Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 1992

Severe Thunderstorm Warning 48, NWS Philadelphia/Mount Holly

August 11, 1992Delaware County, Philadelphia County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 11, 1992, 3:19 PM EDT for Delaware County, Philadelphia County, Pennsylvania. It was in force for 41 min.

The area

The counties it named.

The facts

Issued
Aug 11, 1992, 3:19 PM EDT (19:19 UTC)
Expired
Aug 11, 1992, 4:00 PM EDT
In force
41 min
Issued by
NWS Philadelphia/Mount Holly
Area
Whole counties

Counties Delaware County, PA, Philadelphia County, PA

The nearest sounding before it

Atlantic City In, NJ (KACY), launched 12:00Z, 7.3 hours before the alert went out and 87 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 1992-08-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 757 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 1992-08-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 69 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
757 J/kg
Mixed-layer CIN
-53 J/kg
Mixed-layer LCL
1177 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
69 m²/s²
0-3 km storm-relative helicity
55 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KPHL 111920
SVRPHL
PAC045-101-112000-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHILADELPHIA PA
319 PM EDT TUE AUG 11 1992
 
THE NATIONAL WEATHER SERVICE IN PHILADELPHIA HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  400 PM EDT
FOR PEOPLE IN THE FOLLOWING LOCATIONS...
 
IN SOUTHEAST PENNSYLVANIA
 
   ...DELAWARE COUNTY...PHILADELPHIA COUNTY
 
AT 315 PM EDT NATIONAL WEATHER SERVICE RADAR SHOWED VERY STRONG
THUNDERSTORMS OVER DELAWARE AND PHILADELPHIA COUNTIES. THESE STORMS
WILL MOVE EAST SOUTHEAST AT 25 TO 30 MILES AN HOUR.
 
 
THIS IS A DANGEROUS STORM.  IF YOU ARE IN THE WARNED AREA...PREPARE
FOR STRONG DAMAGING WINDS...LARGE HAIL...VERY HlEAVY 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.
 
RPW

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 11, 1:24 PM EDTSevere Thunderstorm WarningPHIChester51 min
Aug 11, 1:58 PM EDTSevere Thunderstorm WarningPHIBucks, Montgomery62 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.