Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 1991

Severe Thunderstorm Warning 39, NWS Philadelphia/Mount Holly

July 23, 1991Bucks County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 23, 1991, 5:04 PM EDT for Bucks County, Pennsylvania. It was in force for 56 min.

The area

The counties it named.

The facts

Issued
Jul 23, 1991, 5:04 PM EDT (21:04 UTC)
Expired
Jul 23, 1991, 6:00 PM EDT
In force
56 min
Issued by
NWS Philadelphia/Mount Holly
Area
Whole counties

County Bucks County, PA

The nearest sounding before it

Atlantic City In, NJ (KACY), launched 12:00Z, 9.1 hours before the alert went out and 111 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 1991-07-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 835 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 1991-07-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 77 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
835 J/kg
Mixed-layer CIN
-143 J/kg
Mixed-layer LCL
1396 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
77 m²/s²
0-3 km storm-relative helicity
83 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 232104 RRA
SVRPHL
PAC017-232200-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHILADELPHIA PA
504 PM EDT TUE JUL 23 1991
 
THE NATIONAL WEATHER SERVICE IN PHILADELPHIA HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  600 PM EDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN SOUTHEAST PENNSYLVANIA
 
   ...BUCKS COUNTY
 
AT 500 PM...WEATHER SERVICE RADAR INDICATED A SEVERE THUNDERSTORM
JUST ENTERING UPPER BUCKS COUNTY. THIS THUNDERSTORM IS MOVING TO THE
SOUTHEAST AT 30 MILES AN HOUR.
 
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.
 
A TORNADO WATCH CONTINUES FOR SOUTHEASTERN
PENNSYLVANIA AND SOUTHERN NEW JERSEY UNTIL 900 PM EDT.  REMEMBER
SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE TORNADOES WITH
LITTLE OR NO ADVANCED WARNING.
 
JWH

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 1991Every severe thunderstorm warning in 1991

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.