Alert archive / Pennsylvania / Flash Flood Warnings in 1990

Flash Flood Warning 96, NWS Pittsburgh, PA

August 19, 1990Westmoreland County, Pennsylvania

NWS Pittsburgh, PA issued this flash flood warning at Aug 19, 1990, 10:50 PM EDT for Westmoreland County, Pennsylvania. It was in force for 2 hr.

The area

The counties it named.

The facts

Issued
Aug 19, 1990, 10:50 PM EDT (02:50 UTC)
Expired
Aug 20, 1990, 1:00 AM EDT
In force
2 hr
Issued by
NWS Pittsburgh, PA
Area
Whole counties

County 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 00:00Z, 2.8 hours before the alert went out and 55 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 1990-08-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 356 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 00:00Z on 1990-08-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 17 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
356 J/kg
Mixed-layer CIN
-40 J/kg
Mixed-layer LCL
665 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
17 m²/s²
0-3 km storm-relative helicity
20 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KPIT 200303 COR
FFWPIT
PAC129-200500-

BULLETIN  BROADCAST IMMEDIATELY
FLASH FLOOD WARNING...CORRECTED
NATIONAL WEATHER SERVICE PITTSBURGH PA
1102 PM EDT SUN AUG 19 1990

THE NATIONAL WEATHER SERVICE IN PITTSBURGH HAS ISSUED A FLASH FLOOD
WARNING UNTIL 1 AM MONDAY FOR THIS COUNTY IN

SOUTHWESTERN PENNSYLVANIA...WESTMORELAND.

A FLASH FLOOD WARNING MEANS FLOODING IS IMMINENT OR IN PROGRESS.
DO NOT DRIVE THROUGH FLOODED AREAS.

THUNDERSTORMS HAVE FORMED ONCE AGAIN IN THE NORTHWEST PART OF
WESTMORELAND COUNTY. THE EMERGENCY OPERATIONS CENTER SAYS BASEMENTS
AND ROADS ARE BEING FLOODED BY HEAVY RAIN IN LOWER BURRELL TOWNSHIP
NEAR NEW KENSINGTON. THE STORMS WILL BE MOVING SLOWLY SOUTHEASTWARD
AT 20 MPH.
A FLASH9 FLOOD WATCH CONTINUES TIL 5 AM MONDAY FOR A LARGE PART OF
SOUTHWESTERN PENNSYLVANIA AND THE NORTHERN PANHANDLE OF WEST
VIRGINIA.

CORRECTED TO DELETE ANY REFERENCE TO SEVERE THUNDERSTORM WARNING.
THIS IS A FLASH FLOOD WARNING ONLY.

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 19, 8:05 PM EDTFlash Flood WarningPBZFayette, Westmoreland81 min

Nearby

Flash Flood Warnings in Pennsylvania, 1990Every flash flood warning in 1990

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.