Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 1988

Severe Thunderstorm Warning 4, NWS Philadelphia/Mount Holly

May 10, 1988Delaware County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at May 10, 1988, 9:19 PM EDT for Delaware County, Pennsylvania. It was in force for 41 min.

The area

The counties it named.

The facts

Issued
May 10, 1988, 9:19 PM EDT (01:19 UTC)
Expired
May 10, 1988, 10:00 PM EDT
In force
41 min
Issued by
NWS Philadelphia/Mount Holly
Area
Whole counties

County Delaware County, PA

The radar

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

The nearest sounding before it

Atlantic City In, NJ (KACY), launched 00:00Z, 1.3 hours before the alert went out and 93 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 1988-05-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 468 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 00:00Z on 1988-05-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 35 square meters per square second.19395878Sfc1 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
468 J/kg
Mixed-layer CIN
-88 J/kg
Mixed-layer LCL
1200 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
35 m²/s²
0-3 km storm-relative helicity
61 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 110120
SVRPHL
PAC045-110200-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHILADELPHIA PA
919 PM EDT TUE MAY 10 1988
 
THE NATIONAL WEATHER SERVICE IN PHILADELPHIA HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 1000 PM EDT
FOR PEOPLE IN THE FOLLOWING COUNTY...
 
IN SOUTHEAST PENNSYLVANIA
          ...DELAWARE
 
STRONG THUNDERSTORMS MOVING EAST THROUGH CHESTER COUNTY AT
915 PM WILL MOVE INWTO DELAWARE COUNTY BY 930 PM. HAIL UP TO 1 INCH
IN DIAMETER AND BRIEFLY HEAVY RAINS HAVE BEEN ACCOMPANYING THESE
THUNDERSTORMS.

The office that day

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

IssuedProductOfficeCountiesLasted
May 10, 8:19 PM EDTSevere Thunderstorm WarningPHIChester, Montgomery41 min
May 10, 9:00 PM EDTSevere Thunderstorm WarningPHIChester, Montgomery45 min
May 10, 9:52 PM EDTSevere Thunderstorm WarningPHIBucks, Chester, Montgomery53 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 1988Every severe thunderstorm warning in 1988

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.