55 min
Jul 7, 3:07 PM EDTSpecial Weather StatementPHIMonroe53 min
Jul 7, 3:26 PM EDTSevere Thunderstorm WarningPHIMonroe64 min
Jul 7, 4:35 PM EDTSevere Thunderstorm WarningPHIChester55 min
Jul 7, 1:27 PM EDTSpecial Weather StatementPHIBurlington93 min
Jul 7, 3:11 PM EDTSpecial Weather StatementPHIAtlantic64 min
Jul 7, 3:15 PM EDTSevere Thunderstorm WarningPHIAtlantic, Burlington, Ocean45 min
Jul 7, 3:16 PM EDTSpecial Marine WarningPHI89 min
Jul 7, 3:45 PM EDTSpecial Weather StatementPHIMercer, Middlesex90 min
Jul 7, 3:46 PM EDTSpecial Weather StatementPHIBurlington89 min
Jul 7, 3:58 PM EDTSevere Thunderstorm WarningPHIAtlantic, Burlington, Ocean34 min
Jul 7, 4:17 PM EDTSevere Thunderstorm WarningPHIBurlington, Ocean88 min
Jul 7, 4:19 PM EDTSevere Thunderstorm WarningPHIMorris, Sussex, Warren46 min
Jul 7, 4:48 PM EDTSevere Thunderstorm WarningPHIMonmouth, Ocean57 min
Jul 7, 5:44 PM EDTSpecial Weather StatementPHIBurlington, Monmouth, Ocean61 min
Jul 7, 6:10 PM EDTSevere Thunderstorm WarningPHIBurlington, Camden, Gloucester40 min
Jul 7, 6:46 PM EDTSevere Thunderstorm WarningPHIHunterdon, Middlesex, Somerset74 min
Jul 7, 6:48 PM EDTSpecial Weather StatementPHICamden57 min
Jul 7, 7:32 PM EDTSpecial Weather StatementPHIAtlantic, Burlington, Cape May, Cumberland, Salem88 min
Jul 7, 7:49 PM EDTSpecial Weather StatementPHIMercer86 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2011Severe Thunderstorm Warnings in New Jersey, 2011Every severe thunderstorm warning in 2011

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.