Alert archive / Pennsylvania / Flash Flood Warnings in 1990

Flash Flood Warning 45, NWS Pittsburgh, PA

July 10, 1990Jefferson County, Pennsylvania

NWS Pittsburgh, PA issued this flash flood warning at Jul 10, 1990, 1:50 PM EDT for Jefferson County, Pennsylvania. It was in force for 93 min.

The area

The counties it named.

The facts

Issued
Jul 10, 1990, 1:50 PM EDT (17:50 UTC)
Expired
Jul 10, 1990, 3:23 PM EDT
In force
93 min
Issued by
NWS Pittsburgh, PA
Area
Whole counties

County Jefferson 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, 5.8 hours before the alert went out and 122 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 1990-07-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 370 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 1990-07-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -37 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
370 J/kg
Mixed-layer CIN
-70 J/kg
Mixed-layer LCL
678 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
-37 m²/s²
0-3 km storm-relative helicity
8 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 101752
FFWPIT
PAC019-005-065-063-033-102100-

BULLETIN - EBS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PITTSBURGH PA
150 PM EDT TUE JUL 10 1990

THE NATIONAL WEATHER SERVICE IN PITTSBURGH HAS ISSUED A
FLASH FLOOD WARNING EFFECTIVE UNTIL 500PM EDT
FOR THE FOLLOWING COUNTIES....

IN WEST PENNSYLVANIA

...BUTLER COUNTY...ARMSTRONG COUNTY...NORTHERN INDIANA COUNTY...
SOUTHERN CLEARFIELD COUNTY...AND SOUTHERN JEFFERSON COUNTY.

SINCE 10AM THIS MORNING NEARLY 2 INCHES OF RAIN HAS FALLEN AT THE
MAHONING DAM RESERVOIR IN EXTREME NORTHERN ARMSTRONG COUNTY WITH
WEATHER SERVICE RADAR INDICATING A LINE OF SHOWERS AND THUNDERSTORMS
DEVELOPING AND MOVING SOUTHEASTWARD ACROSS THIS WARNING AREA WHERE
HEAVIER RAINS FELL YESTERDAY AND SOILS ARE SATURATED.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT.  IT'S
IMPORTANT TO KNOW WHERE YOU ARE RELATIVE TO STREAMS...RIVERS...OR
CREEKS WHICH CAN BECOME KILLERS IN HEAVY RAINS.  CAMPERS SHOULD
AVOID CAMPING ALONG STREAMS OR CREEKS DURING THREATENING RAINS.

MOST DEATHS IN FLASH FLOODING 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...5EVEN A
SMALL ONE...ON FOOT.

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, Jul 10, 10:40 AM EDT, 3 hours 10 minutes before
PAZ001>006-013>015-WVZ001-101900-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PITTSBURGH PA
1040AM EDT TUE JUL 10 1990

...HIGH HUMIDITY CONTINUES ACROSS THE REGION WITH THE THREAT FOR
MORE SHOWERS AND THUNDERSTORMS...

HEAVY RAINS SOAKED THE REGION YESTERDAY ALONG WITH SEVERE THUNDERSTORMS
THAT RESULTED IN SOME FLOODING...DANGEROUS LIGHTNING...GUSTY WINDS
AND SOME HAIL.

RAINFALL AMOUNTS OF 1.5 TO 3.0 INCHES WERE COMMON ACROSS SOME COUNTIES
IN WESTERN PENNSYLVANIA YESTERDAY NAMELY
CRAWFORD...VENANGO...FOREST...MCKEAN...CAMERON...CLEARFIELD...BEAVER...
ALLEGHENY...BUTLER...ARMSTRONG...CLARION...JEFFERSON...INDIANA...
SOMERSET AND FAYETTE.
THE HEAVIEST RAIN REPORTED WAS 5.10 INCHES AT LOCK 8 MOSGROVE IN
ARMSTRONG COUNTY BETWEEN 1 AND 5PM YESTERDAY AFTERNOON.

SHOWERS AND THUNDERSTORMS WILL REDEVELOP ACROSS THE REGION
DURING THE AFTERNOON AND EVENING HOURS. HEAVY DOWNPOURS ARE POSSIBLE
WITH THESE STORMS.
THE AREAS THAT SEEM MOST VULNERABLE FOR HEAVY RAINS WILL BE THE
SOUTHERN HALF OF WESTERN PENNSYLVANIA AND THE NORTHERN WEST VIRGINIA
PANHANDLE.

ALTHOUGH NO WATCHES ARE IN EFFECT PRESENTLY...A FLASH FLOOD WATCH
MAY HAVE TO BE ISSUED DURING THE AFTERNOON OR EVENING FOR
THE NORTHERN WEST VIRGINIA PANHANDLE...SOUTHWESTERN PENNSYLVANIA...
THE LAUREL AND SOUTH CENTRAL MOUNTAINS AND THE SOUTH CENTRAL AREA.

THIS SYSTEM WILL BE CLOSELY MONITORED. LISTEN FOR FURTHER STATMENTS
AND ADVISORIES.

SISK/HIGGINS/RUMBURGi

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 10, 1:50 PM EDTFlash Flood WarningPBZArmstrong, Butler, Indiana3 hr
Jul 10, 1:50 PM EDTFlash Flood WarningPBZClearfield3 hr
Jul 10, 3:40 PM EDTSevere Thunderstorm WarningPBZButler65 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.