Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2007

Severe Thunderstorm Warning 146, NWS Philadelphia/Mount Holly

July 27, 2007Chester County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 27, 2007, 6:42 PM EDT for Chester County, Pennsylvania. It was in force for 93 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: Jul 27, 2007, 6:42 PM EDT (22:42 UTC)
Expired: Jul 27, 2007, 8:15 PM EDT
In force: 93 min
Issued by: NWS Philadelphia/Mount Holly
Area: Counties, with a storm outline in the text

County Chester County, PA

What was reported inside it

Time	Report	Where	Remark
Jul 27, 7:45 PM EDT	TSTM WND DMG	5 Nne Kennett Square, PA	A COUPLE OF WIRES KNOCKED DOWN IN POCOPSON TWP AND CENTRAL CHESTER COUNTY.

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

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 10.7 hours before the alert went out and 50 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1522 J/kg
Mixed-layer CIN: -30 J/kg
Mixed-layer LCL: 651 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: 27 m²/s²
0-3 km storm-relative helicity: 47 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.6

Open this sounding in Storm Lab

The text

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

000 
WUUS51 KPHI 272243
SVRPHI
PAC029-280015-
/O.NEW.KPHI.SV.W.0146.070727T2242Z-070728T0015Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
642 PM EDT FRI JUL 27 2007

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA...

* UNTIL 815 PM EDT

* AT 636 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING PENNY SIZE
  HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THESE STORMS WERE
  LOCATED ALONG A LINE EXTENDING FROM 7 MILES NORTHWEST OF HONEY
  BROOK TO 9 MILES WEST OF GLEN ROY...OR ALONG A LINE EXTENDING FROM
  12 MILES SOUTH OF READING TO 22 MILES SOUTH OF LANCASTER...AND
  MOVING EAST AT 15 MPH.

* SEVERE THUNDERSTORMS WILL BE NEAR...
  HONEY BROOK BY 655 PM EDT...
  MOUNT VERNON AND GLEN ROY BY 700 PM EDT...
  ELVERSON AND HOMEVILLE BY 705 PM EDT...
  PARKESBURG AND OXFORD BY 710 PM EDT...
  COCHRANVILLE BY 715 PM EDT...
  GLENMOORE AND COATESVILLE BY 720 PM EDT...

THUNDERSTORMS ARE CAPABLE OF PRODUCING HEAVY RAINFALL WHICH MAY
RESULT IN LOCALIZED AREAS OF FLOODING. DO NOT DRIVE IN AREAS WHERE
WATER IS CROSSING THE ROAD.

LAT...LON 3975 7609 3985 7603 3987 7599 3992 7601
      3993 7599 3997 7599 4004 7594 4011 7594
      4020 7579 4008 7543 3974 7580 3974 7611
      3975 7611 3974 7613

$$

SZATKOWSKI

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 27, 5:36 PM EDT	Severe Thunderstorm Warning	PHI	Berks	84 min
Jul 27, 7:31 PM EDT	Severe Thunderstorm Warning	PHI	Monroe, Northampton	59 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2007 Every 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.