Alert archive / Pennsylvania / Flash Flood Warnings in 1989

Flash Flood Warning 39, NWS Pittsburgh, PA

August 23, 1989Fayette County, Westmoreland County, Pennsylvania

NWS Pittsburgh, PA issued this flash flood warning at Aug 23, 1989, 7:30 PM EDT for Fayette County, Westmoreland County, Pennsylvania. It was in force for 3 hr.

The area

The counties it named.

The facts

Issued
Aug 23, 1989, 7:30 PM EDT (23:30 UTC)
Expired
Aug 23, 1989, 10:00 PM EDT
In force
3 hr
Issued by
NWS Pittsburgh, PA
Area
Whole counties

Counties Fayette County, PA, Westmoreland 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

Pittsburgh, PA (KPIT), launched 12:00Z, 11.5 hours before the alert went out and 57 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, Pittsburgh, PA at 12:00Z on 1989-08-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 90 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, Pittsburgh, PA at 12:00Z on 1989-08-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 0 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
90 J/kg
Mixed-layer CIN
-61 J/kg
Mixed-layer LCL
783 m above ground
0-6 km bulk shear
0 kt
0-1 km storm-relative helicity
0 m²/s²
0-3 km storm-relative helicity
0 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

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, Aug 23, 6:26 PM EDT, 1 hour 4 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PITTSBURGH, PA
625 PM EDT WED AUG 23 1989

...THUNDERSTORMS WITH HEAVY DOWNPOURS MOVING INTO WASHINGTON...
   FAYETTE AND SOMERSET COUNTIES...

THUNDERSTORMS WITH HEAVY DOWNPOURS WILL MOVE ACROSS WASHINGTON...
FAYETTE...SOMERSET AND GREENE COUNTIES BETWEEN 630 AND 730 PM.

THE HEAVY DOWPOURS MAY CAUSE PONDING OF WATER ON ROAD SURFACES
AND FLOODING IN POOR DRAINAGE AREAS.

SOME OF THESE THUNDERSTOjRMS WILL BE ACCOMPANIED BY STRONG GUSTY
WINDS AND DANGEROUS LIGHTNING.

IF THREATENING WEATHER APPROACHES...GO TO A SAFE PLACE IMMEDIATELY.

DO NOT DRIVE THROUGH FLOODED AREAS.

DAVIS
Special weather statement, Aug 23, 6:34 PM EDT, 56 minutes before
SPECIAL WEATHER STATEMENT CORRECTED
NATIONAL WEATHER SERVICE PITTSBURGH, PA
632 PM EDT WED AUG 23 1989

...THUNDERSTORMS WITH HEAVY DOWNPOURS MOVING INTO WASHINGTON...
   FAYETTE GREENE AND SOMERSET COUNTIES...

THUNDERSTORMS WITH HEAVY DOWNPOURS...NOW IN SOUTHERN WESTMORELAND
COUNTY...WILL MOVE ACROSS WASHINGTON...FAYETTE...SOMERSET AND GREENE
COUNTIES IN WESTERN PENNSYLVANIA BETWEEN 630 AND 730 PM.

THE HEAVY DOWPOURS MAY CAUSE PONDING OF WATER ON ROAD SURFACES
AND FLOODING IN POOR DRAINAGE AREAS.

SOME OF THESE THUNDERSTORMS WILL BE ACCOMPANIED BY STRONG GUSTY
WINDS AND DANGEROUS LIGHTNING.

IF THREATENING WEATHER APPROACHES...GO TO A SAFE PLACE IMMEDIATELY.

DO NOT DRIVE THROUGH FLOODED AREAS.
DAVIS
Special weather statement, Aug 23, 7:03 PM EDT, 27 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PITTSBURGH, PA
700 PM EDT WED AUG 23 1989

...HEAVY RAIN FALLS IN WESTMORELAND COUNTY ON SEWICKLEY CREEK...

THUNDERSTORMS WITH HEAVY DOWNPOURS THAT MOVED ACROSS SOUTHERN
WESTMORELAND COUNTY DROPPED AROUND TWO INCHES OF RAIN BETWEEN NEW
STANTON AND MOUNT PLEASANT IN THE SEWICKLEY CREEK WATERSHED.

SOME BASEMENT FLOODING WAS REPORTED IN MOUNT PLEASANT.

THREE AND A HALF INCHES OF RAIN IN THREE HOURS WOULD BE NEEDED TO
BRING STREAMS AND CREEKS OUT OF THEIR BANKS.  SOME RAPID RISES CAN
BE EXPECTED ON SEWICKLEY AND JACOBS CREEK FROM THE HEAVY RAIN.

THE HEAVY RAIN MAY CAUSE PONDING OF WATER ON ROAD SURFACES FLOODING IN
POOR DRAINAGE AREAS.

THE THUNDERSTORMS ARE SLIDING SLOWLY SOUTH OF WESTMORELAND COUNTY
INTO FAYETTE AND SOMERSET COUNTIES...EASING THE THREAT OF CREEK
FLOODING IN SOUTHERN WESTMORELAND COUNTY.

THE THUNDERSTORMS MAY BE ACCOMPANIED BY STRONG GUSTY WINDS AND
DANGEROUS LIGHTNING.

IF THREATENING WEATHER APPROACHES...GO TO A SAFE PLACE IMMEDIATELY.

DO NOT DRIVE THROUGH FLOODED AREAS.

DAVIS
Special weather statement, Aug 23, 7:09 PM EDT, 21 minutes before
SPECIAL WEATHER STATEMENT CORRECTED
NATIONAL WEATHER SERVICE PITTSBURGH, PA
707 PM EDT WED AUG 23 1989

...HEAVY RAIN FALLS IN WESTMORELAND COUNTY ON SEWICKLEY CREEK...

THUNDERSTORMS WITH HEAVY DOWNPOURS THAT MOVED ACROSS SOUTHERN
WESTMORELAND COUNTY IN WESTERN PENNSYLVANIA DROPPED AROUND TWO INCHES
OF RAIN IN ONE HOUR BETWEEN NEW STANTON AND MOUNT PLEASANT IN THE
SEWICKLEY CREEK WATERSHED.  SOME BASEMENT FLOODING WAS REPORTED IN
MOUNT PLEASANT.

THREE AND A HALF INCHES OF RAIN IN THREE HOURS WOULD BE NEEDED TO
BRING STREAMS AND CREEKS OUT OF THEIR BANKS.  SOME RAPID RISES CAN
BE EXPECTED ON SEWICKLEY AND JACOBS CREEK FROM THE HEAVY RAIN.

THE HEAVY RAIN MAY CAUSE PONDING OF WATER ON ROAD SURFACES AND FLOODING
IN POOR DRAINAGE AREAS.

THE THUNDERSTORMS ARE SLIDING SLOWLY SOUTH OF WESTMORELAND COUNTY
INTO FAYETTE AND SOMERSET COUNTIES...EASING THE THREAT OF CREEK
FLOODING IN SOUTHERN WESTMORELAND COUNTY.

THE THUNDERSTORMS MAY BE ACCOMPANIED BY STRONG GUSTY WINDS AND
DANGEROUS LIGHTNING.

IF THREATENING WEATHER APPROACHES...GO TO A SAFE PLACE IMMEDIATELY.

DO NOT DRIVE THROUGH FLOODED AREAS.

DAVIS

Nearby

Flash Flood Warnings in Pennsylvania, 1989Every flash flood warning in 1989

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.