Alert archive / Pennsylvania / Flash Flood Warnings in 1987

Flash Flood Warning 7, NWS State College, PA

September 17, 1987Cumberland County, Pennsylvania

NWS State College, PA issued this flash flood warning at Sep 17, 1987, 9:04 PM EDT for Cumberland County, Pennsylvania. It was in force for 3 hr.

The area

The counties it named.

The facts

Issued
Sep 17, 1987, 9:04 PM EDT (01:04 UTC)
Expired
Sep 18, 1987, 12:00 AM EDT
In force
3 hr
Issued by
NWS State College, PA
Area
Whole counties

County Cumberland 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

Washington/Dulle, VA (KIAD), launched 00:00Z, 1.1 hours before the alert went out and 135 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, Washington/Dulle, VA at 00:00Z on 1987-09-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1181 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, Washington/Dulle, VA at 00:00Z on 1987-09-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 90 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
1181 J/kg
Mixed-layer CIN
-62 J/kg
Mixed-layer LCL
1046 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
90 m²/s²
0-3 km storm-relative helicity
120 m²/s²
Significant tornado parameter
0.3
Supercell composite
2.8

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KHAR 180105
FFWHAR
PAC041-180400-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE HARRISBURG PA
904 PM EDT THU SEP 17 1987
 
THE NATIONAL WEATHER SERVICE HAS ISSUED A FLASH FLOOD WARNING
EFFECTIVE UNTIL 1200 AM EDT FOR THE FOLLOWING COUNTY OF
 
SOUTH CENTRAL PENNSYLVANIA... CUMBERLAND
                                                                         
AT 850 PM EDT A SEVERE THUNDERSTORM WAS LOCATED OVER CUMBERLAND COUNTY 
PRODUCING VERY HEAVY RAIN. COUNTY CONTROL PERSONNEL HAVE RECEIVED 
SEVERAL REPORTS OF FLOODED UNDERPASSES.  
 
A FLASH FLOOD WARNING MEANS FLOODING IN OCCURRING OR IS IMMINENT.
 
IF YOU GET ANY INDICjATION THAT FLOOD WATERS ARE APPROACHING MOVE TO
HIGHER GROUND IMMEDIATELY.  DO NOT DRIVE THROUGH FLOOD WATERS.
DO NOT WADE THROUGH FLOOD WATERS.
 
MF

What forecasters said that day

The local office's own words before this flash flood 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, Sep 17, 4:06 PM EDT, 4 hours 58 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HARRISBURG PA.
400 PM EDT  THU  SEP 17 1987

...VERY HEAVY THUNDERSTORMS MOVING TOWARDS THE MIDDLE AND LOWER
SUSQUEHANNA VALLEY...

THE HARRIBURG WEATHER RADAR AT 345 PM EDT WAS OBSERVING VERY HEAVY
THUNDERSTORMS THAT EXTENDED FROM CENTRE COUNTY SOUTH INTO HUNTINGDON
AND MIFFLIN COUNTIES.

THIS AREA OF THUNDERSTORMS HAS MOVING EAST AT 25 TO 30 MPH AND WILL BE
INTO THE WESTERN PORTION OF THE MIDDLE AND LOWER SUSQUEHANNA VALLEY BY
430 PM EDT. HEAVY RAINS...FREQUENT LIGHTNING AND GUSTY WINDS
HAVE BEEN REPORTED WITH THESE STORMS.

POEPLE IN THE ABOVE LISTED COUNTIES SHOULD BE ALERT TO RAPIDLY
CHANGING WEATHER CONDITIONS UNTIL 500 PM EDT.

WSO HAR NEFF
Special weather statement, Sep 17, 5:10 PM EDT, 3 hours 54 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HARRISBURG PA.
505 PM EDT  THU  SEP 17 1987

...VERY HEAVY THUNDERSTORMS IN MIDDLE AND NORTHERN PORTION OF THE
LOWER SUSQUEHANNA VALLEY...

THE HARRIBURG WEATHER RADAR AT 455 PM EDT WAS OBSERVING VERY HEAVY
THUNDERSTORMS THAT EXTENDED FROM MONTOUR AND NORTHUMBERLAND COUNTIES
SOUTH INTO DAUPHIN COUNTY.

A SECOND AREA OF VERY HEAVY THUNDERSTORM WAS LOCATED IN NORTHWESTERN
HUNTINGDON AND CENTRAL PORTION OF CENTRE COUNTY.

RAINFALL AMOUNTS FROM THESE THUNDERSTORMS HAVE THE POTENTIAL OF
PRODUCING FLOODING IN LOW LYING AREAS.

THE STORMS CONTINUE TO MOVE EAST AT 25 TO 35 MPH.

WSO HAR NEFF
Special weather statement, Sep 17, 5:56 PM EDT, 3 hours 8 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HARRISBURG PA.
550 PM EDT THU SEP 17 1987

...VERY HEAVY THUNDERSTORMS CONTINUE MOVING RADIPLY EAST FROM THE
WESTERN MOUNTAINS THROUGH THE SUSQUEHANNA VALLEY...

AT 540 PM EDT THE NATIONAL WEATHER SERVICE RADAR WAS OBSERVING TWO
CLUSTERS OF VERY HEAVY THUNDERSTORMS.  THE FIRST CLUSTER WAS
LOCATED FROM COLUMBIA COUNTY SOUTH INTO SCHUYLKILL...LEBANON AND
DAUPHIN COUNTIES.

