Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 22, NWS Philadelphia/Mount Holly

April 27, 20114 counties in Pennsylvania; Burlington County, Camden County, Gloucester County, New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Apr 27, 2011, 2:31 PM EDT for 4 counties in Pennsylvania; Burlington County, Camden County, Gloucester County, New Jersey. It was in force for 44 min. 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
Apr 27, 2011, 2:31 PM EDT (18:31 UTC)
Expired
Apr 27, 2011, 3:15 PM EDT
In force
44 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

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

The radar

The Philadelphia radar (KDIX), 79 km from the middle of the area, began a volume at 18:33 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
Apr 27, 3:00 PM EDTTSTM WND DMGCamden, NJ*** 1 INJ *** WOMAN STRUCK BY TREE IN CAMDEN.

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, 6.5 hours before the alert went out and 77 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 2011-04-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 139 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°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 2011-04-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 77 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
139 J/kg
Mixed-layer CIN
-57 J/kg
Mixed-layer LCL
640 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
77 m²/s²
0-3 km storm-relative helicity
84 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.

980 
WUUS51 KPHI 271831
SVRPHI
NJC005-007-015-PAC017-045-091-101-271915-
/O.NEW.KPHI.SV.W.0022.110427T1831Z-110427T1915Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
231 PM EDT WED APR 27 2011

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EXTREME SOUTH CENTRAL BUCKS COUNTY IN SOUTHEAST PENNSYLVANIA...
  SOUTHEASTERN DELAWARE COUNTY IN SOUTHEAST PENNSYLVANIA...
  SOUTHEASTERN MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA...
  PHILADELPHIA COUNTY IN SOUTHEAST PENNSYLVANIA...
  THIS INCLUDES THE CITY OF PHILADELPHIA...
  WEST CENTRAL BURLINGTON COUNTY IN SOUTHERN NEW JERSEY...
  NORTHWESTERN CAMDEN COUNTY IN SOUTHERN NEW JERSEY...
  THIS INCLUDES THE CITY OF CAMDEN...
  NORTHWESTERN GLOUCESTER COUNTY IN SOUTHERN NEW JERSEY...

* UNTIL 315 PM EDT

* AT 229 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
  A SEVERE THUNDERSTORM CAPABLE OF PRODUCING DAMAGING WINDS UP TO 60 
  MPH.  THIS STORM WAS LOCATED NEAR CHESTER...OR 12 MILES NORTHEAST 
  OF WILMINGTON...AND MOVING NORTHEAST AT 35 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  GIBBSTOWN...PAULSBORO...SWARTHMORE AND NETHER PROVIDENCE TOWNSHIP
  AROUND 235 PM EDT...
  FOLCROFT...PHILADELPHIA INTERNATIONAL AIRPORT AND WEST DEPTFORD
  AROUND 240 PM EDT...
  YEADON...SOUTH PHILADELPHIA AND EAST LANSDOWNE AROUND 245 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 3969 7533 3972 7537 3977 7540 3978 7542
      3980 7542 3983 7548 3983 7549 4019 7510
      3996 7488
TIME...MOT...LOC 1830Z 220DEG 29KT 3983 7534

$$

HEAVENER/GIGI
2 follow-up statements
399 
WWUS51 KPHI 271851
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
251 PM EDT WED APR 27 2011

PAC045-271901-
/O.CAN.KPHI.SV.W.0022.000000T0000Z-110427T1915Z/
DELAWARE PA-
251 PM EDT WED APR 27 2011

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN DELAWARE COUNTY
IS CANCELLED...

LAT...LON 3979 7522 3985 7531 3985 7525 3990 7527
      3994 7525 3998 7528 4019 7510 3996 7488
TIME...MOT...LOC 1851Z 220DEG 29KT 3996 7520

$$

NJC005-007-015-PAC017-091-101-271915-
/O.CON.KPHI.SV.W.0022.000000T0000Z-110427T1915Z/
CAMDEN NJ-GLOUCESTER NJ-PHILADELPHIA PA-MONTGOMERY PA-BUCKS PA-
BURLINGTON NJ-
251 PM EDT WED APR 27 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 315 PM EDT
FOR WEST CENTRAL BURLINGTON...SOUTH CENTRAL BUCKS...SOUTHEASTERN
MONTGOMERY...PHILADELPHIA...NORTH CENTRAL GLOUCESTER AND NORTHWESTERN
CAMDEN COUNTIES...

AT 246 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING DAMAGING WINDS IN
UP TO 60 MPH.  THIS STORM WAS LOCATED NEAR COLWYN...OR 7 MILES
WEST OF CAMDEN...MOVING NORTHEAST AT 35 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  PHILADELPHIA...KENSINGTON...GERMANTOWN AND PENNSAUKEN BY 300 PM
  EDT...
  WISSINOMING...TACONY...WYNCOTE AND GLENSIDE BY 305 PM EDT...
  ROCKLEDGE AND NORTHEAST PHILADELPHIA BY 310 PM EDT...

