Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2010

Severe Thunderstorm Warning 76, NWS Philadelphia/Mount Holly

June 24, 20104 counties in Pennsylvania; New Castle County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jun 24, 2010, 2:56 PM EDT for 4 counties in Pennsylvania; New Castle County, Delaware. It was in force for 64 min. 15 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 24, 2010, 2:56 PM EDT (18:56 UTC)
Expired
Jun 24, 2010, 4:00 PM EDT
In force
64 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

Counties New Castle County, DE, Chester 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 18:58 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 24, 3:20 PM EDTHAIL 12 Ssw Aldan, PAQUARTER SIZE HAIL IN HAVERTOWN
Jun 24, 3:20 PM EDTHAIL 1Ridley Park, PAQUARTER SIZE HAIL IN RIDLEY CREEK STATE PARK
Jun 24, 3:25 PM EDTHAIL 12 Sw Morris Park, PAQUARTER SIZE HAIL IN UPPER DARBY
Jun 24, 3:28 PM EDTHAIL 1Lansdowne, PAQUARTER SIZE HAIL IN LANSDOWNE
Jun 24, 3:30 PM EDTTSTM WND DMGClifton Heights, PANUMEROUS LARGE TREES DOWN WITH PROPERTY DAMAGE IN CLIFTON HEIGHTS.
Jun 24, 3:30 PM EDTTSTM WND DMGNne Newtown Grant, PATREES DOWN, TRAFFIC LIGHTS OUT.
Jun 24, 3:30 PM EDTTSTM WND DMGPhiladelphia, PASEVERAL LARGE TREES DOWN NEAR CITIZENS BANK BALL PARK IN PHILADELPHIA.
Jun 24, 3:30 PM EDTTSTM WND DMGSharon Hill, PATREE BLOCKING CALCON HOOK ROAD
Jun 24, 3:30 PM EDTTSTM WND DMGSpringfield, PANUMEROUS LARGE TREES DOWN WITH PROPERTY DAMAGE IN SPRINGFIELD
Jun 24, 3:30 PM EDTTSTM WND GST 76Drexel Hill, PA76 MPH WIND GUST MEASURED WITH SEVERAL TREES DOWN ON HOUSES AND GARAGE CRUSHED IN DREXEL HILL
Jun 24, 3:30 PM EDTHAIL 1Philadelphia, PAQUARTER SIZE HAIL ALONG WITH NUMEROUS TREES DOWN IN CLARK PARK AND OTHER PORTIONS OF THE CITY.
Jun 24, 3:30 PM EDTHAIL 1.5Drexel Hill, PA1 AND A HALF INCH HAIL IN DREXEL HILL WITH TREES DOWN AND CAR WINDOWS BLOWN OUT.
Jun 24, 3:30 PM EDTHAIL 1.75Yeadon, PAGOLF BALL SIZE HAIL IN YEADON
Jun 24, 3:31 PM EDTTSTM WND GST 75Philadelphia Intl Airpo, PA65 KNOTS MEASURED AT PHILADELPHIA INTL AIRPORT
Jun 24, 4:00 PM EDTTSTM WND DMGPhiladelphia Intl Airpo, PATREES AND POWER WIRES DOWN, ALONG WITH TROLLY WIRES KNOCKED DOWN IN UNIVERSITY CITY AREA OF PHILADELPHIA

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 24, 12:28 PM EDTSevere Thunderstorm WatchSPC8 hr

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 6.9 hours before the alert went out and 81 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 2010-06-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 126 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 2010-06-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 133 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
126 J/kg
Mixed-layer CIN
-170 J/kg
Mixed-layer LCL
1592 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
133 m²/s²
0-3 km storm-relative helicity
65 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.

848 
WUUS51 KPHI 241856
SVRPHI
DEC003-PAC029-045-091-101-242000-
/O.NEW.KPHI.SV.W.0076.100624T1856Z-100624T2000Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
256 PM EDT THU JUN 24 2010

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHERN NEW CASTLE COUNTY IN NORTHERN DELAWARE...
  THIS INCLUDES THE CITY OF WILMINGTON...
  SOUTHEASTERN CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA...
  THIS INCLUDES THE CITY OF WEST CHESTER...
  DELAWARE COUNTY IN SOUTHEAST PENNSYLVANIA...
  SOUTHEASTERN MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA...
  PHILADELPHIA COUNTY IN SOUTHEAST PENNSYLVANIA...
  THIS INCLUDES THE CITY OF PHILADELPHIA...