A SECOND CLUSTER OF VERY HEAVY THUNDERSTORMS WAS LOCATED IN MIFFLIN
AND HUNTINGDON COUNTIES.

AS THESE THUNDERSTORMS MOVE EAST AT 25 TO 30 MPH...THEY WILL BE
ACCOMPANIED BY BRIEF HEAVY DOWNPOURS...POSSIBLY CAUSING FLOODING IN
AREAS OF POOR DRAINAGE...GUSTY SURFACE WINDS AND POSSIBLY SMALL HAIL.

RESIDENTS SHOULD BE ALERT FOR RAPIDLY CHANGING WEATHER CONDITIONS
UNTIL 700 PM EDT.
WSO HAR FITZSIMMONS
Special weather statement, Sep 17, 6:59 PM EDT, 2 hours 5 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HARRISBURG PA.
655 PM EDT THU SEP 17 1987

...VERY HEAVY THUNDERSTORMS OCCURRING OVER THE SOUTH CENTRAL MOUNTAINS
AND SOUTH CENTRAL PENNSYLVANIA...

AT 650 PM EDT THE NATIONAL WEATHER SERVICE RADAR WAS INDICATING AN AREA
OF VERY HEAVY THUNDERSTORMS EXTENDING FROM CENTER COUNTY SOUTH INTO
HUNTINGDON COUNTY.  THE STRONGEST STORMS WERE LOCATED JUST EAST OF
RAYSTOWN LAKE AND BETWEEN BELLEVILLE AND LEWISTON IN MIFFLIN COUNTY.

AS THESE THUNDERSTORMS CONTINUE TO THE EAST AT 25 TO 30 MPH...THEY
WILL BE ACCOMPANIED BY BRIEF HEAVY DOWNPOURS POSSIBLY CAUSING FLOODING
IN AREAS OF POOR DRAINAGE...GUSTY SURFACE WINDS AND FREQUENT LIGHTNING.

RESIDENTS IN THESE COUNTIES AND IN THE COUNTIES OF UNION...SYNDER...
JUNIATA AND PERRY COUNTIES CAN EXPECT RAPIDLY CHANGING WEATHER CONDITION
UNTIL 800 PM EDT

WSO HAR FITZSIMMONS
Special weather statement, Sep 17, 7:04 PM EDT, 2 hours before
SPECIAL WEATHER STATEMENT...CORRECTION
NATIONAL WEATHER SERVICE HARRISBURG PA.
655 PM EDT THU SEP 17 1987

...VERY HEAVY THUNDERSTORMS OCCURRING OVER THE SOUTH CENTRAL MOUNTAINS
AND SOUTH CENTRAL PENNSYLVANIA...

AT 650 PM EDT THE NATIONAL WEATHER SERVICE RADAR WAS INDICATING AN AREA
OF VERY HEAVY THUNDERSTORMS EXTENDING FROM CENTER COUNTY SOUTH INTO
HUNTINGDON COUNTY.  THE STRONGEST STORMS WERE LOCATED JUST EAST OF
RAYSTOWN LAKE AND BETWEEN BELLEVILLE AND LEWISTON IN MIFFLIN COUNTY.

AS THESE THUNDERSTORMS CONTINUE TO THE EAST AT 25 TO 30 MPH...THEY
WILL BE ACCOMPANIED BY BRIEF HEAVY DOWNPOURS POSSIBLY CAUSING FLOODING
IN AREAS OF POOR DRAINAGE...GUSTY SURFACE WINDS AND FREQUENT LIGHTNING.

RESIDENTS IN THESE COUNTIES AND IN THE COUNTIES OF UNION...SYNDER...
JUNIATA AND PERRY CAN EXPECT RAPIDLY CHANGING WEATHER CONDITION
UNTIL 800 PM EDT.

WSO HAR FITZSIMMONS
Special weather statement, Sep 17, 8:19 PM EDT, 45 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HARRISBURG PA.
810 PM EDT THU SEP 17 1987

...CLUSTER OF INTENSE THUNDERSTORMS MOVING ACROSS CUMBERLAND COUNTY...

AT 815 PM EDT THE NATIONAL WEATHER SERVICE RADAR WAS OBSERVING AN
INTENSE CLUSTER OF THUNDERSTORMS MOVING ACROSS NORTHERN CUMBERLAND COUNTY.
SPOTTERS IN THE NEWVILLE AREA HAVE REPORTED PEA SIZE HAIL REDUCING
VISIBILITIES TO NEAR ZERO.

THIS STORM WILL CONTINUE MOVING EAST AT 25 TO 30 MPH AND WILL PRODUCE
VERY HEAVY RAIN POSSIBLY CAUSING FLOODING IN AREAS OF POOR DRAINAGE...
GUSTY SURFACE WINDS AND HAIL.

RESIDENTS IN CUMBERLAND COUNTY SHOULD BE ON THE LOOKOUT FOR THREATENING
WEATHER CONDITIONS UNTIL 900 PM EDT.

END
WSO HAR 9FITZSIMMONS

The office that day

Everything else NWS State College, PA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 17, 8:54 PM EDTSevere Thunderstorm WarningCTPCumberland56 min
Sep 17, 11:23 PM EDTSevere Thunderstorm WarningCTPAdams57 min
Sep 18, 5:26 PM EDTSevere Thunderstorm WarningCTPLancaster64 min

Nearby

Flash Flood Warnings in Pennsylvania, 1987Every flash flood warning in 1987

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.