Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2007

Severe Thunderstorm Warning 24, NWS Philadelphia/Mount Holly

May 27, 20074 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at May 27, 2007, 9:27 PM EDT for 4 counties in Pennsylvania. It was in force for 63 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
May 27, 2007, 9:27 PM EDT (01:27 UTC)
Expired
May 27, 2007, 10:30 PM EDT
In force
63 min
Issued by
NWS Philadelphia/Mount Holly
Area
Counties, with a storm outline in the text

Counties Chester County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA

What was reported inside it

TimeReportWhereRemark
May 27, 9:41 PM EDTTSTM WND DMGChesterbrook, PATREES AND WIRES DOWNED IN TREDYFFRIN
May 27, 9:45 PM EDTTSTM WND DMGRadnor Township, PATREES AND WIRES REPORTED DOWN IN SEVERAL TOWNSHIPS.

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

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 00:00Z, 1.5 hours before the alert went out and 214 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, Washington/Dulle, VA at 00:00Z on 2007-05-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 16 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, Washington/Dulle, VA at 00:00Z on 2007-05-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 118 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
16 J/kg
Mixed-layer CIN
-171 J/kg
Mixed-layer LCL
2137 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
118 m²/s²
0-3 km storm-relative helicity
228 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.

000 
WUUS51 KPHI 280127
SVRPHI
PAC029-045-091-101-280230-
/O.NEW.KPHI.SV.W.0024.070528T0127Z-070528T0230Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
927 PM EDT SUN MAY 27 2007

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EAST CENTRAL CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA...
  DELAWARE COUNTY IN SOUTHEAST PENNSYLVANIA...
  THIS INCLUDES THE CITY OF SPRINGFIELD...
  SOUTHERN MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA...
  PHILADELPHIA COUNTY IN SOUTHEAST PENNSYLVANIA...
  THIS INCLUDES THE CITY OF PHILADELPHIA...

* UNTIL 1030 PM EDT

* AT 920 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 PAOLI...OR ABOUT 8 MILES
  NORTHWEST OF SPRINGFIELD...AND MOVING EAST AT 25 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  EAST LANSDOWNE AND YEADON BY 935 PM EDT...
  ROXBOROUGH...GERMANTOWN...SOUTH PHILADELPHIA AND CHESTNUT HILL BY
  940 PM EDT...
  CENTER CITY AND PHILADELPHIA BY 945 PM EDT...

IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...CONTINUOUS 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.

LAT...LON 4010 7561 3983 7552 3989 7522 4004 7499
      4016 7506 4014 7540

$$

NIERENBERG

The office that day

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

IssuedProductOfficeCountiesLasted
May 27, 8:18 PM EDTSevere Thunderstorm WarningPHIBerks, Chester57 min
May 27, 9:10 PM EDTSevere Thunderstorm WarningPHIBucks50 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2007Every severe thunderstorm warning in 2007

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.