Alert archive / New Jersey / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 12, NWS Philadelphia/Mount Holly

April 5, 20114 counties in Pennsylvania; 6 counties in New Jersey; New Castle County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Apr 5, 2011, 10:16 AM EDT for 4 counties in Pennsylvania; 6 counties in New Jersey; New Castle County, Delaware. 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 5, 2011, 10:16 AM EDT (14:16 UTC)
Expired
Apr 5, 2011, 11:00 AM EDT
In force
44 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

Counties New Castle County, DE, Atlantic County, NJ, Burlington County, NJ, Camden County, NJ, Cumberland County, NJ, Gloucester County, NJ, Salem County, NJ, Bucks County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 87 km from the middle of the area, began a volume at 14:16 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 5, 10:27 AM EDTTSTM WND GST 61Folcroft, PAWIND GUST OF 61 MPH

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, 2.3 hours before the alert went out and 67 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 2011-04-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2011-04-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 106 square meters per square second.1939587897117Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1186 m above ground
0-6 km bulk shear
79 kt
0-1 km storm-relative helicity
106 m²/s²
0-3 km storm-relative helicity
133 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.

425 
WUUS51 KPHI 051416
SVRPHI
DEC003-NJC001-005-007-011-015-033-PAC017-045-091-101-051500-
/O.NEW.KPHI.SV.W.0012.110405T1416Z-110405T1500Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1016 AM EDT TUE APR 5 2011

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHEASTERN NEW CASTLE COUNTY IN NORTHERN DELAWARE...
  THIS INCLUDES THE CITY OF WILMINGTON...
  SOUTHEASTERN BUCKS COUNTY IN SOUTHEAST PENNSYLVANIA...
  EASTERN DELAWARE COUNTY IN SOUTHEAST PENNSYLVANIA...
  SOUTHEASTERN MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA...
  PHILADELPHIA COUNTY IN SOUTHEAST PENNSYLVANIA...
  THIS INCLUDES THE CITY OF PHILADELPHIA...
  NORTHWESTERN ATLANTIC COUNTY IN SOUTHERN NEW JERSEY...
  NORTHWESTERN BURLINGTON COUNTY IN SOUTHERN NEW JERSEY...
  CAMDEN COUNTY IN SOUTHERN NEW JERSEY...
  THIS INCLUDES THE CITY OF CAMDEN...
  NORTHERN CUMBERLAND COUNTY IN SOUTHERN NEW JERSEY...
  THIS INCLUDES THE CITY OF VINELAND...
  GLOUCESTER COUNTY IN SOUTHERN NEW JERSEY...
  SALEM COUNTY IN SOUTHERN NEW JERSEY...

* UNTIL 1100 AM EDT

* AT 1012 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING WINDS IN
  EXCESS OF 60 MPH.  THESE STORMS WERE LOCATED ALONG A LINE EXTENDING
  FROM CONSHOHOCKEN TO ARDEN TO DELAWARE CITY...OR ALONG A LINE
  EXTENDING FROM 12 MILES WEST OF PHILADELPHIA TO WILMINGTON TO 10
  MILES SOUTH OF WILMINGTON...AND MOVING EAST AT 35 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO BRYN
  MAWR...CHESTER...SWARTHMORE...DREXEL HILL...AMBLER...NARBERTH...
  BECKETT...CHESTNUT HILL...SALEM...MORRIS PARK...EAST LANSDOWNE...
  FOLCROFT...YEADON...ROXBOROUGH...PHILADELPHIA INTERNATIONAL
  AIRPORT...GIBBSTOWN...SWEDESBORO...GERMANTOWN...PAULSBORO...SOUTH
  PHILADELPHIA...JENKINTOWN...WILLOW GROVE...ABINGTON...WOODSTOWN...
  WEST DEPTFORD...CENTER CITY...ALLOWAY...ROCKLEDGE...NATIONAL
  PARK...KENSINGTON...BRYN ATHYN...MULLICA HILL...WOODBURY...
  DEPTFORD...WOODBURY HEIGHTS...WESTVILLE...GLOUCESTER CITY...
  WISSINOMING...TACONY...NORTHEAST PHILADELPHIA...HOLMESBURG...
  FEASTERVILLE...BELLMAWR...PALMYRA...PITMAN...ANDALUSIA...
  BENSALEM...GLASSBORO...SEABROOK FARMS...RIVERSIDE...MAGNOLIA...
  ELMER...TURNERSVILLE...CHERRY HILL...BEVERLY...OLIVET...CLAYTON...
  SPRINGDALE...GREENTREE...LINDENWOLD...WILLINGBORO...MOUNT LAUREL...
  VOORHEES...FRANKLINVILLE...BRISTOL...MARLTON...ROSENHAYN...
  BURLINGTON...TULLYTOWN...SICKLERVILLE...BERLIN...WILLIAMSTOWN...
  MALAGA...MONROE TOWNSHIP...FLORENCE...SOUTH VINELAND...MARLTON
  LAKES...LUMBERTON...JOBSTOWN...JACKSONVILLE...ATCO...VICTORY
  LAKES...NEWFIELD...MOUNT HOLLY...MEDFORD...CHESILHURST AND BUENA

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS SEVERE THUNDERSTORM MAY CONTAIN LITTLE OR NO LIGHTNING. DO NOT
WAIT FOR THUNDER BEFORE TAKING COVER. SEEK SHELTER IMMEDIATELY INSIDE
A STURDY STRUCTURE AND STAY AWAY FROM WINDOWS.