LAT...LON 3979 7522 3985 7531 3985 7525 3990 7527
      3994 7525 3998 7528 4019 7510 3996 7488
TIME...MOT...LOC 1851Z 220DEG 29KT 3996 7520

$$

HEAVENER
577 
WWUS51 KPHI 271902
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
302 PM EDT WED APR 27 2011

NJC015-271911-
/O.CAN.KPHI.SV.W.0022.000000T0000Z-110427T1915Z/
GLOUCESTER NJ-
302 PM EDT WED APR 27 2011

...THE SEVERE THUNDERSTORM WARNING FOR NORTH CENTRAL GLOUCESTER
COUNTY IS CANCELLED...

LAT...LON 3985 7510 3988 7515 3988 7518 3985 7523
      3985 7524 3990 7526 3994 7525 3998 7528
      4019 7510 3996 7488
TIME...MOT...LOC 1901Z 220DEG 29KT 4002 7513

$$

NJC005-007-PAC017-091-101-271915-
/O.CON.KPHI.SV.W.0022.000000T0000Z-110427T1915Z/
CAMDEN NJ-PHILADELPHIA PA-MONTGOMERY PA-BUCKS PA-BURLINGTON NJ-
302 PM EDT WED APR 27 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 315 PM EDT
FOR WEST CENTRAL BURLINGTON...SOUTH CENTRAL BUCKS...SOUTHEASTERN
MONTGOMERY...PHILADELPHIA AND NORTHWESTERN CAMDEN COUNTIES...

AT 259 PM EDT...A SEVERE THUNDERSTORM WAS REPORTED CAPABLE OF
PRODUCING DAMAGING WINDS UP TO 60 MPH.  THIS STORM WAS LOCATED
NEAR PHILADELPHIA...MOVING NORTHEAST AT 35 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  7 MILES NORTHWEST OF CINNAMINSON BY 305 PM EDT...
  ROCKLEDGE...NORTHEAST PHILADELPHIA...JENKINTOWN AND HOLMESBURG BY
  310 PM EDT...
  BRYN ATHYN...6 MILES SOUTHEAST OF HATBORO AND 6 MILES NORTHWEST OF
  RIVERSIDE BY 315 PM EDT...

LAT...LON 3985 7510 3988 7515 3988 7518 3985 7523
      3985 7524 3990 7526 3994 7525 3998 7528
      4019 7510 3996 7488
TIME...MOT...LOC 1901Z 220DEG 29KT 4002 7513

$$

HEAVENER

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 26, 10:01 PM EDTSpecial Weather StatementPHICarbon59 min
Apr 26, 10:55 PM EDTSpecial Weather StatementPHIMonroe50 min
Apr 26, 11:10 PM EDTSpecial Weather StatementPHIBerks65 min
Apr 26, 11:34 PM EDTSevere Thunderstorm WarningPHIBerks, Carbon56 min
Apr 26, 11:41 PM EDTSpecial Weather StatementPHIMonroe64 min
Apr 26, 11:45 PM EDTSpecial Weather StatementPHILehigh, Northampton60 min
Apr 27, 12:08 AM EDTSpecial Weather StatementPHIMonroe, Northampton67 min
Apr 27, 12:34 AM EDTSevere Thunderstorm WarningPHIMonroe, Northampton56 min
Apr 27, 1:19 AM EDTSpecial Weather StatementPHIBucks56 min
Apr 27, 1:48 PM EDTSpecial Weather StatementPHIDelaware, Montgomery, Philadelphia87 min
Apr 27, 3:26 PM EDTFlash Flood WatchPHICarbon, Lehigh, Monroe, Northampton24 hr
Apr 27, 4:43 PM EDTSevere Thunderstorm WarningPHIDelaware36 min
Apr 26, 9:25 PM EDTMarine Dense Fog AdvisoryPHI6 hr
Apr 27, 12:43 AM EDTSpecial Weather StatementPHIHunterdon, Somerset62 min
Apr 27, 3:25 AM EDTSpecial Weather StatementPHIHunterdon, Morris65 min
Apr 27, 3:30 AM EDTFlood WatchPHIMercer, Middlesex, Morris, Somerset12 hr
Apr 27, 3:29 PM EDTSpecial Weather StatementPHIMorris, Somerset61 min
Apr 27, 3:39 PM EDTSevere Thunderstorm WarningPHIMorris, Somerset, Sussex66 min
Apr 27, 4:16 PM EDTSpecial Weather StatementPHISalem59 min
Apr 27, 4:43 PM EDTSpecial Weather StatementPHICamden, Cumberland, Gloucester, Salem62 min
Apr 27, 4:50 PM EDTSpecial Marine WarningPHI12 min
Apr 27, 5:22 PM EDTSpecial Weather StatementPHIBurlington, Camden, Gloucester83 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.