Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 1988

Severe Thunderstorm Warning 2, NWS Philadelphia/Mount Holly

May 10, 1988Chester County, Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at May 10, 1988, 8:19 PM EDT for Chester County, Montgomery County, Pennsylvania. It was in force for 41 min. 2 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: May 10, 1988, 8:19 PM EDT (00:19 UTC)
Expired: May 10, 1988, 9:00 PM EDT
In force: 41 min
Issued by: NWS Philadelphia/Mount Holly
Area: Whole counties

Counties Chester County, PA, 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

Time	Report	Where	Remark
May 10, 8:45 PM EDT	Hail 0.75	Chester, PA
May 10, 9:02 PM EDT	Hail 0.75	Chester, 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, 0.3 hours before the alert went out and 115 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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 110020
SVRPHL
PAC029-091-110100-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHILADELPHIA PA
819 PM EDT TUE MAY 10 1988
 
THE NATIONAL WEATHER SERVICE IN PHILADELPHIA HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  900 PM EDT
FOR PEOPLE IN THE FOLLOWING COUNTIES...
 
IN SOUTHEAST PENNSYLVANIA
          ...CHESTER...MONTGOMERY
 
AT 815 PM A LINE OF STRONG THUNDERSTORMS EXTENDED FROM HAMBURG
TO WOMELSDORF TO LANCASTER TO YORK IN PENNSYLVANIA. THIS LINE WAS
MOVING EAST AROUND 20 MPH AND WILL MOVE THROUGH CHESTER AND MONTGOMERY
COUNTIES IN PENNSYLVANIA BETWEEN NOW AND 9 PM.
 
     ANOTHER STRONG THUNDERSTORM WAS MOVING FROM NORTHERN CHESTER
COUNTY INTO WESTERN MONTGOMERY COUNTY.
 
THIS IS A DANGEROUS STORM.  IF YOU ARE IN THE WARNED AREA...BE
PREPARED FOR STRONG DAMAGING WINDS...LARGE HAIL...VERY HEAVY RAIN
AND DANGEROUS LIGHTNING.  SHOULD THE STORM APPROACH YOU...SEEK
IMMEDIATE SHELTER.  MOBILE HOMES ARE MOST VULNERABLE TO HIGH WINDS
AND SHOULD BE AVOIDED.

The office that day

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

Issued	Product	Office	Counties	Lasted
May 10, 9:00 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Montgomery	45 min
May 10, 9:19 PM EDT	Severe Thunderstorm Warning	PHI	Delaware	41 min
May 10, 9:52 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Chester, Montgomery	53 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 1988 Every 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.