Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 1994

Severe Thunderstorm Warning 91, NWS Philadelphia/Mount Holly

August 13, 1994Bucks County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 13, 1994, 4:35 PM EDT for Bucks County, Pennsylvania. It was in force for 40 min.

The area

The counties it named.

The facts

Issued
Aug 13, 1994, 4:35 PM EDT (20:35 UTC)
Expired
Aug 13, 1994, 5:15 PM EDT
In force
40 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, 8.6 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 1994-08-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1816 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 1994-08-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 111 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
1816 J/kg
Mixed-layer CIN
-74 J/kg
Mixed-layer LCL
906 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
111 m²/s²
0-3 km storm-relative helicity
121 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 132041 RRA
SVRPHL
PAC017-132115-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHILADELPHIA/MOUNT HOLLY NJ
435 PM EDT SAT AUG 13 1994
 
THE NATIONAL WEATHER SERVICE IN PHILADELPHIA/MOUNT HOLLY HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  515 PM EDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN SOUTHEAST PENNSYLVANIA
 
   ...BUCKS COUNTY
 
A STRONG THUNDERSTORM WAS DETECTED ALONG THE MONTGOMERY/BUCKS COUNTY
BORDER IN THE VICINITY OF PERKASIE. THE STORM WAS MOVING EAST 30 MPH.
 
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 SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT FOR MOST OF EASTERN
PENNSYLVANIA UNTIL 8 PM EDT
 
 

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 13, 3:59 PM EDTSevere Thunderstorm WarningPHIBerks, Montgomery46 min
Aug 13, 5:21 PM EDTSevere Thunderstorm WarningPHIChester, Montgomery54 min
Aug 13, 6:22 PM EDTSevere Thunderstorm WarningPHIBucks, Montgomery, Philadelphia33 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 1994Every severe thunderstorm warning in 1994

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.