Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 1992

Severe Thunderstorm Warning 34, NWS Philadelphia/Mount Holly

July 17, 1992Chester County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 17, 1992, 6:43 PM EDT for Chester County, Pennsylvania. It was in force for 47 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
Jul 17, 1992, 6:43 PM EDT (22:43 UTC)
Expired
Jul 17, 1992, 7:30 PM EDT
In force
47 min
Issued by
NWS Philadelphia/Mount Holly
Area
Whole counties

County Chester County, PA

What was reported inside it

TimeReportWhereRemark
Jul 17, 7:30 PM EDTTornado F2Chester, 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-pSkew-T log-p diagram, Atlantic City In, NJ at 12:00Z on 1992-07-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 123 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°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 1992-07-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 44 square meters per square second.1939Sfc1 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
123 J/kg
Mixed-layer CIN
-70 J/kg
Mixed-layer LCL
553 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
44 m²/s²
0-3 km storm-relative helicity
130 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KPHL 172245
SVRPHL
PAC029-172330-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHILADELPHIA PA
643 PM EDT FRI JUL 17 1992
 
THE NATIONAL WEATHER SERVICE IN PHILADELPHIA HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  730 PM EDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN SOUTHEAST PENNSYLVANIA
 
   ...SOUTHERN CHESTER COUNTY
 
AT 630 PM WEATHER SERVICE RADAR SHOWED A SEVERE THUNDERSTORM OVER
EXTREME SOUTHEAST YORK COUNTY PENNSYLVANIA AND IN NEIGHBORING
HARFORD COUNTY MARYLAND.  THIS THUNDERSTORM WAS MOVING EAST AROUND
30 MPH.  THE THUNDERSTORM WILL MOVE EAST ALONG THE PENNSYLVANIA...
MARYLAND BORDER AND INTO CHESTER COUNTY BY 7 PM.
 
THIS THUNDERSTORM HAS PRODUCED STRONG WIND GUSTS AND MAY CONTAIN
LARGE HAIL.
 
THIS IS A DANGEROUS STORM.  IF YOU ARE IN THE WARNED AREA...PREPARE
FOR STRONG DAMAGING WINDS...LARGE HAIL...VERY HEAVY RAIN AND DEADLY
LIGHTNING.  SHOULD THE STORM APPROACH YOU\...SEEK IMMEDIATE SHELTER
INDOORS...BUT DO NOT STAND NEAR WINDOWS.  MOBILE HOMES ARE MOST
VULNERABLE TO HIGH WINDS AND SHOULD BE AVOIDED.

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 17, 7:24 PM EDTSevere Thunderstorm WarningPHIChester66 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 1992Every severe thunderstorm warning in 1992

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.