Alert archive / Pennsylvania / Flash Flood Warnings in 1990

Flash Flood Warning 83, NWS Pittsburgh, PA

July 20, 1990Butler County, Pennsylvania

NWS Pittsburgh, PA issued this flash flood warning at Jul 20, 1990, 6:29 PM EDT for Butler County, Pennsylvania. It was in force for 2 hr.

The area

The counties it named.

The facts

Issued
Jul 20, 1990, 6:29 PM EDT (22:29 UTC)
Expired
Jul 20, 1990, 8:30 PM EDT
In force
2 hr
Issued by
NWS Pittsburgh, PA
Area
Whole counties

County Butler 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, 10.5 hours before the alert went out and 58 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 1990-07-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 66 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 1990-07-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 96 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
66 J/kg
Mixed-layer CIN
-90 J/kg
Mixed-layer LCL
1131 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
96 m²/s²
0-3 km storm-relative helicity
117 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 202230
FFWPIT
PAC019-210030-
 
BULLETIN - EBS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PITTSBURGH PA
629 PM EDT FRI JUL 20 1990
 
THE NATIONAL WEATHER SERVICE IN PITTSBURGH HAS ISSUED A
FLASH FLOOD WARNING EFFECTIVE UNTIL  830 PM EDT
FOR THE FOLLOWING LOCATION...
 
IN WEST PENNSYLVANIA
 
   ...BUTLER COUNTY
 
RADAR AT 630 PM SHOWED A VERY HEAVY THUNDERSTORM MOVING INTO BUTLER
COUNTY. THIS STORM HAS PRODUCED STREET FLOODING IN COLUMBIANA COUNTY
OF OHIO. BUTLER COUNTY HAS ALREADY RECEIVED HEAVY RAINS EARLIER TODAY
SO ANY ADDITIONAL HEAVY RAINS WILL CAUSE FLASH FLOODING.
 
 
MOST DEATHS IN FLASH FLOODING OCCUR IN AUTOMOBILES.  DO NOT
ATTEMPT TO CROSS BRIDGES...DIPS...OR LOW SP]OTS IF WATER COVERS
THE ROADWAY.  NEVER TRY TO CROSS A FLOWING STREAM...EVEN A
SMALL ONE...ON FOOT.

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 20, 2:12 PM EDTSevere Thunderstorm WarningPBZArmstrong, Butler, Clarion63 min
Jul 20, 2:55 PM EDTFlash Flood WarningPBZWestmoreland65 min
Jul 20, 2:55 PM EDTSevere Thunderstorm WarningPBZWestmoreland65 min
Jul 20, 4:12 PM EDTSevere Thunderstorm WarningPBZCambria63 min
Jul 20, 4:12 PM EDTSevere Thunderstorm WarningPBZGreene63 min
Jul 20, 4:24 PM EDTSevere Thunderstorm WarningPBZSomerset66 min
Jul 20, 5:01 PM EDTFlash Flood WarningPBZFayette, Somerset119 min
Jul 20, 5:01 PM EDTSevere Thunderstorm WarningPBZFayette, Somerset119 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.