Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 1986

Severe Thunderstorm Warning 4, NWS Philadelphia/Mount Holly

July 19, 1986Delaware County, Montgomery County, Philadelphia County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 19, 1986, 1:58 AM EDT for Delaware County, Montgomery County, Philadelphia County, Pennsylvania. It was in force for 32 min. 3 reports 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
Jul 19, 1986, 1:58 AM EDT (05:58 UTC)
Expired
Jul 19, 1986, 2:30 AM EDT
In force
32 min
Issued by
NWS Philadelphia/Mount Holly
Area
Whole counties

Counties Delaware County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.

What was reported inside it

TimeReportWhereRemark
Jul 19, 2:05 AM EDTThunderstorm Wind 0Montgomery, PA
Jul 19, 2:10 AM EDTThunderstorm Wind 0Delaware, PA
Jul 19, 2:15 AM EDTHail 0.75Philadelphia, 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. Storm Data before 1996 records only tornadoes, thunderstorm wind and hail.

The nearest sounding before it

Atlantic City In, NJ (KACY), launched 00:00Z, 6.0 hours before the alert went out and 95 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 00:00Z on 1986-07-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 684 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Atlantic City In, NJ at 00:00Z on 1986-07-19The 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
684 J/kg
Mixed-layer CIN
-65 J/kg
Mixed-layer LCL
958 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
100 m²/s²
0-3 km storm-relative helicity
145 m²/s²
Significant tornado parameter
0.4
Supercell composite
2.8

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KPHL 190558
SVRPHL
PAC101-045-091-190630-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHILADELPHIA PA
158 AM EDT SAT JUL 19 1986

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM 
WARNING EFFECTIVE UNTIL 230 AM EDT FOR PEOPLE IN THE FOLLOWING 
COUNTIES OF

SOUTHEAST PENNSYLVANIA...PHILADELPHIA...EASTERN DELAWARE AND 
 SOUTHERN MONTGOMERY

AT 155 AM EDT RADAR INDICATED A HEAVY THUNDERSTORM OVER WESTERN
PORTION OF PHILADELPHIA COUNTY AND A TRAINED WEATHER SPOTTER
REPORTED 1 INCH HAIL OVER KING OF PRUSSIA PA.

 THE STORM WAS MOVING TOWARD THE SOUTH AT 30 MILES AN HOUR.

 THIS IS A DANGEROUS STORM AND PEOPLE IN THE WARNED AREA SHOULDC
PREPARE FOR STRONG DAMAGING WINDS..LARGE HAIL..VERY HEAVY RAIN AND
LIGHTNING. SHOULD THE STORM APPROACH YOU..SEEK IMMEDIATE SHELTER.
MOBILE TRAILERS ARE MOST VULNERABLE TO HIGH WINDS AND SHOULD BE
AVOIDED.

 KWH

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 1986Every severe thunderstorm warning in 1986

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.