&&

LAT...LON 3968 7480 3941 7499 3953 7554 3958 7554
      3958 7556 3954 7556 3955 7563 3960 7560
      3960 7558 3963 7557 3968 7551 3969 7552
      3965 7557 4017 7530 4014 7465
TIME...MOT...LOC 1415Z 281DEG 30KT 4007 7532 3978 7543
          3958 7557

$$
DRAG
1 follow-up statement
802 
WWUS51 KPHI 051430
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1030 AM EDT TUE APR 5 2011

DEC003-PAC017-045-091-051438-
/O.CAN.KPHI.SV.W.0012.000000T0000Z-110405T1500Z/
DELAWARE PA-MONTGOMERY PA-BUCKS PA-NEW CASTLE DE-
1030 AM EDT TUE APR 5 2011

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN NEW CASTLE...
SOUTHEASTERN BUCKS...SOUTHEASTERN MONTGOMERY AND EASTERN DELAWARE
COUNTIES IS CANCELLED...

LAT...LON 3956 7548 3987 7522 4002 7517 4002 7511
      4009 7500 4003 7500 4003 7469 3968 7480
      3941 7499
TIME...MOT...LOC 1428Z 281DEG 30KT 4005 7518 3975 7529
          3956 7543

$$

NJC001-005-007-011-015-033-PAC101-051500-
/O.CON.KPHI.SV.W.0012.000000T0000Z-110405T1500Z/
SALEM NJ-CUMBERLAND NJ-CAMDEN NJ-GLOUCESTER NJ-PHILADELPHIA PA-
ATLANTIC NJ-BURLINGTON NJ-
1030 AM EDT TUE APR 5 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1100 AM EDT
FOR WEST CENTRAL BURLINGTON...NORTHWESTERN ATLANTIC...SOUTHEASTERN
PHILADELPHIA...GLOUCESTER...CAMDEN...NORTH CENTRAL CUMBERLAND AND
SALEM COUNTIES...

AT 1028 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE A LINE OF SHOWERS AND THUNDERSTORMS CAPABLE OF PRODUCING 
DAMAGING WINDS OF AROUND 60 MPH.  THESE STORMS WERE LOCATED ALONG A 
LINE EXTENDING FROM NORTHWEST PHILADELPHIA TO SWEDESBORO TO 
SALEM...MOVING EAST AT 35 MPH.

LAT...LON 3956 7548 3987 7522 4002 7517 4002 7511
      4009 7500 4003 7500 4003 7469 3968 7480
      3941 7499
TIME...MOT...LOC 1428Z 281DEG 30KT 4005 7518 3975 7529
          3956 7543

$$

MPD

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 5, 4:03 AM EDTSpecial Weather StatementPHIBerks57 min
Apr 5, 5:01 AM EDTSevere Thunderstorm WarningPHIChester, Delaware74 min
Apr 5, 5:23 AM EDTSevere Thunderstorm WarningPHIBerks, Bucks, Chester, Delaware, Lehigh, Montgomery and 1 more67 min
Apr 5, 5:58 AM EDTSpecial Weather StatementPHIMonroe, Northampton62 min
Apr 5, 6:05 AM EDTSpecial Weather StatementPHIPhiladelphia55 min
Apr 5, 6:30 AM EDTSpecial Weather StatementPHIPhiladelphia60 min
Apr 5, 8:55 AM EDTSpecial Weather StatementPHIBucks, Chester, Delaware, Lehigh, Montgomery, Northampton65 min
Apr 5, 9:37 AM EDTSpecial Weather StatementPHIBucks, Chester, Delaware, Montgomery, Philadelphia53 min
Apr 5, 6:42 AM EDTSpecial Weather StatementPHICape May, Cumberland63 min
Apr 5, 7:05 AM EDTSpecial Weather StatementPHIMorris55 min
Apr 5, 7:07 AM EDTSpecial Weather StatementPHIBurlington, Middlesex, Monmouth, Ocean53 min
Apr 5, 10:20 AM EDTSevere Thunderstorm WarningPHIAtlantic, Cape May, Cumberland40 min
Apr 5, 10:30 AM EDTSpecial Weather StatementPHIMercer, Middlesex, Monmouth, Morris, Somerset60 min
Apr 5, 10:35 AM EDTSpecial Marine WarningPHI55 min
Apr 5, 10:41 AM EDTSevere Thunderstorm WarningPHIAtlantic, Cumberland, Salem19 min
Apr 5, 10:58 AM EDTSpecial Weather StatementPHIAtlantic, Burlington, Camden, Cape May, Cumberland, Middlesex and 2 more92 min
Apr 5, 11:00 AM EDTSevere Thunderstorm WarningPHIBurlington, Monmouth, Ocean30 min
Apr 5, 11:09 AM EDTSpecial Marine WarningPHI96 min
Apr 5, 11:45 AM EDTSpecial Marine WarningPHI60 min
Apr 5, 2:57 PM EDTSmall Craft AdvisoryPHI27 hr
Apr 5, 5:28 AM EDTSevere Thunderstorm WarningPHIKent, New Castle, Sussex62 min
Apr 5, 3:05 PM EDTFrost AdvisoryPHIKent, Sussex13 hr

Nearby

Severe Thunderstorm Warnings in New Jersey, 2011Severe Thunderstorm Warnings in Pennsylvania, 2011Severe Thunderstorm Warnings in Delaware, 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.