Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 1988

Severe Thunderstorm Warning 45, NWS Philadelphia/Mount Holly

August 26, 1988Chester County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 26, 1988, 6:49 PM EDT for Chester County, Pennsylvania. It was in force for 41 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Aug 26, 1988, 6:49 PM EDT (22:49 UTC)
Expired
Aug 26, 1988, 7:30 PM EDT
In force
41 min
Issued by
NWS Philadelphia/Mount Holly
Area
Whole counties

County Chester County, PA

The radar

The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.

What was reported inside it

TimeReportWhereRemark
Aug 26, 7:00 PM EDTThunderstorm Wind 0Chester, PA

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in. Storm Data before 1996 records only tornadoes, thunderstorm wind and hail.

The nearest sounding before it

Atlantic City In, NJ (KACY), launched 12:00Z, 10.8 hours before the alert went out and 122 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, Atlantic City In, NJ at 12:00Z on 1988-08-26Temperature 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, Atlantic City In, NJ at 12:00Z on 1988-08-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 35 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
NaN m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
35 m²/s²
0-3 km storm-relative helicity
48 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.8

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KPHL 262249
SVRPHL
PAC029-262330-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING 
NATIONAL WEATHER SERVICE PHILADELPHIA PA
649 PM EDT FRI AUG 26 1988

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM 
WARNING EFFECTIVE UNTIL 730 PM EDT FOR PEOPLE IN THE FOLLOWING 
COUNTY

   IN THE SOUTHEAST PART OF PENNSYLVANIA
      SOUTHERN CHESTER

AT 645 PM EDT RADAR INDICATED AN INTENSE THUNDERSTORM
OVER SOUTHWESTERN CHESTER COUNTY. THE THUNDERSTORM WAS
MOVING TOWARD THE EAST AT 30 MILES AN HOUR.

 THIS IS A DANGEROUS STORM AND PEOPLE IN THE WARNED AREA SHOULD BE
PREPARED FOR STRONG DAMAGING WINDS...LARGE HAIL...VERY HEAVY RAIN
AND LIGHTNING. SHOULD THE STORM APPROACH YOU...SEEK IMMEDIATE
SHELTER. MOBILE HOMES ARE MOST VULNERABLE TO HIGH WINDS AND
SHOULD BE AVOIDED.

 SP

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

In the hours before

Special weather statement, Aug 26, 6:03 PM EDT, 46 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PHILADELPHIA, PA
601 PM EDT FRI AUG 26 1988

...THUNDERSTORMS APPROACHING SOUTHERN CHESTER COUNTY PENNSYLVANIA...

     AT 6 PM WEATHER SERVICE RADAR SHOWED STRONG THUNDERSTORMS OVER
SOUTHWEST LANCASTER COUNTY.  THESE THUNDERSTORMS WERE MOVING EAST
AROUND 30 MPH AND WILL PROBABLY MOVE INTO SOUTHERN CHESTER COUNTY
BETWEEN 615 AND 630 PM.

     THESE THUNDERSTORMS MAY BE ACCOMPANIED BY GUSTY WINDS...LOCALLY
HEAVY RAIN...AND FREQUENT LIGHTNING.

IF THREATENING WEATHER IS SIGHTED SEEK SHELTER IMMEDIATELY.

SP
Special weather statement, Aug 26, 6:38 PM EDT, 11 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PHILADELPHIA, PA
637 PM EDT FRI AUG 26 1988

...STRONG THUNDERSTORM MOVING INTO SOUTHWEST CHESTER COUNTY
   PENNSYLVANIA...

     AT 6.30 PM WEATHER SERVICE RADAR SHOWED A STRONG THUNDERSTORM
NEAR THE SOUTHERN LANCASTER...SOUTHERN CHESTER COUNTY BORDER.  THIS
THUNDERSTORM MAY BE ACCOMPANIED BY STRONG GUSTY WINDS...HAIL...
HEAVY RAIN...AND FREQUENT LIGHTNING.

     THIS STORM WILL MOVE EAST THROUGH SOUTHERN CHESTER COUNTY AT
AROUND 30 MPH BETWEEN NOW AND 730 PM.

     IF THREATENING WEATHER IS SIGHTED SEEK SHELTER IMMEDIATELY.

SP

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 1988Every severe thunderstorm warning in 1988

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.