Alert archive / Pennsylvania / Flash Flood Warnings in 1990

Flash Flood Warning 40, NWS Pittsburgh, PA

July 9, 1990Washington County, Westmoreland County, Pennsylvania

NWS Pittsburgh, PA issued this flash flood warning at Jul 9, 1990, 3:50 PM EDT for Washington County, Westmoreland County, Pennsylvania. It was in force for 100 min.

The area

The counties it named.

The facts

Issued: Jul 9, 1990, 3:50 PM EDT (19:50 UTC)
Expired: Jul 9, 1990, 5:30 PM EDT
In force: 100 min
Issued by: NWS Pittsburgh, PA
Area: Whole counties

Counties Washington 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

Pittsburgh, PA (KPIT), launched 12:00Z, 7.8 hours before the alert went out and 27 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1312 J/kg
Mixed-layer CIN: -49 J/kg
Mixed-layer LCL: 1037 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 143 m²/s²
0-3 km storm-relative helicity: 130 m²/s²
Significant tornado parameter: 0.6
Supercell composite: 5.3

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KPIT 091952
FFWPIT
PAC125-129-092130-
 
BULLETIN - EBS ACTIVATION REQUESTED
SEVERE THUNDERSTORM AND FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PITTSBURGH PA
350 PM EDT MON JUL 9 1990
 
THE NATIONAL WEATHER SERVICE IN PITTSBURGH HAS ISSUED A
SEVERE THUNDERSTORM AND FLASH FLOOD WARNING
EFFECTIVE UNTIL  530 PM EDT
FOR THE FOLLOWING LOCATIONS...
 
IN WEST PENNSYLVANIA
 
   ...WASHINGTON COUNTY...WESTMORELAND COUNTY
 
AT 350 PM WEATHER SERVICE RADAR SHOWED SEVERE THUNDERSTORMS ENTERING
WASHINGTON COUNTY. ANOTHER STORM WAS MOVING INTO WESTMORELAND COUNTY.
 
HEAVY RAINS CAN CAUSE FLOODING...NEVER DRIVE INTO A FLOODED AREA.
 
IN ADDITION SEVERE THUNDERSTORM AND FLASH FLOOD WARNINGS ARE IN EFFECT
UNTIL 430 PM FOR ALLEGHENY AND BEAVER COUNTIES.
 
FLASH FLOOD WARNINGS ARE IN EFFECT UNTIL 500 PM FOR BUTLER AND
ARMSTRONG COUNTIES.
 
 
 
 
 
IF YOU ARE CAUGHT OUTSIDE...SEEK SHELTER FROM THE WEATHER IN A
STRONG BUILDING.  DAMAGING WIND...LARGE HAIL...VERY HEAVY RAIN...
AND DEADLY LIGHTNING ARE ALL POSSIBLE IN SEVERE THUNDERSTORMS.
STAY INSIDE AWAY FROM WINDOWS UNTIL THE STORM HAS PASSED.
 
SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 55
MPH...DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN.
FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR
OF YOUR HOME OR BUSINESS.  HEAVY RAINS FLOOD ROADS QUICKLY SO
DON'T DRIVE INTO AREAS WHERE WATER COVERS THE ROAD.
 
THIS IS A DANGEROUS STORM.  IF YOU ARE IN ITS PATH YOU SHOULD
PREPARE FOR DAMAGING WIND IN EXCESS OF 55 MPH...LARGE HAIL...AND
DEADLY LIGHTNING.  PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING BUT STAY AWAY FROM WINDOWS.
 
WHEN THUNDERSTORMS ARE OCCURRING...PEOPLE SHOULD MOVE INSIDE A
STRONG BUILDING.  DO NOT STAND BY WINDOWS.  DON'T USE TELEPHONES
OR ELECTRICAL APPLIANCES UNLESS IN AN EMERGENCY UNTIL THE STORM
HAS PASSED.  MOTORISTS SHOULD NOT DRIVE INTO LOW WATER CROSSINGS.

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 9, 12:54 PM EDT	Flash Flood Warning	PBZ	Clarion, Jefferson	2 hr
Jul 9, 12:54 PM EDT	Severe Thunderstorm Warning	PBZ	Clarion, Jefferson	2 hr
Jul 9, 1:12 PM EDT	Flash Flood Warning	PBZ	Clearfield	108 min
Jul 9, 1:12 PM EDT	Flash Flood Warning	PBZ	Armstrong	108 min
Jul 9, 1:21 PM EDT	Severe Thunderstorm Warning	PBZ	Clearfield	99 min
Jul 9, 1:21 PM EDT	Severe Thunderstorm Warning	PBZ	Armstrong	99 min
Jul 9, 1:35 PM EDT	Severe Thunderstorm Warning	PBZ	Beaver, Butler	85 min
Jul 9, 2:09 PM EDT	Severe Thunderstorm Warning	PBZ	Allegheny	81 min
Jul 9, 3:00 PM EDT	Flash Flood Warning	PBZ	Armstrong, Butler	2 hr
Jul 9, 3:01 PM EDT	Flash Flood Warning	PBZ	Allegheny, Beaver	89 min
Jul 9, 3:01 PM EDT	Severe Thunderstorm Warning	PBZ	Allegheny, Beaver	89 min
Jul 9, 3:50 PM EDT	Severe Thunderstorm Warning	PBZ	Washington, Westmoreland	100 min
Jul 9, 4:36 PM EDT	Flash Flood Warning	PBZ	Allegheny, Armstrong, Beaver	114 min
Jul 9, 4:57 PM EDT	Severe Thunderstorm Warning	PBZ	Somerset	48 min
Jul 9, 6:29 PM EDT	Flash Flood Warning	PBZ	Armstrong	3 hr

Nearby

Flash Flood Warnings in Pennsylvania, 1990 Every 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.