Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 1996

Severe Thunderstorm Warning 33, NWS Philadelphia/Mount Holly

June 4, 1996Chester County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jun 4, 1996, 10:21 PM EDT for Chester County, Pennsylvania. It was in force for 39 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
Jun 4, 1996, 10:21 PM EDT (02:21 UTC)
Expired
Jun 4, 1996, 11:00 PM EDT
In force
39 min
Issued by
NWS Philadelphia/Mount Holly
Area
Whole counties

County Chester County, PA

The radar

The Philadelphia radar (KDIX), 114 km from the middle of the area, began a volume at 02:23 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

TimeReportWhereRemark
Jun 4, 10:35 PM EDTThunderstorm WindPhoenixville, 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.

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 00:00Z, 2.4 hours before the alert went out and 182 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, Washington/Dulle, VA at 00:00Z on 1996-06-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1358 joules per kilogram.LCLEL10008507005003002001001 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, Washington/Dulle, VA at 00:00Z on 1996-06-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 137 square meters per square second.1939587897Sfc1 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
1358 J/kg
Mixed-layer CIN
-8 J/kg
Mixed-layer LCL
1174 m above ground
0-6 km bulk shear
51 kt
0-1 km storm-relative helicity
137 m²/s²
0-3 km storm-relative helicity
121 m²/s²
Significant tornado parameter
0.8
Supercell composite
3.9

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KPHL 050223
SVRPHL
PAC029-050300-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHILADELPHIA/MOUNT HOLLY NJ
1021 PM EDT TUE JUN 4 1996
 
THE NATIONAL WEATHER SERVICE IN PHILADELPHIA/MOUNT HOLLY HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 1100 PM EDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN  PENNSYLVANIA
 
   ...EASTERN CHESTER COUNTY
 
NATIONAL WEATHER SERVICE DOPPLER RADAR SHOWED A DEVELOPING SEVERE
THUNDERSTORM OVER CENTRAL CHESTER COUNTY NEAR DOWNINGTOWN. MOVEMENT
WAS NORTHEAST AT 30 MILES AN HOUR AND SHOULD PASS CLOSE TO EXTON AND
GLEN ROCK ALONG U.S. ROUTE 30.
 
THIS IS A DANGEROUS STORM.  PREPARE FOR STRONG DAMAGING WINDS...
LARGE HAIL...HEAVY RAINS AND DEADLY LIGHTNING.  SHOULD THE STORM
APPROACH MOVE INSIDE QUICKLY. DO NOT STAND NEAR WINDOWS.  MOBILE
HOMES ARE MOST VULNERABLE TO HIGH WINDS AND SHOULD BE AVOIDED.
 
TFG

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 1996Every severe thunderstorm warning in 1996

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; radar from the NEXRAD Level II archive.