Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2015

Severe Thunderstorm Warning 94, NWS Philadelphia/Mount Holly

July 9, 20154 counties in New Jersey; 5 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 9, 2015, 7:39 PM EDT for 4 counties in New Jersey; 5 counties in Pennsylvania. It was in force for 66 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 9, 2015, 7:39 PM EDT (23:39 UTC)
Expired
Jul 9, 2015, 8:45 PM EDT
In force
66 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

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

The radar

The Philadelphia radar (KDIX), 52 km from the middle of the area, began a volume at 23:38 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 9, 8:00 PM EDTTSTM WND DMGAston Arms, PATREES DOWN SEVERAL LOCATIONS AROUND THE COUNTY.
Jul 9, 8:18 PM EDTTSTM WND DMGPhiladelphia, PALARGE TREE DOWN ON A BUILDING IN WASHINGTON SQUARE

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 9, 4:57 PM EDTSevere Thunderstorm WatchSPC5 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 11.7 hours before the alert went out and 189 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 2015-07-09Temperature 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, Brookhaven, NY at 12:00Z on 2015-07-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 30 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
757 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
30 m²/s²
0-3 km storm-relative helicity
129 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.

926 
WUUS51 KPHI 092339
SVRPHI
NJC005-007-015-021-PAC017-029-045-091-101-100045-
/O.NEW.KPHI.SV.W.0094.150709T2339Z-150710T0045Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
739 PM EDT THU JUL 9 2015

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ  HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  MERCER COUNTY IN CENTRAL NEW JERSEY...
  NORTHWESTERN CAMDEN COUNTY IN SOUTHERN NEW JERSEY...
  NORTHWESTERN GLOUCESTER COUNTY IN SOUTHERN NEW JERSEY...
  NORTHERN BURLINGTON COUNTY IN SOUTHERN NEW JERSEY...
  DELAWARE COUNTY IN SOUTHEASTERN PENNSYLVANIA...
  EAST CENTRAL CHESTER COUNTY IN SOUTHEASTERN PENNSYLVANIA...
  SOUTHEASTERN BUCKS COUNTY IN SOUTHEASTERN PENNSYLVANIA...
  PHILADELPHIA COUNTY IN SOUTHEASTERN PENNSYLVANIA...
  SOUTHEASTERN MONTGOMERY COUNTY IN SOUTHEASTERN PENNSYLVANIA...

* UNTIL 845 PM EDT

* AT 738 PM EDT...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 REVERE
  TO DOYLESTOWN TO NEAR AMBLER TO NEAR PAOLI...AND MOVING EAST AT 45
  MPH.

* LOCATIONS IMPACTED INCLUDE...
  PHILADELPHIA...TRENTON...CAMDEN...GLOUCESTER CITY...CHERRY HILL...
  BENSALEM...MOUNT LAUREL...EWING...CHESTER...WILLINGBORO...
  LANSDALE...EAST NORRITON...LUMBERTON...PRINCETON...FLORENCE...
  BELLMAWR...YEADON...BURLINGTON...BRISTOL AND MOUNT HOLLY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WINDS...LARGE HAIL...DEADLY
LIGHTNING AND VERY HEAVY RAIN. FOR YOUR PROTECTION...MOVE TO AN
INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR HOME OR BUSINESS. HEAVY
RAINS FLOOD ROADS QUICKLY SO DO NOT DRIVE INTO AREAS WHERE WATER
COVERS THE ROAD.

IN ADDITION TO DAMAGING WINDS...FREQUENT CLOUD TO GROUND LIGHTNING 
IS OCCURRING WITH THIS STORM. MOVE INDOORS IMMEDIATELY. 
REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE 
STRUCK BY LIGHTNING.

