Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 1988

Severe Thunderstorm Warning 29, NWS Philadelphia/Mount Holly

July 17, 1988Chester County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 17, 1988, 5:57 PM EDT for Chester County, Pennsylvania. It was in force for 48 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
Jul 17, 1988, 5:57 PM EDT (21:57 UTC)
Expired
Jul 17, 1988, 6:45 PM EDT
In force
48 min
Issued by
NWS Philadelphia/Mount Holly
Area
Whole counties

County Chester 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 17, 5:58 PM EDTHail 1Chester, 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, 10.0 hours before the alert went out and 122 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 1988-07-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1047 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 12:00Z on 1988-07-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 62 square meters per square second.1939Sfc1 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
1047 J/kg
Mixed-layer CIN
-143 J/kg
Mixed-layer LCL
900 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
62 m²/s²
0-3 km storm-relative helicity
86 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.9

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KPHL 172158 COR
SVRPHL
PAC029-172245-

BULLETIN - IMMEDIATE BROADCAST REQUESTED...CORRECTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHILADELPHIA PA
557 PM EDT SUN JUL 17 1988

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM
WARNING EFFECTIVE UNTIL 645 PM EDT FOR PEOPLE IN THE FOLLOWING
COUNTY

   IN THE SOUTHEAST PART OF PENNSYLVANIA
      CHESTER

AT 555 PM EDT RADAR INDICATED A SEVERE THUNDERSTORM NEAR
COATESVILLE...PENNSYLVANIA.  THIS THUNDERSTORM WAS MOVING TOWARD
THE SOUTHEAST AT 30 MILES AN HOUR.

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

 A SEVERE THUNDERSTORM WATCH CONTINUES FOR SOUTHEAST PENNSYVANIA.

 JSM

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

In the hours before

Special weather statement, Jul 17, 3:54 PM EDT, 2 hours 3 minutes before
ABPA-
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE ALLENTOWN PA
355 PM EDT SUN JULY 17 1988

...SEVERE THUNDERSTORM WATCH IN EFFECT UNTIL 8 PM EDT FOR EASTERN
    PENNSYLVANIA...

AT 355 PM EDT...NATIONAL WEATHER SERVICE RADAR INDICATED A LINE OF
HEAVY THUNDERSTORMS EXTENDING FROM SCRANTON SOUTHWESTWARD TO HAZLETON
AND CONTINUING SOUTHWESTWARD TO CENTRAL PENNSYLVANIA. THE LINE IS
MOVING SOUTHEASTWARD AT 30 MPH AND WILL MOVE ACROSS PIKE...MONROE...
CARBON AND SCHUYLKILL COUNTIES IN THE NEXT HOUR. THE HEAVIEST STORMS
ARE APPROAHING NORTHERN CARBON AND SCHUYLKILL COUNTIES. THE STORMS COULD
CONTAIN STRONG...GUSTY WINDS...HAIL...HEAVY DOWNPOURS AND DANGEROUS
LIGHTNING. PEOPLE LIVING IN CA(RBON AND SCHUYLKILL COUNTIES SHOULD SEEK
SHELTER WHEN THESE STORMS ARRIVE.

A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE FAVORABLE FOR SEVERE
THUNDERSTORMS TO DEVELOP IN AND CLOSE TO THE WATCH AREA.
 $$DOVICO
Special weather statement, Jul 17, 4:35 PM EDT, 1 hour 22 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PHILADELPHIA, PA
435 PM EDT SUN JUL 17 1988

...THUNDERSTORMS MOVING THROUGH SOUTHEAST PENNSYLVANIA...

AT 420 PM EDT AN AREA OF INTENSE THUNDERSTORMS WAS LOCATED FROM
THE LOWER SUSQUEHANNA VALLEY NORTHEAST THROUGH THE POCONOS. THE
STORMS ARE MOVING EAST SOUTHEAST AT 30 MILES AN HOUR AND WILL MOVE
INTO THE LANCASTER-READING-ALLENTOWN AREA AROUND 5 PM EDT. IF THE
STORMS MAINTAIN THEIR INTENSITY AND CURRENT MOVEMENT THEY WILL
BEGIN AFFECTING WESTERN PORTIONS OF THE PHILADELPHIA METROPOLITAN
AREA BY 7 PM EDT. THESE STORMS MAY BE ACCOMPANIED BY DANGEROUS
LIGHTNING...DAMAGING WINDS...AND TORRENTIAL DOWNPOURS.

