Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 94, NWS Philadelphia/Mount Holly

June 9, 20118 counties in Pennsylvania; 4 counties in New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jun 9, 2011, 6:44 PM EDT for 8 counties in Pennsylvania; 4 counties in New Jersey. It was in force for 61 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
Jun 9, 2011, 6:44 PM EDT (22:44 UTC)
Expired
Jun 9, 2011, 7:45 PM EDT
In force
61 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

Counties Hunterdon County, NJ, Morris County, NJ, Somerset County, NJ, Warren County, NJ, Berks County, PA, Bucks County, PA, Carbon County, PA, Chester County, PA, Lehigh County, PA, Monroe County, PA, Montgomery County, PA, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 120 km from the middle of the area, began a volume at 22:45 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
Jun 9, 6:57 PM EDTHAIL 0.25North Catasauqua, PA
Jun 9, 6:59 PM EDTTSTM WND GST 52Hanover Twp, PALEHIGH VALLEY INTERNATIONAL AIRPORT
Jun 9, 7:30 PM EDTTSTM WND DMGBound Brook, NJLARGE BRANCES DOWN
Jun 9, 7:30 PM EDTHAIL 1Telford, PA
Jun 9, 7:35 PM EDTHAIL 0.75Perkasie, PA
Jun 9, 7:38 PM EDTHAIL 0.75New Britain, PA

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

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Jun 9, 2:34 PM EDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 10.7 hours before the alert went out and 141 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 2011-06-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 734 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 2011-06-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -20 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
734 J/kg
Mixed-layer CIN
-235 J/kg
Mixed-layer LCL
1935 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
-20 m²/s²
0-3 km storm-relative helicity
28 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.

806 
WUUS51 KPHI 092244
SVRPHI
NJC019-027-035-041-PAC011-017-025-029-077-089-091-095-092345-
/O.NEW.KPHI.SV.W.0094.110609T2244Z-110609T2345Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
644 PM EDT THU JUN 9 2011

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  BERKS COUNTY IN EASTERN PENNSYLVANIA...
  LEHIGH COUNTY IN EASTERN PENNSYLVANIA...
  THIS INCLUDES THE CITY OF ALLENTOWN...
  NORTHAMPTON COUNTY IN EASTERN PENNSYLVANIA...
  THIS INCLUDES THE CITY OF EASTON...
  SOUTHERN CARBON COUNTY IN NORTHEAST PENNSYLVANIA...
  THIS INCLUDES THE CITY OF LEHIGHTON...
  SOUTHERN MONROE COUNTY IN NORTHEAST PENNSYLVANIA...
  SOUTHERN MORRIS COUNTY IN NORTHERN NEW JERSEY...
  THIS INCLUDES THE CITY OF MORRISTOWN...
  SOMERSET COUNTY IN NORTHERN NEW JERSEY...
  THIS INCLUDES THE CITY OF SOMERVILLE...
  HUNTERDON COUNTY IN NORTHWEST NEW JERSEY...
  WARREN COUNTY IN NORTHWEST NEW JERSEY...
  BUCKS COUNTY IN SOUTHEAST PENNSYLVANIA...
  EXTREME NORTHEASTERN CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA...
  CENTRAL MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA...

* UNTIL 745 PM EDT

* AT 641 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING QUARTER SIZE
  HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THESE STORMS WERE
  LOCATED ALONG A LINE EXTENDING FROM MORRISTOWN TO WANAMAKERS...OR
  ALONG A LINE EXTENDING FROM MORRISTOWN TO 10 MILES SOUTHWEST OF
  LEHIGHTON...AND MOVING SOUTHEAST AT 30 TO 35 MPH.

* SEVERE THUNDERSTORMS WILL BE NEAR...
  KUTZTOWN...FLEETWOOD...COFFEETOWN AND CLAUSSVILLE AROUND 650 PM
  EDT...
  TOPTON...LYONS...MILLINGTON AND BASKING RIDGE AROUND 655 PM EDT...
  RIEGELSVILLE AND HELLERTOWN AROUND 700 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THESE ARE DANGEROUS STORMS. IF YOU ARE IN THE 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.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1000 PM EDT 
THURSDAY EVENING FOR NORTHERN DELAWARE AND NORTHEAST MARYLAND AND NEW
JERSEY AND EASTERN PENNSYLVANIA.