&&

LAT...LON 3980 7541 3994 7553 4011 7531 4033 7528
      4036 7494 4034 7494 4035 7485 4037 7486
      4039 7467 4038 7462 4034 7463 4030 7457
      4020 7455 4018 7461 4002 7452
TIME...MOT...LOC 2338Z 268DEG 38KT 4050 7515 4029 7514 4012 7518 4000
7550

$$

GORSE
2 follow-up statements
958 
WWUS51 KPHI 100008
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
808 PM EDT THU JUL 9 2015

NJC005-007-015-021-PAC017-029-045-091-101-100045-
/O.CON.KPHI.SV.W.0094.000000T0000Z-150710T0045Z/
MERCER NJ-CAMDEN NJ-GLOUCESTER NJ-BURLINGTON NJ-DELAWARE PA-
CHESTER PA-BUCKS PA-PHILADELPHIA PA-MONTGOMERY PA-
808 PM EDT THU JUL 9 2015

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 845 PM EDT
FOR MERCER...NORTHWESTERN CAMDEN...NORTHWESTERN GLOUCESTER...NORTHERN
BURLINGTON...DELAWARE...EAST CENTRAL CHESTER...SOUTHEASTERN BUCKS...
PHILADELPHIA AND SOUTHEASTERN MONTGOMERY COUNTIES...

AT 805 PM EDT...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 NEAR 
CLOVERHILL TO YARDLEY TO BURLINGTON TO FOLCROFT...MOVING EAST AT 45 
MPH.

AN AREA OF STRONG WIND INDICATED BY DOPPLER RADAR IS MOVING ACROSS 
LOWER BUCKS COUNTY AND INTO BURLINGTON COUNTY, WITH ANOTHER AREA OF 
STRONG WINDS MOVING ACROSS DELAWARE COUNTY TOWARD PHILADELPHIA.

LOCATIONS IMPACTED INCLUDE...
PHILADELPHIA...TRENTON...CAMDEN...GLOUCESTER CITY...CHERRY HILL...
BENSALEM...MOUNT LAUREL...EWING...CHESTER...WILLINGBORO...LANSDALE...
EAST NORRITON...LUMBERTON...PRINCETON...FLORENCE...BELLMAWR...
YEADON...BURLINGTON...BRISTOL AND MOUNT HOLLY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WINDS...DEADLY LIGHTNING AND 
VERY HEAVY RAIN. FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE 
LOWEST FLOOR OF YOUR HOME OR BUSINESS. HEAVY RAINS FLOOD ROADS 
QUICKLY SO DO NOT DRIVE INTO AREAS WHERE WATER COVERS THE ROAD.

IN ADDITION TO DAMAGING WINDS...FREQUENT CLOUD TO GROUND LIGHTNING 
IS OCCURRING WITH THESE STORMS. MOVE INDOORS IMMEDIATELY. 
REMEMBER... IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE 
STRUCK BY LIGHTNING.

&&

LAT...LON 3980 7541 3994 7553 4011 7531 4033 7528
      4036 7494 4034 7494 4035 7485 4037 7486
      4039 7467 4038 7462 4034 7463 4030 7457
      4020 7455 4018 7461 4002 7452
TIME...MOT...LOC 0005Z 280DEG 36KT 4045 7482 4024 7481 4007 7485 3989
7528

$$

GORSE
962 
WWUS51 KPHI 100036
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
836 PM EDT THU JUL 9 2015

PAC029-045-100045-
/O.CAN.KPHI.SV.W.0094.000000T0000Z-150710T0045Z/
DELAWARE PA-CHESTER PA-
836 PM EDT THU JUL 9 2015

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

THE STORMS WHICH PROMPTED THE WARNING HAVE MOVED OUT OF THE AREA. 
THEREFORE THE WARNING HAS BEEN CANCELLED.