* UNTIL 400 PM EDT

* AT 254 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING DESTRUCTIVE WINDS IN
  EXCESS OF 70 MPH.  THIS STORM WAS LOCATED 14 MILES NORTHWEST OF
  WEST CHESTER...AND MOVING EAST AT 50 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  PAOLI AND VALLEY FORGE AROUND 310 PM EDT...
  KING OF PRUSSIA AROUND 315 PM EDT...
  RADNOR TOWNSHIP...TROUT LAKE...NEWTOWN SQUARE AND BROOMALL AROUND
  320 PM EDT...
  NARBERTH...BRYN MAWR AND MORRIS PARK AROUND 325 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS STORM HAS A HISTORY OF PRODUCING WIDESPREAD WIND DAMAGE. THIS 
IS AN EXTREMELY DANGEROUS SITUATION. SEEK SHELTER NOW INSIDE A 
STURDY STRUCTURE AND STAY AWAY FROM WINDOWS!

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 600 PM EDT
THURSDAY EVENING FOR NORTHEAST PENNSYLVANIA. A SEVERE THUNDERSTORM
WATCH ALSO REMAINS IN EFFECT UNTIL 800 PM EDT THURSDAY EVENING FOR
DELAWARE AND NORTHEASTERN MARYLAND AND NEW JERSEY AND SOUTHEASTERN
PENNSYLVANIA.

&&

LAT...LON 3976 7583 4028 7533 4022 7515 4011 7497
      4003 7499 3995 7514 3989 7514 3988 7515
      3985 7525 3984 7537 3979 7542 3976 7547
      3972 7548 3969 7552
TIME...MOT...LOC 1855Z 285DEG 45KT 4011 7576

$$

KRUZDLO
1 follow-up statement
381 
WWUS51 KPHI 241918
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
318 PM EDT THU JUN 24 2010

DEC003-PAC029-045-091-101-242000-
/O.CON.KPHI.SV.W.0076.000000T0000Z-100624T2000Z/
DELAWARE PA-PHILADELPHIA PA-CHESTER PA-MONTGOMERY PA-NEW CASTLE DE-
318 PM EDT THU JUN 24 2010

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 400 PM EDT
FOR NORTHERN NEW CASTLE...SOUTHEASTERN MONTGOMERY...SOUTHEASTERN
CHESTER...PHILADELPHIA AND DELAWARE COUNTIES...

AT 315 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING DESTRUCTIVE WINDS
IN EXCESS OF 70 MPH.  THIS STORM WAS LOCATED NEAR NEWTOWN SQUARE...OR
11 MILES EAST OF WEST CHESTER...MOVING SOUTHEAST AT 55 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  DARBY...COLWYN...COLLINGDALE AND SOUTH PHILADELPHIA BY 325 PM
  EDT...
  7 MILES SOUTHWEST OF CENTER CITY...7 MILES SOUTHWEST OF KENSINGTON
  AND 8 MILES SOUTHWEST OF PHILADELPHIA BY 330 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS STORM HAS A HISTORY OF PRODUCING WIDESPREAD WIND DAMAGE. THIS 
IS AN EXTREMELY DANGEROUS SITUATION. SEEK SHELTER NOW INSIDE A 
STURDY STRUCTURE AND STAY AWAY FROM WINDOWS!

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 600 PM EDT
THURSDAY EVENING FOR NORTHEAST PENNSYLVANIA. A SEVERE THUNDERSTORM
WATCH ALSO REMAINS IN EFFECT UNTIL 800 PM EDT THURSDAY EVENING FOR
DELAWARE AND NORTHEASTERN MARYLAND AND NEW JERSEY AND SOUTHEASTERN
PENNSYLVANIA.

&&

LAT...LON 3976 7583 4028 7533 4022 7515 4011 7497
      4003 7499 3995 7514 3989 7514 3988 7515
      3985 7525 3984 7537 3979 7542 3976 7547
      3972 7548 3969 7552
TIME...MOT...LOC 1917Z 294DEG 48KT 3995 7537

$$

KRUZDLO

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 24, 12:36 PM EDTSpecial Weather StatementPHIMonroe54 min
Jun 24, 1:16 PM EDTSpecial Weather StatementPHIMonroe59 min
Jun 24, 1:59 PM EDTSevere Thunderstorm WarningPHIBerks66 min
Jun 24, 2:31 PM EDTSevere Thunderstorm WarningPHIChester, Montgomery59 min
Jun 24, 3:13 PM EDTSevere Thunderstorm WarningPHIBucks62 min
Jun 24, 3:29 PM EDTSevere Thunderstorm WarningPHIChester61 min
Jun 24, 4:18 PM EDTSevere Thunderstorm WarningPHINew Castle57 min
Jun 24, 5:18 PM EDTSevere Thunderstorm WarningPHIKent, Sussex87 min
Jun 24, 5:46 PM EDTSevere Thunderstorm WarningPHIKent59 min
Jun 24, 6:53 PM EDTSpecial Weather StatementPHISussex67 min
Jun 24, 7:14 PM EDTSevere Thunderstorm WarningPHISussex50 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2010Severe Thunderstorm Warnings in Delaware, 2010Every severe thunderstorm warning in 2010

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.