&&

LAT...LON 4047 7457 4041 7485 4007 7543 4043 7554
      4028 7583 4052 7621 4059 7607 4059 7603
      4065 7600 4074 7578 4080 7587 4092 7599
      4093 7597 4095 7593 4098 7487 4088 7478
      4091 7441
TIME...MOT...LOC 2243Z 300DEG 47KT 4078 7447 4068 7578

$$
2 follow-up statements
604 
WWUS51 KPHI 092307
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
707 PM EDT THU JUN 9 2011

NJC019-027-035-041-PAC011-017-025-029-077-089-091-095-092345-
/O.CON.KPHI.SV.W.0094.000000T0000Z-110609T2345Z/
WARREN NJ-MORRIS NJ-HUNTERDON NJ-SOMERSET NJ-CHESTER PA-MONTGOMERY 
PA-BERKS PA-LEHIGH PA-NORTHAMPTON PA-CARBON PA-BUCKS PA-MONROE 
707 PM EDT THU JUN 9 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 745 PM EDT
FOR EXTREME SOUTH CENTRAL MONROE...NORTHERN BUCKS...EXTREME
SOUTHEASTERN CARBON...NORTHAMPTON...LEHIGH...EASTERN BERKS...CENTRAL
MONTGOMERY...EXTREME NORTHEASTERN CHESTER...SOMERSET...HUNTERDON...
SOUTHERN MORRIS AND SOUTHERN WARREN COUNTIES...

AT 702 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING QUARTER
SIZE HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THESE STORMS
WERE LOCATED ALONG A LINE EXTENDING FROM 17 MILES EAST OF MILLINGTON
TO EMMAUS...OR ALONG A LINE EXTENDING FROM ELIZABETH TO ALLENTOWN...
MOVING SOUTHEAST AT 55 MPH.

SEVERE THUNDERSTORMS WILL BE NEAR...
  RED HILL...REVERE...PLEASANT VALLEY AND FERNDALE BY 710 PM EDT...
  TRUMBAUERSVILLE...SPRING MOUNT...SCHWENKSVILLE AND GREEN LANE BY
  715 PM EDT...
  TELFORD AND SOUDERTON BY 720 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

DOPPLER RADAR HAS INDICATED SOME WEAK ROTATION WITHIN THE STORM 
MOVING THROUGH FAR NORTHEASTERN HUNTERDON...NORTHWESTERN 
SOMERSET...AND SOUTHERN MORRIS COUNTIES. WHILE NOT IMMEDIATELY 
LIKELY...A TORNADO MAY STILL DEVELOP. IF A TORNADO IS SPOTTED...ACT 
QUICKLY AND MOVE TO A PLACE OF SAFETY IN A STURDY STRUCTURE...SUCH 
AS A BASEMENT OR SMALL INTERIOR ROOM.

IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...FREQUENT CLOUD TO
GROUND LIGHTNING IS OCCURRING WITH THIS STORM. MOVE INDOORS
IMMEDIATELY! LIGHTNING IS ONE OF NATURES NUMBER ONE KILLERS.
REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE
STRUCK BY LIGHTNING.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1000 PM EDT
THURSDAY EVENING FOR NORTHERN DELAWARE AND NORTHEAST MARYLAND AND NEW
JERSEY AND EASTERN PENNSYLVANIA.

&&

LAT...LON 4047 7457 4041 7485 4007 7543 4043 7554
      4028 7583 4035 7593 4046 7591 4061 7585
      4068 7567 4081 7554 4087 7531 4092 7493
      4088 7478 4091 7441
TIME...MOT...LOC 2305Z 300DEG 47KT 4063 7414 4054 7545

$$
389 
WWUS51 KPHI 092331
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
731 PM EDT THU JUN 9 2011

NJC041-PAC011-025-077-089-095-092339-
/O.CAN.KPHI.SV.W.0094.000000T0000Z-110609T2345Z/
WARREN NJ-BERKS PA-LEHIGH PA-NORTHAMPTON PA-CARBON PA-MONROE PA-
731 PM EDT THU JUN 9 2011

...THE SEVERE THUNDERSTORM WARNING FOR EXTREME SOUTH CENTRAL
MONROE...EXTREME SOUTHEASTERN CARBON...NORTHAMPTON...LEHIGH...EASTERN
BERKS AND SOUTHERN WARREN COUNTIES IS CANCELLED...

