Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 79, NWS Philadelphia/Mount Holly

July 7, 2012Hunterdon County, Mercer County, Warren County, New Jersey; 8 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 7, 2012, 5:57 PM EDT for Hunterdon County, Mercer County, Warren County, New Jersey; 8 counties in Pennsylvania. It was in force for 63 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 7, 2012, 5:57 PM EDT (21:57 UTC)
Expired
Jul 7, 2012, 7:00 PM EDT
In force
63 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

Counties Hunterdon County, NJ, Mercer County, NJ, Warren County, NJ, Berks County, PA, Bucks County, PA, Chester County, PA, Delaware County, PA, Lehigh County, PA, Montgomery County, PA, Northampton County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 82 km from the middle of the area, began a volume at 22:00 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, 6:00 PM EDTTSTM WND GST 68Allentown, PA
Jul 7, 6:18 PM EDTTSTM WND GST 50Breinigsville, PA
Jul 7, 6:32 PM EDTTSTM WND DMGStockton, NJMETAL HAY WAGON AND CHICKEN COOP OVERTURNED ALONG SANFORD ROAD IN STOCKTON. ALSO WINDOW BLOWN OUT IN HOUSE AND LARGE TREE UPROOTED.
Jul 7, 6:35 PM EDTTSTM WND DMGFlemington, NJTREES DOWN
Jul 7, 6:45 PM EDTTSTM WND GST 55Trenton Airport, NJ
Jul 7, 6:45 PM EDTTSTM WND GST 60Langhorne, 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
Jul 7, 11:41 AM EDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 10.0 hours before the alert went out and 213 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 12:00Z on 2012-07-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 335 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, Brookhaven, NY at 12:00Z on 2012-07-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 104 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
335 J/kg
Mixed-layer CIN
-291 J/kg
Mixed-layer LCL
1325 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
104 m²/s²
0-3 km storm-relative helicity
164 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4

Open this sounding in Storm Lab

The text

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

351 
WUUS51 KPHI 072157
SVRPHI
NJC019-021-041-PAC011-017-029-045-077-091-095-101-072300-
/O.NEW.KPHI.SV.W.0079.120707T2157Z-120707T2300Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
557 PM EDT SAT JUL 7 2012

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  MERCER COUNTY IN CENTRAL NEW JERSEY...
  THIS INCLUDES THE CITY OF TRENTON...
  BERKS COUNTY IN EASTERN PENNSYLVANIA...
  THIS INCLUDES THE CITY OF READING...
  LEHIGH COUNTY IN EASTERN PENNSYLVANIA...
  THIS INCLUDES THE CITY OF ALLENTOWN...
  CENTRAL NORTHAMPTON COUNTY IN EASTERN PENNSYLVANIA...
  THIS INCLUDES THE CITY OF EASTON...
  SOUTHERN HUNTERDON COUNTY IN NORTHWEST NEW JERSEY...
  SOUTHWESTERN WARREN COUNTY IN NORTHWEST NEW JERSEY...
  BUCKS COUNTY IN SOUTHEAST PENNSYLVANIA...
  NORTHERN CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA...
  THIS INCLUDES THE CITY OF WEST CHESTER...
  DELAWARE COUNTY IN SOUTHEAST PENNSYLVANIA...
  MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA...
  PHILADELPHIA COUNTY IN SOUTHEAST PENNSYLVANIA...
  THIS INCLUDES THE CITY OF PHILADELPHIA...

* UNTIL 700 PM EDT

* AT 556 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 6 MILES NORTHEAST OF BEERSVILLE
  TO BETHLEHEM TO 10 MILES NORTHWEST OF WOMELSDORF...AND MOVING 
  SOUTHEAST AT 40 MPH.

