Alert archive / Pennsylvania / Flash Flood Warnings in 1987

Flash Flood Warning 2, NWS State College, PA

September 8, 1987Lancaster County, Pennsylvania

NWS State College, PA issued this flash flood warning at Sep 8, 1987, 9:30 PM EDT for Lancaster County, Pennsylvania. It was in force for 3 hr.

The area

The counties it named.

The facts

Issued
Sep 8, 1987, 9:30 PM EDT (01:30 UTC)
Expired
Sep 9, 1987, 12:00 AM EDT
In force
3 hr
Issued by
NWS State College, PA
Area
Whole counties

County Lancaster 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, 1.5 hours before the alert went out and 157 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 1987-09-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 171 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, Washington/Dulle, VA at 00:00Z on 1987-09-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -70 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
171 J/kg
Mixed-layer CIN
-61 J/kg
Mixed-layer LCL
574 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
-70 m²/s²
0-3 km storm-relative helicity
-38 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.2

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

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 8, 5:48 PM EDT, 3 hours 42 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HARRISBURG PA.
545 PM EDT    TUE  SEP 8 1987

      ...SOME FLOODING OCCURRING IN LANCASTER COUNTY...

PROLONGED HEAVY RAINS HAVE CAUSED SOME FLOODING OF STREETS AND
HIGHWAYS IN LANCASTER COUNTY. REPORT FROM CO OP OBSERVER INDICATES
THAT QUITE A FEW SMALL CREEKS ARE GOING OVER THEIR BANKS.

RADAR INDICATED SOME QUITE HEAVY RAINS MOVING ACROSS LANCASTER COUNTY
AND THIS HEAVY RAIN SHOULD PERSIST UNTIL AT LEAST 7 PM THIS EVENING.

RESIDENTS OF LANCASTER COUNTY SHOULD BE ALERT FOR HIGHWAY AND SMALL
STREAM FLOODING AND IF YOU LIVE NEAR A SMALL STREAM BE PREPARED TO
MOVE TO HIGHER GROUND SHOULD FLOODING BEGIN. ALSO DO NOT DRIVE THROUGH
FLOODED HIGHWAYS...IT COULD BE YOUR LAST TRIP.

END
WSO HAR CURLL
Special weather statement, Sep 8, 6:07 PM EDT, 3 hours 23 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HARRISBURG PA.
 600 PM EDT    TUE  SEP 8 1987

 ...VERY HEAVY RAINS CONTINUE ACROSS PORTIONS OF LANCASTER COUNTY...

AT 600 PM RADAR WAS SHOWING A BAND OF HEAVY RAIN THAT COVERED MUCH
OF THE EASTERN THIRD OF LANCASTER COUNTY. THIS HEAVY RAIN WAS MOVING
TO THE NORTHEAST AT AROUND 25 MILES AN HOUR. SMALL STREAMS AND FARM
CREEKS ARE GOING OUT OF THEIR BANKS THROUGHOUT THE COUNTY AND RESIDENTS
OF THE COUNTY THAT LIVE NEAR SMALL CREEKS AND STREAMS SHOULD BE PREPARED
TO MOVE TO HIGHER GROUND SHOULD FLOODING BEGIN.

RAINFALL IN SOME AREAS OF THE COUNTY HAS BEEN IN EXCESS OF 51/2 INCHES.

SOME RAIN FALL AMOUNTS FORM THE COUNTY INCLUDE....
LANCASTER...5.12 INCHES
LEOLA...... 5.00

MANOR TWP.... 5.50 INCHES
NEW HOLAND.....4.50
CONESTOGA......5.60

HEAVY RAIN FALLING ACROSS LANCASTER COUNTY SHOULD MOVE OUT OF THE AREA
BY AROUND 730 PM THIS EVENING.

CURLL WSO HARRISBURG
Special weather statement, Sep 8, 6:08 PM EDT, 3 hours 22 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HARRISBURG PA.
 600 PM EDT    TUE  SEP 8 1987

 ...VERY HEAVY RAINS CONTINUE ACROSS PORTIONS OF LANCASTER COUNTY...

