Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 1989

Severe Thunderstorm Warning 23, NWS Philadelphia/Mount Holly

June 15, 1989Chester County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jun 15, 1989, 6:41 PM EDT for Chester County, Pennsylvania. It was in force for 64 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: Jun 15, 1989, 6:41 PM EDT (22:41 UTC)
Expired: Jun 15, 1989, 7:45 PM EDT
In force: 64 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

Time	Report	Where	Remark
Jun 15, 7:25 PM EDT	Thunderstorm Wind 0	Chester, 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, 10.7 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-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: 1 J/kg
Mixed-layer CIN: -247 J/kg
Mixed-layer LCL: 596 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: 138 m²/s²
0-3 km storm-relative helicity: 306 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 
TTAA00 KPHL 152242
SVRPHL
PAC029-152345-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHILADELPHIA PA
641 PM EDT THU JUN 15 1989
 
THE NATIONAL WEATHER SERVICE IN PHILADELPHIA HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  745 PM EDT
FOR PEOPLE IN THE FOLLOWING COUNTY...
 
IN SOUTHEAST PENNSYLVANIA
          ...CHESTER
 
WEATHER SERVICE RADAR AT 640 PM EDT INDICATED A SEVERE THUNDERSTORM
OVER LANCASTER COUNTY NEAR LANCASTER. THIS STORM WAS MOVING NORTHEAST
AT 35 MILES AN HOUR...AND WILL MOVE INTO CHESTER COUNTY OF
SOUTHEASTERN PENNSYLVANIA SHORTLY AROUND 700 PM THIS EVENING...AND
SHOULD MOVE NORTHEAST AND OUT OF CHESTER COUNTY BY 745 PM THIS
EVENING.
 
AT 630 PM...THE PUBLIC REPORTED A TORNADO ON THE GROUND IN THE
VICINITY OF MOUNTVILLE IN WESTERN LANCASTER COUNTY.  IF THIS TORNADO
CONTINUES ON THE GROUND...IT COULD MOVE INTO NORTHERN CHESTER COUNTY
SHORTLY AFTER 700 PM THIS EVENING.
 
THIS IS A DANGEROUS STORM.  IF YOU ARE IN THE WARNED AREA...BE
PREPARED FOR STRONG DAMAGING WINDS...LARGE HAIL...VERY HEAVY RAIN
AND DANGEROUS LIGHTNING.  SHOULD THE STORM APPROACH YOU...SEEK
IMMEDIATE SHELTER.  MOBILE HOMES ARE MOST VULNERABLE TO HIGH WINDS
AND SHOULD BE AVOIDED.
 
WERT

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 1989 Every severe thunderstorm warning in 1989

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.