Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 1992

Severe Thunderstorm Warning 43, NWS Philadelphia/Mount Holly

July 31, 1992Chester County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 31, 1992, 4:43 PM EDT for Chester County, Pennsylvania. It was in force for 77 min.

The area

The counties it named.

The facts

Issued
Jul 31, 1992, 4:43 PM EDT (20:43 UTC)
Expired
Jul 31, 1992, 6:00 PM EDT
In force
77 min
Issued by
NWS Philadelphia/Mount Holly
Area
Whole counties

County Chester County, PA

The nearest sounding before it

Atlantic City In, NJ (KACY), launched 12:00Z, 8.7 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 1992-07-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 798 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 1992-07-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 100 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
798 J/kg
Mixed-layer CIN
-29 J/kg
Mixed-layer LCL
721 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
100 m²/s²
0-3 km storm-relative helicity
137 m²/s²
Significant tornado parameter
0.4
Supercell composite
2.5

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KPHL 312044
SVRPHL
PAC029-312200-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHILADELPHIA PA
443 PM EDT FRI JUL 31 1992
 
THE NATIONAL WEATHER SERVICE IN PHILADELPHIA HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  543 PM EDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN SOUTHEAST PENNSYLVANIA
 
   ...CHESTER COUNTY
 
AT 435 PM RADARS SHOWED A POTENTIALLY SEVERE THUNDERSTORM APPROACHING
THE EXTREME SOUTHWEST PART OF THE COUNTY IN THE VICINITY OF WEST
NOTINGHAM TOWNSHIP ALONG ROUTE 1.
 
THIS STORM WAS MOVING NORTHEAST 30 TO 35 MPH AND MAY BE ACCOMPANIED BY
DAMAGING WINDS AND HAIL AS IT MOVES NORTHEAST ACROSS THE ENTIRE COUNTY.
 
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 MDOST
VULNERABLE TO HIGH WINDS AND SHOULD BE AVOIDED.
 
EBERWINE

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 31, 5:46 PM EDTSevere Thunderstorm WarningPHIPhiladelphia59 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; the sounding from the Mesonet's radiosonde archive.