AT 600 PM RADAR WAS SHOWING A BAND OF HEAVY RAIN THAT COVERED MUCH
OF THE EASTERN THIRD OF LANCASTER COUNTY. THIS HEAVY RAIN WAS MOVING
TO THE NORTHEAST AT AROUND 25 MILES AN HOUR. SMALL STREAMS AND FARM
CREEKS ARE GOING OUT OF THEIR BANKS THROUGHOUT THE COUNTY AND RESIDENTS
OF THE COUNTY THAT LIVE NEAR SMALL CREEKS AND STREAMS SHOULD BE PREPARED
TO MOVE TO HIGHER GROUND SHOULD FLOODING BEGIN.

RAINFALL IN SOME AREAS OF THE COUNTY HAS BEEN IN EXCESS OF 51/2 INCHES.

SOME RAIN FALL AMOUNTS FORM THE COUNTY INCLUDE....
LANCASTER...5.12 INCHES
LEOLA...... 5.00

MANOR TWP.... 5.50 INCHES
NEW HOLAND.....4.50
CONESTOGA......5.60

HEAVY RAIN FALLING ACROSS LANCASTER COUNTY SHOULD MOVE OUT OF THE AREA
BY AROUND 730 PM THIS EVENING.

CURLL WSO HARRISBURG
Special weather statement, Sep 8, 7:31 PM EDT, 1 hour 59 minutes before
SPECIAL WEATHER STATEMANT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE HARRISBURG PA
730 PM EDT TUE SEP 8 1987

....... FLASH FLOOD WARNING REMAINS IN EFFECT FOR LANCASTER COUNTY
        UNTIL 10 PM THIS MONDAY EVENING.....

AT 725 PM RADAR WAS SHOWING SOME PATCHES OF VERY RAIN AND POSSIBLE HEAVY
THUNDERSTORMS ACROSS PORTIONS OF EASTERN LANCASTER COUNTY AND ALONG THE
LANCASTER...CHESTER COUNTY LINE.  ADDITIONAL HEAVY RAINS WERE SCATTERED
ACROSS BERKS COUNTY NEAR READING.

THIS HEAVY RAIN WAS PART OF A LARGER AREA OF RAIN THAT COVERED MUCH OF
EXTREME EASTERN PENNSYLVANIA. THE BACK OR TRAILING EDGE OF RAIN AREA EXTENDED
FROM NEAR MONTROSE...IN SUSQUEHANNA COUNTY... SOUTH TO NEAR LANCASTER. RAIN

WAS MOVING TO THE NORTHEAST AT AROUND 25 MPH AND ALL THE HEAVY RAIN SHOULD BE
OUT OF LANCASTER COUNTY BY 830 PM THIS MONDAY EVENING.
CURLL WSO HARRISBURG
Special weather statement, Sep 8, 8:14 PM EDT, 1 hour 16 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HARRISBURG PA.
815 PM EDT    TUE  SEP 8 1987

 ...FLASH FLOOD WARNING REMAINS IN EFFECT FOR LANCASTER COUNTY
    UNTIL 10 PM THIS MONDAY EVENING...

AT 8 PM RADAR WAS SHOWING A FEW PATCHES OF HEAVY RAIN IN EXTREME
EASTERN LANCASTER COUNTY WITH SOME LIGHTER RAIN IN CENTRAL AREAS OF
THE COUNTY. THE RAIN WAS MOVING TO THE NORTHEAST AT AROUND 25 MPH
AND IF THIS SPEED AND DIRECTION CONTINUES..THAN ALL THE RAIN SHOULD
BE OUT OF THE COUNTY BY 930 THIS EVENING.

MR BILL JOHNSON ...LANCASTER COUNTY EOC...REPORTED TO THIS OFFICE
THAT JUST ABOUT ALL STREAMS AND CREEKS IN THE COUNTY WERE OUT OF
THEIR BANKS AND THE CONESTOGA CREEK AT AROUND 8PM WAS 5 FEET ABOVE FLOOD
STAGE AND STILL RISING.

ALL RESIDENTS OF LANCASTER COUNTY SHOULD BE PREPARED TO MOVE TO HIGHER
GROUND SHOULD FLOOD WATERS APPROACH.

IF YOU MUST DRIVE...DO NOT DRIVE THOUGH FLOODED ROADS IT COULD BE
THE LAST TRIP YOU WILL EVER MAK.E.

CURLL WSO HARRISBURG

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 8, 11:25 PM EDTFlash Flood WarningCTPLancaster3 hr

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.