A SEVERE THUNDERSTORM WATCH IS IN EFFECT UNTIL 8 PM EDT FOR MUCH OF
EASTERN PENNSYLVANIA. IN SOUTEAST PENNSYLVANIA THIS INCLUDES THE
COUNTIES OF CHESTER...MONTGOMERY...BUCKS...AND DELAWARE.

ADDITIONAL STATEMENTS WILL BE ISSUED AS THE THUNDERSTORMS APPROACH
THE PHILADELPHIA AREA.
Z
RPW
Special weather statement, Jul 17, 5:15 PM EDT, 42 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE ATLANTIC CITY, NEW JERSEY
515 PM EDT SUN JUL 17 1988

...A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR ALL OF NEW JERSEY
UNTIL 11 PM EDT...THIS INCLUDES THE COASTAL WATERS AND DELAWARE BAY...

PERSONS IN THE WATCH AREA SHOULD BE ON THE LOOKOUT FOR SEVERE
THUNDERSTORMS ACCOMPANIED BY DAMAGING WINDS...HAIL...HEAVY RAIN AND
FREQUENT LIGHTNING STRIKES. SEVERE THUNDERSTORM WARNINGS HAVE BEEN
ISSUED FOR SEVERAL COUNTIES IN PENNSYLVANIA ALREADY. WINDS HAVE GUSTED
TO 63 MPH AT READING PENNSYLVANIA.

AT 515 PM RADAR SHOWED A LINE OF THUNDERSTORMS FROM NORTHEAST
PENNSYLVANIA EXTENDING SOUTHWEST TO NORTHERN MARYLAND. THIS LINE
WILL APPROACH PARTS OF SOUTHWEST NEW JERSEY BETWEEN 7 AND 8 O'CLOCK
BUT THE TIME TO PREPARE FOR THE APPROACHING STORMS IS NOW.

IF YOU ARE A BOATER BEGIN THINKING OF RETURNING TO A SAFE PORT. SWIMERS
ENJOYING THE SURF AND SAND SHOULD ALSO CONSIDER CUTTING YOUR RECREATION
TIME. EBERWINE
Special weather statement, Jul 17, 5:23 PM EDT, 34 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE ATLANTIC CITY, NEW JERSEY
515 PM EDT SUN JUL 17 1988

...A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR ALL OF NEW JERSEY
UNTIL 11 PM EDT...THIS INCLUDES THE COASTAL WATERS AND DELAWARE BAY...

PERSONS IN THE WATCH AREA SHOULD BE ON THE LOOKOUT FOR SEVERE
THUNDERSTORMS ACCOMPANIED BY DAMAGING WINDS...HAIL...HEAVY RAIN AND
FREQUENT LIGHTNING STRIKES. SEVERE THUNDERSTORM WARNINGS HAVE BEEN
ISSUED FOR SEVERAL COUNTIES IN PENNSYLVANIA ALREADY. WINDS HAVE GUSTED
TO 63 MPH AT READING PENNSYLVANIA.

AT 515 PM RADAR SHOWED A LINE OF THUNDERSTORMS FROM NORTHEAST
PENNSYLVANIA EXTENDING SOUTHWEST TO NORTHERN MARYLAND. THIS LINE
WILL APPROACH PARTS OF SOUTHWEST NEW JERSEY BETWEEN 615 AMD 715 PM.
BUT THE TIME TO PREPARE FOR THE APPROACHING STORMS IS NOW.

