Alert archive / Pennsylvania / Flash Flood Warnings in 1990

Flash Flood Warning 2, NWS Pittsburgh, PA

May 15, 1990Armstrong County, Butler County, Pennsylvania

NWS Pittsburgh, PA issued this flash flood warning at May 15, 1990, 4:53 PM EDT for Armstrong County, Butler County, Pennsylvania. It was in force for 3 hr.

The area

The counties it named.

The facts

Issued
May 15, 1990, 4:53 PM EDT (20:53 UTC)
Expired
May 15, 1990, 8:00 PM EDT
In force
3 hr
Issued by
NWS Pittsburgh, PA
Area
Whole counties

Counties Armstrong County, PA, 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, 8.9 hours before the alert went out and 61 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 1990-05-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 61 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 1990-05-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 177 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
61 J/kg
Mixed-layer CIN
-163 J/kg
Mixed-layer LCL
1172 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
177 m²/s²
0-3 km storm-relative helicity
195 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 152057 COR
FFWPIT
PAC005-019-000-160000-

BULLETIN  BROADCAST IMMEDIATELY
FLASH FLOOD WARNING...CORRECTED PARAGRAPH 3 ...THE SAME AREA...
NATIONAL WEATHER SERVICE PITTSBURGH PA
453 PM EDT TUE MAY 15 1990

THE NATIONAL WEATHER SERVICE IN PITTSBURGH HAS ISSUED A FLASH FLOOD
WARNING UNTIL 8 PM FOR THESE COUNTIES IN

WESTERN PENNSYLVANIA...BUTLER AND ARMSTRONG.

AT 453 PM RADAR SHOWED THUNDERSTORMS MOVING OVER THE SAME AREA
REPEATEDLY. THE HEAVIEST RAIN EXTENDS FROM MORAINE STATE PARK IN
BUTLER COUNTY TO KITTANNING IN EASTERN ARMSTRONG COUNTY.

IF MORE THAN 1.5 INCHES OF RAIN SHOULD FALL IN A SHORT TIME...
FLOODING WILL BEGIN.

A FLASH FLOOD WATCH CONTINUES UNTIL 10 PM FOR 8 COUNTIES FROM
LAWRENCE COUNTY TO CENTRE COUNTY IN WEST CENTRAL PENNSYLVANIA.

A FLASH FLOOD WARNING MEANS FLOODING IS IMMINENT OR IN PROGRESS.
IF YOU GET ANY INDICATION THAT FLOOD WATERS ARE APPROACHING..MOVE TO
HIGHER GROUND IMMEDIATELY. DO NOT DRIVE THROUGH FLOODED AREAS.

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, May 15, 3:49 PM EDT, 1 hour 4 minutes before
PAZ001>006-013>015-WVZ001-160300-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE PITTSBURGH PA
345 PM EDT SUN MAY 13 1990

...THUNDERSTORMS WITH HEAVY DOWNPOURS HAIL GUSTY WIND AND DANGEROUS
LIGHTNING DEVELOPING OVER WESTERN PENNSYLVANIA LATE THIS AFTERNOON AND
TONIGHT...

JUST BEFORE 4 PM PITTSBURGH WEATHER RADAR SHOWED THUNDERSTORMS IN
WESTERN PENNSYLVANIA ALONG A LINE FROM LAWRENCE COUNTY EASTWARD THROUGH
BUTLER AND ARMSTRONG COUNTIES TO CLEARFIELD AND CENTRE COUNTIES.  SOME
AREAS IN THESE COUNTIES MAY GET REPEATED HEAVY DOWNPOURS THROUGH 6 PM
WHICH MAY RESULT IN ROADWAY AND OTHER POOR DRAINAGE TYPE FLOODING.  SO
USE EXTRA CAUTION.  STRONG WIND GUSTS AND DANGEROUS LIGHTNING ARE ALSO
POSSIBLE.  WHEN A THUNDERSTORM APPROACHES...ITS SAFEST TO GO INSIDE.

OTHER THUNDERSTORMS WILL BE DEVELOPING ACROSS WESTERN PENNSYLVANIA AND
THE NORTHERN WEST VIRGINIA PANHANDLE THIS EVENING AND TONIGHT.  SO BE
ON THE LOOKOUT FOeR THUNDERSTORMS AND LISTEN FOR FURTHER ADVISORIES.

GIORDANO/STAIRS/REHAK

The office that day

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

IssuedProductOfficeCountiesLasted
May 15, 3:58 PM EDTSevere Thunderstorm WarningPBZArmstrong62 min
May 15, 6:02 PM EDTSevere Thunderstorm WarningPBZClarion58 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.