Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 1986

Severe Thunderstorm Warning 7, NWS Philadelphia/Mount Holly

August 2, 1986Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 2, 1986, 3:04 PM EDT for Montgomery County, Pennsylvania. It was in force for 41 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
Aug 2, 1986, 3:04 PM EDT (19:04 UTC)
Expired
Aug 2, 1986, 3:45 PM EDT
In force
41 min
Issued by
NWS Philadelphia/Mount Holly
Area
Whole counties

County Montgomery 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
Aug 2, 3:15 PM EDTThunderstorm Wind 0Montgomery, 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 12:00Z, 7.1 hours before the alert went out and 112 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 1986-08-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 548 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 1986-08-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 31 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
548 J/kg
Mixed-layer CIN
-45 J/kg
Mixed-layer LCL
1078 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
31 m²/s²
0-3 km storm-relative helicity
59 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.4

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KPHL 021921
SVRPHL
PAC091-021945-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHILADELPHIA PA
304 PM EDT SAT AUG 2 1986

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM
WARNING EFFECTIVE UNTIL 345 PM EDT FOR PEOPLE IN THE FOLLOWING
COUNTY OF

SOUTHEAST PENNSYLVANIA...WESTERN MONTGOMERY

AT 3 PM EDT  RADAR INDICATED A SEVERE THUNDERSTORM IN EXTREME NORTHERN
CHESTER COUNTY MOVING NORTHEAST AROUND 30 MILES AN HOUR.
 THIS IS A DANGEROUS STORM AND PEOPLE IN THE WARNED AREA SHOULD
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.
 ACS

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.