* SEVERE THUNDERSTORMS WILL BE NEAR...
  BELFAST...ZIONSVILLE...WOMELSDORF AND NAZARETH AROUND 605 PM EDT...
  TATAMY...SPRINGTOWN...PLEASANT VALLEY AND GERYVILLE AROUND 610 PM
  EDT...
  REVERE AND FERNDALE AROUND 615 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

PLEASE REPORT HAIL OR STRONG WINDS TO THE NATIONAL WEATHER SERVICE BY
CALLING TOLL FREE...1-877-633-6772...WHEN YOU CAN DO SO SAFELY.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 700 PM EDT
SATURDAY EVENING FOR NORTHERN NEW JERSEY AND EASTERN PENNSYLVANIA.

&&

LAT...LON 4049 7643 4058 7572 4073 7551 4081 7550
      4086 7531 4051 7479 4038 7472 4039 7466
      4017 7460 4015 7464 4018 7471 4013 7474
      4013 7482 4008 7487 4004 7498 3989 7520
      3984 7541 3992 7568 4008 7594 4014 7589
TIME...MOT...LOC 2157Z 309DEG 40KT 4081 7539 4066 7538
          4051 7560 4042 7635

$$

HAYES
2 follow-up statements
760 
WWUS51 KPHI 072222
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
622 PM EDT SAT JUL 7 2012

NJC019-021-041-PAC011-017-029-045-077-091-095-101-072300-
/O.CON.KPHI.SV.W.0079.000000T0000Z-120707T2300Z/
WARREN NJ-HUNTERDON NJ-MERCER NJ-BERKS PA-BUCKS PA-LEHIGH PA-
MONTGOMERY PA-PHILADELPHIA PA-DELAWARE PA-NORTHAMPTON PA-CHESTER PA-
622 PM EDT SAT JUL 7 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 700 PM EDT
FOR NORTHERN CHESTER...SOUTHERN NORTHAMPTON...DELAWARE...
PHILADELPHIA...MONTGOMERY...LEHIGH...BUCKS...BERKS...MERCER...
HUNTERDON AND SOUTHWESTERN WARREN COUNTIES...

AT 617 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 ALPHA TO REVERE TO
TRUMBAUERSVILLE TO WERNERSVILLE...OR ALONG A LINE EXTENDING FROM
EASTON TO 13 MILES SOUTH OF EASTON TO 17 MILES SOUTH OF ALLENTOWN TO
11 MILES WEST OF READING...MOVING SOUTHEAST AT 45 MPH.

SEVERE THUNDERSTORMS WILL BE NEAR...
  NEW MORGAN...LUMBERVILLE...GARDENVILLE AND CEDARVILLE BY 630 PM
  EDT...
  PUGHTOWN...SERGEANTSVILLE...TRAPPE AND SPRING CITY BY 635 PM EDT...
  FLEMINGTON AND SAND BROOK BY 640 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

PLEASE REPORT HAIL OR STRONG WINDS TO THE NATIONAL WEATHER SERVICE BY
CALLING TOLL FREE...1-877-633-6772...WHEN YOU CAN DO SO SAFELY.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 700 PM EDT
SATURDAY EVENING FOR NORTHERN NEW JERSEY AND EASTERN PENNSYLVANIA. A
SEVERE THUNDERSTORM WATCH ALSO REMAINS IN EFFECT UNTIL MIDNIGHT EDT
SUNDAY MORNING FOR NORTHERN DELAWARE AND NORTHEAST MARYLAND AND NEW
JERSEY AND SOUTHEASTERN PENNSYLVANIA.

&&

LAT...LON 4058 7572 4081 7524 4051 7479 4038 7472
      4039 7466 4017 7461 4015 7464 4018 7471
      4013 7474 4013 7482 4008 7487 4004 7498
      3989 7520 3984 7541 3992 7568 4008 7594
      4014 7589 4044 7635
TIME...MOT...LOC 2221Z 309DEG 40KT 4063 7512 4048 7512
          4033 7534 4025 7609

$$

HAYES
704 
WWUS51 KPHI 072235
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
635 PM EDT SAT JUL 7 2012