LAT...LON 3987 7514 4036 7494 4034 7494 4035 7485
      4037 7486 4039 7467 4038 7462 4034 7463
      4030 7457 4020 7455 4018 7461 4002 7452
TIME...MOT...LOC 0035Z 277DEG 27KT 4042 7454 4021 7453 4004 7457 3986
7500

$$

NJC005-007-015-021-PAC017-091-101-100045-
/O.CON.KPHI.SV.W.0094.000000T0000Z-150710T0045Z/
MERCER NJ-CAMDEN NJ-GLOUCESTER NJ-BURLINGTON NJ-BUCKS PA-
PHILADELPHIA PA-MONTGOMERY PA-
836 PM EDT THU JUL 9 2015

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 845 PM EDT
FOR MERCER...NORTHWESTERN CAMDEN...NORTHERN GLOUCESTER...NORTHERN
BURLINGTON...SOUTHEASTERN BUCKS...NORTHEASTERN PHILADELPHIA AND
SOUTHEASTERN MONTGOMERY COUNTIES...

AT 835 PM EDT...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 KENDALL
PARK TO NEAR ROOSEVELT TO NEAR WRIGHTSTOWN TO ECHELON...MOVING EAST
AT 35 MPH.

LOCATIONS IMPACTED INCLUDE...

TRENTON...CAMDEN...GLOUCESTER CITY...BENSALEM...MOUNT 
LAUREL...EWING...WILLINGBORO...LUMBERTON...PRINCETON...FLORENCE... 
BURLINGTON...BRISTOL...MOUNT HOLLY...RIVERSIDE...PALMYRA... 
WESTVILLE...BORDENTOWN...PENNINGTON AND BEVERLY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WINDS...DEADLY LIGHTNING AND 
VERY HEAVY RAIN. FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE 
LOWEST FLOOR OF YOUR HOME OR BUSINESS. HEAVY RAINS FLOOD ROADS 
QUICKLY SO DO NOT DRIVE INTO AREAS WHERE WATER COVERS THE ROAD.

IN ADDITION TO DAMAGING WINDS...FREQUENT CLOUD TO GROUND LIGHTNING 
IS OCCURRING WITH THIS STORM.  MOVE INDOORS IMMEDIATELY.  
REMEMBER... IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE 
STRUCK BY LIGHTNING.

&&

LAT...LON 3987 7514 4036 7494 4034 7494 4035 7485
      4037 7486 4039 7467 4038 7462 4034 7463
      4030 7457 4020 7455 4018 7461 4002 7452
TIME...MOT...LOC 0035Z 277DEG 27KT 4042 7454 4021 7453 4004 7457 3986
7500

$$

GORSE

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 9, 7:12 PM EDTSevere Thunderstorm WarningPHIHunterdon, Warren48 min
Jul 9, 7:29 PM EDTSevere Thunderstorm WarningPHISalem46 min
Jul 9, 7:44 PM EDTSpecial Marine WarningPHI31 min
Jul 9, 7:55 PM EDTSevere Thunderstorm WarningPHIBurlington, Camden, Cumberland, Gloucester, Salem40 min
Jul 9, 7:56 PM EDTAreal Flood AdvisoryPHIBurlington, Camden, Gloucester, Hunterdon, Mercer, Ocean4 hr
Jul 9, 6:15 PM EDTSevere Thunderstorm WarningPHIBerks, Chester, Montgomery45 min
Jul 9, 6:35 PM EDTSevere Thunderstorm WarningPHIBerks, Lehigh40 min
Jul 9, 6:46 PM EDTAreal Flood AdvisoryPHICarbon, Lehigh, Monroe, Northampton4 hr
Jul 9, 6:50 PM EDTSevere Thunderstorm WarningPHIChester40 min
Jul 9, 6:57 PM EDTSevere Thunderstorm WarningPHIBerks, Bucks, Chester, Lehigh, Montgomery48 min
Jul 9, 7:21 PM EDTAreal Flood AdvisoryPHIBerks, Lehigh4 hr

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2015Severe Thunderstorm Warnings in New Jersey, 2015Every severe thunderstorm warning in 2015

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.