Alert archive / Pennsylvania / Flash Flood Warnings in 1991

Flash Flood Warning 21, NWS Pittsburgh, PA

December 3, 1991Cambria County, Westmoreland County, Pennsylvania

NWS Pittsburgh, PA issued this flash flood warning at Dec 3, 1991, 1:26 AM EST for Cambria County, Westmoreland County, Pennsylvania. It was in force for 3 hr.

The area

The counties it named.

The facts

Issued
Dec 3, 1991, 1:26 AM EST (06:26 UTC)
Expired
Dec 3, 1991, 4:30 AM EST
In force
3 hr
Issued by
NWS Pittsburgh, PA
Area
Whole counties

Counties Cambria County, PA, Westmoreland County, PA

The nearest sounding before it

Pittsburgh, PA (KPIT), launched 00:00Z, 6.4 hours before the alert went out and 85 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 00:00Z on 1991-12-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 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 00:00Z on 1991-12-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 414 square meters per square second.1939587897Sfc1 km3 km6 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
2 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
500 m above ground
0-6 km bulk shear
93 kt
0-1 km storm-relative helicity
414 m²/s²
0-3 km storm-relative helicity
784 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 KPIT 030626
FFWPIT
PAC021-051-129-030930-
 
FLOOD WARNING
NATIONAL WEATHER SERVICE PITTSBURGH PA
126 AM EST TUE DEC 3 1991
 
THE NATIONAL WEATHER SERVICE IN PITTSBURGH HAS ISSUED A
FLOOD WARNING EFFECTIVE UNTIL  430 AM EST
FOR THE FOLLOWING LOCATIONS...
 
IN WEST PENNSYLVANIA
 
   ...CAMBRIA COUNTY...FAYETTE COUNTY...WESTMORELAND COUNTY
 
RAINS IN EXCESS OF 2 INCHES SINCE EARLY MONDAY EVENING HAVE CAUSED
POOR DRAINAGE FLOODING. CONTINUED HEAVY RAIN EARLY THIS TUESDAY
MORNING WILL CAUSE SOME SMALL STREAMS AND CREEKS TO FLOOD ALSO.
 
A FLASH FLOOD WARNING MEANS THAT FLOODING IS OCCURRING OR IS
IMMINENT.  MOST FLASH FLOOD DEATHS OCCUR IN AUTOMOBILES.  DO NOT
ATTEMPT TO CROSS BRIDGES...DIPS...OR LOW SPOTS IF WATER COVERS
THE ROADWAY.  NEVER TRY TO CROSS A FLOWING STREAM...EVEN A SMALL
ONE...ON FOOT.  TO ESCAPE RISING WATER MOVE UP TO HIGHER GROUND.

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, Dec 2, 10:31 PM EST, 2 hours 55 minutes before
PAZ004-030900-

SPECIAL WEATHER STATEMENT...WINTER STORM WARNING...
NATIONAL WEATHER SERVICE PITTSBURGH PA
1030 PM EST MON DEC 2 1991

...WINTER STORM WARNING TONIGHT FOR THE NORTHERN MOUNTAINS OF WESTERN
PENNSYLVANIA...

A WINTER STORM WARNING HAS BEEN ISSUED FOR THE NORTHERN MOUNTAINS OF
WESTERN PENNSYLVANIA FOR DAMAGING ACCUMULATIONS OF ICE. REPORTS OF
DOWNED TREES AND POWERLINES HAVE BEEN RECEIVED FROM MCKEAN AND ELK
COUNTIES IN THE WARNED AREA.

TRAVELING THROUGH THE NORTHERN MOUNTAINS IS NOT ADVISABLE EVEN AFTER
AFTER THE FREEZING RAIN CHANGES TO ALL RAIN. RAIN WILL COVER THE ICE
MAKING IT DIFFICULT TO SEE THE SLICK SPOTS. BRIDGES AND OVERPASSES
WILL BE ESPECIALLY DANGEROUS. POWER OUTAGES FROM DOWNED TREES AND
LINES CAN ALSO BE EXPECTED.

FREEZING RAIN WILL CHANGE OVER TO ALL RAIN IN THE EARLY MORNING HOURS
BUT ICY CONDITIONS WILL PERSIST UNTIL THE RAIN WASHES AWAY THE
ACCUMULATING ICE.

A FLOOD WATCH FOR STREAMS AND CREEKS IS ALSO IN EFFECT OVERNIGHT
FOR MUCH OF WESTERN PENNSYLVANIA AS WELL AS THE NORTHERN PANHANDLE
OF WEST VIRGINIA.

WJD/RWH
Special weather statement, Dec 3, 1:07 AM EST, 19 minutes before
PAZ001>006-013>015-WVZ001-030800-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY...
NATIONAL WEATHER SERVICE PITTSBURGH PA
100 AM EST TUE DEC 3 1991

...FLOOD WARNINGS FOR GREENE AND WASHINGTON COUNTIES UNTIL 430 AM...
...FLOOD WARNING FOR MARSHAL COUNTY OF WEST VIRGINIA UNTIL 400 AM...
...FLOOD WATCH FOR STREAMS AND CREEKS TONIGHT FOR SOUTHWEST...SOUTH
   CENTRAL...AND THE LAUREL MOUNTAINS OF PENNSYLVANIA AS WELL AS THE
   NORTHERN PANHANDLE OF WEST VIRGINIA...
...WINTER WEATHER ADVISORIES FOR FREEZING RAIN IN NORTHWEST PENNSYLVANIA
   NORTH OF INTERSTATE 80...

AT 1255 AM WEATHER RADAR SHOWED RAIN OVER WESTERN AND CENTRAL
PENNSYLVANIA...CENTRAL AND EASTERN OHIO...AND NORTHERN WEST VIRGINIA.
IN THE BRADFORD...WARREN...AND DUBOIS AREAS FREEZING RAIN AND SLEET WAS
FALLING.

THE AREA OF PRECIPITATION EXTENDED FROM ERIE PENNSYLVANIA...SOUTH TO
CLARKSBURG WEST VIRGINIA...AND FROM COLUMBUS OHIO...EAST TO STATE
COLLEGE PENNSYLVANIA.  HEAVIER RAIN CONTINUED TO MOVE OVER MARSHALL
COUNTY IN THE NORTHERN PANHANDLE OF WEST VIRGINIA...AND GREENE AND
WASHINGTON COUNTIES OF SOUTHWEST PENNSYLVANIA.  HERE...HEAVY RAINS
HAVE SATURATED THE GROUND AND POOR DRAINAGE FLOODING HAS BEGUN.
CREEKS WERE AT BANKFULL IN MARSHALL COUNTY.

IN NORTHWEST PENNSYLVANIA...ICE IS ACCUMULATING.  TREES AND POWER LINES
WERE REPORTED DOWN IN MCKEAN AND ELK COUNTIES.

OVER THE PAST HOUR...COVERAGE OF THE PRECIPITATION REMAINED WIDESPREAD
AND INTENSITIES STAYED THE SAME.  MOVEMENT WAS TOWARD THE NORTHEAST AT
45 MPH.

REHAK

The office that day

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

IssuedProductOfficeCountiesLasted
Dec 3, 12:28 AM ESTFlash Flood WarningPBZGreene, Washington4 hr
Dec 3, 1:26 AM ESTFlash Flood WarningPBZFayette3 hr
Dec 3, 7:46 AM ESTFlash Flood WarningPBZGreene, Washington2 hr

Nearby

Flash Flood Warnings in Pennsylvania, 1991Every flash flood warning in 1991

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.