IF YOU ARE A BOATER BEGIN THINKING OF RETURNING TO A SAFE PORT. SWIMERS
ENJOYING THE SURF AND SAND SHOULD ALSO CONSIDER CUTTING YOUR RECREATION
TIME.        EBERWINE
Special weather statement, Jul 17, 5:44 PM EDT, 13 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WILMINGTON DE
545 PM EDT SUN JUL 17 1988

 ...SEVERE THUNDERSTORM WATCH POSTED STATEWIDE UNTIL 11PM...

THE NATIONAL SEVERE STORMS FORECAST CENTER IN KANSAS CITY HAS
ISSUED A SEVERE THUNDERSTORM WATCH FOR THE STATE OF DELAWARE
AND OTHER PARTS OF THE MID-ATLANTIC REGION EFFECTIVE UNTIL
11 PM THIS EVENING.

A SEVERE THUNDERSTORM WATCH INDICATES THE POSSIBILITY THAT
THUNDERSTORMS IN THE AREA MAY BE ACCOMPANIED BY STRONG DAMAGING
WIND GUSTS...LARGE HAIL...HEAVY DOWNPOURS AND FREQUENT LIGHTNING.

RADAR PRESENTLY INDICATED A LINE OF STRONG STORMS STRETCHING FROM
SOUTHEASTERN PENNSYLVANIA ACROSS CENTRAL MARYLAND INTO NORTHERN
VIRGINIA.  THESE WERE MOVING EAST SOUTHEAST AT 25 MPH.

STORMS HAVE ALREADY PRODUCED WINDS AS HIGH AS 63 MPH IN EASTERN
 PENNSYLVANIA.

MOVE INDOORS TO A REINFORCED STRUCTURE IF A STORM APPROACHES.
STAY AWAY FROM WINDOWS.

REPORT THE OCCURRENCE OF SEVERE WEATHER TO LOCAL LAW ENFORCEMENT
AND ASK THEM TO RELAY THE MESSAGE TO THE NATIONAL WEATHER SERVICE.
YOU MAY ALSO CALL US DIRECTLY AT 328-7596 FOR SEVERE REPORTS ONLY.

HITCHENS
Special weather statement, Jul 17, 5:46 PM EDT, 11 minutes before
SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE ATLANTIC CITY, NEW JERSEY
542 PM EDT SUN JUL 17 1988

...A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR ALL OF NEW JERSEY
UNTIL 11 PM EDT...THIS INCLUDES THE COASTAL WATERS AND DELAWARE BAY...

PERSONS IN THE WATCH AREA SHOULD BE ON THE LOOKOUT FOR SEVERE
THUNDERSTORMS ACCOMPANIED BY DAMAGING WINDS...HAIL...HEAVY RAIN AND
FREQUENT LIGHTNING STRIKES. SEVERE THUNDERSTORM WARNINGS HAVE BEEN
ISSUED FOR SEVERAL COUNTIES IN PENNSYLVANIA ALREADY. WINDS HAVE GUSTED
TO 63 MPH AT READING PENNSYLVANIA.

AT 535 PM RADAR SHOWED A LINE OF STRONG THUNDERSTORMS FROM FROM CENTRAL WARREN
COUNTY NORTHWEST NEW JERSEY TO BOYERTOWN AND THEN TO PARKESBURG SOUTHEAST
PENNSYLVANIA. THIS LINE WAS MOVING EASTSOUTHEAST AT 20 MILES AN HOUR...WHILE THESTORMS WERE MOVING EASTSOUTHEAST AT 30 MILES AN HOUR.

OTHER SHOWERS AND THUNDERSTORMS...SOME WITH HEAVY TO VERY HEAVY RAIN...WERE
SCATTERED FROM EXTREM NORTHERN VIRGINIA ACROSS NORTH CENTRAL MARYLAND INTO THE
LOWER SUSQUEHANNA VALLEY OF PENNSYLVANIA...SOUTHEAST EASTERN AND NORTHEAST

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 17, 5:07 PM EDTSevere Thunderstorm WarningPHIBucks, Montgomery53 min
Jul 17, 5:11 PM EDTSevere Thunderstorm WarningPHIChester49 min
Jul 17, 6:18 PM EDTSevere Thunderstorm WarningPHIPhiladelphia27 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.