Alert archive / Pennsylvania / Flash Flood Warnings in 1990

Flash Flood Warning 121, NWS Pittsburgh, PA

December 30, 19905 counties in Pennsylvania

NWS Pittsburgh, PA issued this flash flood warning at Dec 30, 1990, 12:30 PM EST for 5 counties in Pennsylvania. It was in force for 5 hr.

The area

The counties it named.

The facts

Issued
Dec 30, 1990, 12:30 PM EST (17:30 UTC)
Expired
Dec 30, 1990, 5:00 PM EST
In force
5 hr
Issued by
NWS Pittsburgh, PA
Area
Whole counties

Counties Allegheny County, PA, Armstrong County, PA, Butler County, PA, Clarion 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

Buffalo Intl Airport, NY (KBUF), launched 12:00Z, 5.5 hours before the alert went out and 256 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, Buffalo Intl Airport, NY at 12:00Z on 1990-12-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Buffalo Intl Airport, NY at 12:00Z on 1990-12-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 601 square meters per square second.1939587897Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
536 m above ground
0-6 km bulk shear
88 kt
0-1 km storm-relative helicity
601 m²/s²
0-3 km storm-relative helicity
765 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 301726
FFWPIT
PAC003-007-005-019-031-129-WVC029-009-302200-
 
BULLETIN - EBS ACTIVATION REQUESTED
FLOOD WARNING
NATIONAL WEATHER SERVICE PITTSBURGH PA
1230 PM EST SUN DEC 30 1990
 
THE NATIONAL WEATHER SERVICE IN PITTSBURGH HAS EXTENDED THE 
FLOOD WARNING EFFECTIVE UNTIL  500 PM EST
FOR THE FOLLOWING LOCATIONS...
 
IN WEST PENNSYLVANIA
 
   ...ALLEGHENY COUNTY...ARMSTRONG COUNTY...BEAVER COUNTY
   ...BUTLER COUNTY...CLARION COUNTY...WESTMORELAND COUNTY...

IN THE WEST VIRGINIA PANHANDLE

   ...BROOKE COUNTY...HANCOCK COUNTY

HEAVY RAINS CONTINUE TO FALL OVER THE WARNED COUNTIES AND WIDESPREAD
STREAM...CREEK...ROADWAY AND BASEMENT FLOODING HAS BEEN REPORTED.

ESPECIALLY HARD HIT IS BEAVER...ARMSTRONG...HANCOCK...
NORTHERN ALLEGHENY AND NORTHEASTERN WESTMORELAND COUNTIES.

RAINFALL OF BETWEEN 1.50 AND 2.00 INCHES HAVE BEEN COMMON OVER THE
WARNED AREA THIS MORNING. MUCH OF IT FALLING IN JUST 3 TO 4 HOURS.

ADDITIONAL HEAVY RAINFALL THIS AFTERNOON WILL CAUSE MORE EXTENSIVE
FLOODING.  

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY.  THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO
CROSS SAFELY.  VEHICLES CAUGHT IN RISING WATER SHOULD BE
ABANDONED QUICKLY.  MOVE TO HIGHER GROUND.

A FLOOD WARNING MEANS THAT FLOODING IS OCCURING OR IS IMMINENT.
MOST 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 STR:EAM...EVEN A SMALL ONE...ON FOOT. TO ESCAPE RISING
WATER MOVE TO HIGHER GROUND.

PALKO

The office that day

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

IssuedProductOfficeCountiesLasted
Dec 30, 8:46 AM ESTFlash Flood WarningPBZAllegheny4 hr
Dec 30, 8:46 AM ESTFlash Flood WarningPBZClarion4 hr
Dec 30, 9:04 AM ESTFlash Flood WarningPBZBeaver, Butler4 hr
Dec 30, 9:04 AM ESTFlash Flood WarningPBZArmstrong4 hr
Dec 30, 10:41 AM ESTFlash Flood WarningPBZWestmoreland5 hr
Dec 30, 12:30 PM ESTFlash Flood WarningPBZBeaver5 hr
Dec 30, 12:55 PM ESTFlash Flood WarningPBZButler4 hr
Dec 30, 4:30 PM ESTFlash Flood WarningPBZAllegheny, Armstrong, Butler, Westmoreland6 hr
Dec 30, 4:30 PM ESTFlash Flood WarningPBZBeaver6 hr
Dec 30, 4:30 PM ESTFlash Flood WarningPBZClarion6 hr

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.