NJC019-021-041-PAC011-017-029-045-077-091-095-101-072300-
/O.CON.KPHI.SV.W.0079.000000T0000Z-120707T2300Z/
WARREN NJ-HUNTERDON NJ-MERCER NJ-BERKS PA-BUCKS PA-LEHIGH PA-
MONTGOMERY PA-PHILADELPHIA PA-DELAWARE PA-NORTHAMPTON PA-CHESTER PA-
635 PM EDT SAT JUL 7 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 700 PM EDT
FOR NORTHERN CHESTER...SOUTH CENTRAL NORTHAMPTON...DELAWARE...
PHILADELPHIA...MONTGOMERY...SOUTHEASTERN LEHIGH...BUCKS...SOUTHERN
BERKS...MERCER...SOUTHERN HUNTERDON AND SOUTHWESTERN WARREN
COUNTIES...

AT 630 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
FRENCHTOWN TO LUMBERVILLE TO MONTGOMERYVILLE TO 7 MILES WEST OF NEW 
MORGAN...MOVING SOUTHEAST AT 45 MPH.

A WIND GUST TO 68 MPH HAS OCCURRED WITH THESE THUNDERSTORMS IN SOUTH 
ALLENTOWN PENNSYLVANIA.

SEVERE THUNDERSTORMS WILL BE NEAR...
  FLEMINGTON...SAND BROOK...WARMINSTER HEIGHTS AND TROOPER BY 640 PM
  EDT...
  GLENMOORE...CHESTER SPRINGS...WILLOW GROVE AND WEST NORRITON BY 645
  PM EDT...
  VALLEY FORGE AND ABINGTON BY 650 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

PLEASE REPORT HAIL OR STRONG WINDS TO THE NATIONAL WEATHER SERVICE BY
CALLING TOLL FREE...1-877-633-6772...WHEN YOU CAN DO SO SAFELY.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 700 PM EDT
SATURDAY EVENING FOR NORTHERN NEW JERSEY AND EASTERN PENNSYLVANIA. A
SEVERE THUNDERSTORM WATCH ALSO REMAINS IN EFFECT UNTIL MIDNIGHT EDT
SUNDAY MORNING FOR NORTHERN DELAWARE AND NORTHEAST MARYLAND AND NEW
JERSEY AND SOUTHEASTERN PENNSYLVANIA.

&&

LAT...LON 4037 7621 4051 7566 4070 7510 4051 7479
      4038 7472 4039 7466 4017 7461 4015 7464
      4018 7471 4013 7474 4013 7482 4008 7487
      4004 7498 3997 7512 3989 7520 3984 7541
      3992 7568 4008 7594 4014 7589
TIME...MOT...LOC 2234Z 309DEG 40KT 4053 7498 4038 7498
          4023 7520 4016 7595

$$

HAYES

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 7, 12:30 PM EDTSpecial Weather StatementPHIMorris, Sussex90 min
Jul 7, 6:25 PM EDTSevere Thunderstorm WarningPHIHunterdon, Somerset, Warren37 min
Jul 7, 6:54 PM EDTSevere Thunderstorm WarningPHIMercer, Middlesex, Monmouth, Ocean, Somerset46 min
Jul 7, 7:03 PM EDTSpecial Weather StatementPHIBurlington, Camden, Gloucester57 min
Jul 7, 7:22 PM EDTSevere Thunderstorm WarningPHIMonmouth, Ocean53 min
Jul 7, 7:24 PM EDTSpecial Marine WarningPHI96 min
Jul 7, 7:42 PM EDTSevere Thunderstorm WarningPHIBurlington, Ocean63 min
Jul 7, 7:55 PM EDTSpecial Weather StatementPHIAtlantic65 min
Jul 7, 4:49 PM EDTSpecial Weather StatementPHIBerks, Carbon, Lehigh, Northampton86 min
Jul 7, 5:07 PM EDTSevere Thunderstorm WarningPHIBerks, Carbon, Lehigh, Monroe, Northampton53 min
Jul 7, 6:58 PM EDTSevere Thunderstorm WarningPHIBerks, Chester, Delaware, Montgomery48 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2012Severe Thunderstorm Warnings in New Jersey, 2012Every severe thunderstorm warning in 2012

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.