Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2010

Severe Thunderstorm Warning 7, NWS Philadelphia/Mount Holly

April 8, 20105 counties in Pennsylvania; Burlington County, Camden County, Gloucester County, New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Apr 8, 2010, 9:56 PM EDT for 5 counties in Pennsylvania; Burlington County, Camden County, Gloucester County, New Jersey. It was in force for 28 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 8, 2010, 9:56 PM EDT (01:56 UTC)
Expired
Apr 8, 2010, 10:24 PM EDT
In force
28 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

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

The radar

The Philadelphia radar (KDIX), 56 km from the middle of the area, began a volume at 01:56 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 8, 10:00 PM EDTTSTM WND DMG5 Ene Chelsea, PAWIRES DOWN IN THE ASTON TOWNSHIP AREA.

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

The nearest sounding before it

Brookhaven, NY (KOKX), launched 00:00Z, 1.9 hours before the alert went out and 196 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 00:00Z on 2010-04-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1 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, Brookhaven, NY at 00:00Z on 2010-04-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 202 square meters per square second.19395878Sfc1 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
1 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
916 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
202 m²/s²
0-3 km storm-relative helicity
150 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.

435 
WUUS51 KPHI 090156
SVRPHI
NJC005-007-015-PAC017-029-045-091-101-090245-
/O.NEW.KPHI.SV.W.0007.100409T0156Z-100409T0245Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
956 PM EDT THU APR 8 2010

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHEASTERN BUCKS COUNTY IN SOUTHEAST PENNSYLVANIA...
  EAST CENTRAL CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA...
  DELAWARE COUNTY IN SOUTHEAST PENNSYLVANIA...
  SOUTHEASTERN MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA...
  PHILADELPHIA COUNTY IN SOUTHEAST PENNSYLVANIA...
  THIS INCLUDES THE CITY OF PHILADELPHIA...
  NORTHWESTERN BURLINGTON COUNTY IN SOUTHERN NEW JERSEY...
  NORTHWESTERN CAMDEN COUNTY IN SOUTHERN NEW JERSEY...
  THIS INCLUDES THE CITY OF CAMDEN...
  NORTHWESTERN GLOUCESTER COUNTY IN SOUTHERN NEW JERSEY...

* UNTIL 1045 PM EDT

* AT 950 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS
  OF 60 MPH.  THIS STORM WAS LOCATED NEAR LIMA...OR 8 MILES EAST OF
  WEST CHESTER...AND MOVING NORTHEAST AT 55 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  TROUT LAKE...BRYN MAWR...RADNOR TOWNSHIP AND NARBERTH AROUND 1000
  PM EDT...
  CHESTNUT HILL...CONSHOHOCKEN...PLYMOUTH MEETING AND GERMANTOWN
  AROUND 1005 PM EDT...
  AMBLER AND JENKINTOWN AROUND 1010 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS STORM HAS THE POTENTIAL TO CAUSE SIGNIFICANT WIND DAMAGE.


&&

LAT...LON 3975 7536 3998 7562 4040 7503 4041 7500
      4040 7497 4034 7495 4031 7491 4030 7487
      4024 7484 4015 7472 4017 7469 4006 7458
TIME...MOT...LOC 0154Z 226DEG 50KT 3997 7541

$$

SZATKOWSKI
1 follow-up statement
921 
WWUS51 KPHI 090224
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1024 PM EDT THU APR 8 2010

NJC005-007-015-PAC017-029-045-091-101-090233-
/O.CAN.KPHI.SV.W.0007.000000T0000Z-100409T0245Z/
CAMDEN NJ-GLOUCESTER NJ-DELAWARE PA-PHILADELPHIA PA-CHESTER PA-
MONTGOMERY PA-BUCKS PA-BURLINGTON NJ-
1024 PM EDT THU APR 8 2010

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN BURLINGTON...
SOUTHEASTERN BUCKS...SOUTHEASTERN MONTGOMERY...EAST CENTRAL
CHESTER...PHILADELPHIA...DELAWARE...NORTHWESTERN GLOUCESTER AND
NORTHWESTERN CAMDEN COUNTIES IS CANCELLED...

THE SEVERE THUNDERSTORM HAS WEAKENED AND MOVED OUT OF THE WARNING 
AREA.  THE THREAT OF SEVERE WEATHER HAS ENDED FOR THE WARNING AREA. 


LAT...LON 3975 7536 3998 7562 4040 7503 4041 7500
      4040 7497 4034 7495 4031 7491 4030 7487
      4024 7484 4015 7472 4017 7469 4006 7458
TIME...MOT...LOC 0223Z 226DEG 50KT 4025 7503

$$

SZATKOWSKI

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 8, 9:25 PM EDTSevere Thunderstorm WarningPHIChester, Delaware37 min
Apr 8, 9:24 PM EDTSpecial Marine WarningPHI51 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2010Severe Thunderstorm Warnings in New Jersey, 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.