Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 1993

Severe Thunderstorm Warning 13, NWS Philadelphia/Mount Holly

June 9, 1993Montgomery County, Philadelphia County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jun 9, 1993, 7:43 PM EDT for Montgomery County, Philadelphia County, Pennsylvania. It was in force for 62 min.

The area

The counties it named.

The facts

Issued
Jun 9, 1993, 7:43 PM EDT (23:43 UTC)
Expired
Jun 9, 1993, 8:45 PM EDT
In force
62 min
Issued by
NWS Philadelphia/Mount Holly
Area
Whole counties

Counties Montgomery County, PA, Philadelphia County, PA

The nearest sounding before it

Atlantic City In, NJ (KACY), launched 12:00Z, 11.7 hours before the alert went out and 97 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 1993-06-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 366 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 1993-06-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 116 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
366 J/kg
Mixed-layer CIN
-215 J/kg
Mixed-layer LCL
971 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
116 m²/s²
0-3 km storm-relative helicity
136 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.6

Open this sounding in Storm Lab

The text

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

000 
WUUS1 KPHL 092346 RRA
SVRPHL
PAC091-101-100045-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHILADELPHIA PA
743 PM EDT WED JUN 9 1993
 
THE NATIONAL WEATHER SERVICE IN PHILADELPHIA HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  845 PM EDT
FOR PEOPLE IN THE FOLLOWING LOCATIONS...
 
IN SOUTHEAST PENNSYLVANIA
 
   ...EASTERN MONTGOMERY COUNTY...PHILADELPHIA COUNTY
 
AT 740 PM RADAR INDICATED A SEVERE THUNDERSTORM JUST EAST OF
NORRISTOWN. THIS STORM WAS MOVING EASTSOUTHEAST AROUND 40 MPH AND WILL
MOVE ACROSS EASTERN MONTGOMERY AND PHILADELPHIA COUNTY BY 840 PM EDT.
 
A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT FOR SOUTHEASTERN
PENNSYLVANIA UNTIL 10 PM EDT.
 
 
 
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.
 
 
 
TCB

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 9, 3:16 PM EDTSevere Thunderstorm WarningPHIBucks44 min
Jun 9, 4:13 PM EDTSevere Thunderstorm WarningPHIChester, Montgomery47 min
Jun 9, 4:30 PM EDTSevere Thunderstorm WarningPHIDelaware, Philadelphia45 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 1993Every severe thunderstorm warning in 1993

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.