Alert archive / Pennsylvania / Flash Flood Warnings in 1990

Flash Flood Warning 41, NWS Pittsburgh, PA

July 9, 1990Allegheny County, Armstrong County, Beaver County, Pennsylvania

NWS Pittsburgh, PA issued this flash flood warning at Jul 9, 1990, 4:36 PM EDT for Allegheny County, Armstrong County, Beaver County, Pennsylvania. It was in force for 114 min.

The area

The counties it named.

The facts

Issued
Jul 9, 1990, 4:36 PM EDT (20:36 UTC)
Expired
Jul 9, 1990, 6:30 PM EDT
In force
114 min
Issued by
NWS Pittsburgh, PA
Area
Whole counties

Counties Allegheny County, PA, Armstrong County, PA, Beaver 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, 8.6 hours before the alert went out and 31 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 1990-07-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1312 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 1990-07-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 143 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
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 092037
FFWPIT
PAC003-005-007-092230-
 
BULLETIN - EBS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PITTSBURGH PA
436 PM EDT MON JUL 9 1990
 
THE NATIONAL WEATHER SERVICE IN PITTSBURGH HAS ISSUED A
FLASH FLOOD WARNING EFFECTIVE UNTIL  630 PM EDT
FOR THE FOLLOWING LOCATIONS...
 
IN WEST PENNSYLVANIA
 
   ...ALLEGHENY COUNTY...ARMSTRONG COUNTY...BEAVER COUNTY
 
AT 435 PM WEATHER RADAR SHOWED THUNDERSTORMS STILL OVER THESE COUNTIES 
FLOODING IS STILL OCCURING ON THE SOUTH FORK OF MONTOUR RUN IN
ALLEGHENY COUNTY.
 
IN BEAVER COUNTY...FLOODING IS OCCURING NEAR BRIDGEWATER AND ROCHESTER
ALONG SMALL STREAMS.
 
SMALL STREAM FLOODING IS ALSO OCCURING IN ARMSTRONG COUNTY IN PINE
TOWNSHIP NEAR MOSSGROVE AND TEMPLETON.
 
 
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 FLASH FLOOD WARNING MEANS THAT FLOODING IS OCCURRING OR IS
IMMINENT.  MOST FLASH 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 STREAM...EVEN A SMALL
ONE...ON FOOT.  TO ESCAPE RISING WATER MOVE UP TO HIGHER GROUND.
 
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 KIjLLERS IN HEAVY RAINS.  CAMPERS SHOULD
AVOID CAMPING ALONG STREAMS OR CREEKS DURING THREATENING RAINS.

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 9, 12:54 PM EDTFlash Flood WarningPBZClarion, Jefferson2 hr
Jul 9, 12:54 PM EDTSevere Thunderstorm WarningPBZClarion, Jefferson2 hr
Jul 9, 1:12 PM EDTFlash Flood WarningPBZClearfield108 min
Jul 9, 1:12 PM EDTFlash Flood WarningPBZArmstrong108 min
Jul 9, 1:21 PM EDTSevere Thunderstorm WarningPBZClearfield99 min
Jul 9, 1:21 PM EDTSevere Thunderstorm WarningPBZArmstrong99 min
Jul 9, 1:35 PM EDTSevere Thunderstorm WarningPBZBeaver, Butler85 min
Jul 9, 2:09 PM EDTSevere Thunderstorm WarningPBZAllegheny81 min
Jul 9, 3:00 PM EDTFlash Flood WarningPBZArmstrong, Butler2 hr
Jul 9, 3:01 PM EDTFlash Flood WarningPBZAllegheny, Beaver89 min
Jul 9, 3:01 PM EDTSevere Thunderstorm WarningPBZAllegheny, Beaver89 min
Jul 9, 3:50 PM EDTFlash Flood WarningPBZWashington, Westmoreland100 min
Jul 9, 3:50 PM EDTSevere Thunderstorm WarningPBZWashington, Westmoreland100 min
Jul 9, 4:57 PM EDTSevere Thunderstorm WarningPBZSomerset48 min
Jul 9, 6:29 PM EDTFlash Flood WarningPBZArmstrong3 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.