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1000 PM EDT
THURSDAY EVENING FOR NORTHERN DELAWARE AND NORTHEAST MARYLAND AND NEW
JERSEY AND EASTERN PENNSYLVANIA.

LAT...LON 4047 7457 4041 7485 4007 7543 4042 7552
      4042 7549 4061 7520 4059 7519 4070 7498
      4086 7479 4091 7441
TIME...MOT...LOC 2329Z 291DEG 40KT 4075 7459 4030 7537

$$

NJC019-027-035-PAC017-029-091-092345-
/O.CON.KPHI.SV.W.0094.000000T0000Z-110609T2345Z/
MORRIS NJ-HUNTERDON NJ-SOMERSET NJ-CHESTER PA-MONTGOMERY PA-BUCKS PA-
731 PM EDT THU JUN 9 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 745 PM EDT
FOR NORTHERN BUCKS...CENTRAL MONTGOMERY...EXTREME NORTHEASTERN
CHESTER...SOMERSET...HUNTERDON AND SOUTHERN MORRIS COUNTIES...

AT 727 PM EDT...A LINE OF SEVERE THUNDERSTORMS WAS REPORTED CAPABLE
OF PRODUCING QUARTER SIZE HAIL...AND DAMAGING WINDS IN EXCESS OF 60
MPH.  THESE STORMS WERE LOCATED ALONG A LINE EXTENDING FROM MENDHAM
TO HARLEYSVILLE...OR ALONG A LINE EXTENDING FROM 7 MILES WEST OF
MORRISTOWN TO 20 MILES SOUTH OF ALLENTOWN...MOVING EAST AT 45 MPH.

SEVERE THUNDERSTORMS WILL BE NEAR...
  MORRISTOWN...WEST NORRITON...EAST NORRITON AND LUMBERVILLE BY 735
  PM EDT...
  SERGEANTSVILLE...MILLINGTON...CLOVERHILL AND BRIDGEWATER BY 740 PM
  EDT...
  LAMBERTVILLE AND MANVILLE BY 745 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1000 PM EDT
THURSDAY EVENING FOR NORTHERN DELAWARE AND NORTHEAST MARYLAND AND NEW
JERSEY AND EASTERN PENNSYLVANIA.

&&

LAT...LON 4047 7457 4041 7485 4007 7543 4042 7552
      4042 7549 4061 7520 4059 7519 4070 7498
      4086 7479 4091 7441
TIME...MOT...LOC 2329Z 291DEG 40KT 4075 7459 4030 7537

$$

AMC

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 9, 4:41 PM EDTSevere Thunderstorm WarningPHICarbon, Monroe64 min
Jun 9, 5:43 PM EDTSevere Thunderstorm WarningPHIBerks, Carbon, Lehigh, Monroe, Northampton62 min
Jun 9, 6:24 PM EDTSevere Thunderstorm WarningPHIBerks, Chester, Montgomery66 min
Jun 9, 7:27 PM EDTSevere Thunderstorm WarningPHIBerks, Chester, Delaware, Montgomery48 min
Jun 9, 7:42 PM EDTSevere Thunderstorm WarningPHIBucks, Chester, Montgomery, Philadelphia33 min
Jun 9, 3:33 PM EDTSevere Thunderstorm WarningPHISussex16 min
Jun 9, 5:34 PM EDTSevere Thunderstorm WarningPHIMorris, Sussex41 min
Jun 9, 7:17 PM EDTSpecial Weather StatementPHIMonmouth43 min
Jun 9, 7:21 PM EDTSevere Thunderstorm WarningPHIMiddlesex, Monmouth39 min
Jun 9, 7:46 PM EDTSpecial Marine WarningPHI59 min
Jun 9, 7:57 PM EDTSevere Thunderstorm WarningPHIMercer, Middlesex, Monmouth18 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.