Alert archive / Pennsylvania / Flash Flood Warnings in 1998

Flash Flood Warning 23, NWS Pittsburgh, PA

January 9, 1998Washington County, Pennsylvania

NWS Pittsburgh, PA issued this flash flood warning at Jan 9, 1998, 1:39 AM EST for Washington County, Pennsylvania. It was in force for 2 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jan 9, 1998, 1:39 AM EST (06:39 UTC)
Expired
Jan 9, 1998, 4:00 AM EST
In force
2 hr
Issued by
NWS Pittsburgh, PA
Area
Whole counties

County Washington County, PA

The radar

The Pittsburgh radar (KPBZ), 38 km from the middle of the area, began a volume at 06:43 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Pittsburgh, PA (KPIT), launched 00:00Z, 6.7 hours before the alert went out and 28 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 00:00Z on 1998-01-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 598 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 00:00Z on 1998-01-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 80 square meters per square second.1939587897117136Sfc1 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
598 J/kg
Mixed-layer CIN
-3 J/kg
Mixed-layer LCL
551 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
80 m²/s²
0-3 km storm-relative helicity
95 m²/s²
Significant tornado parameter
0.2
Supercell composite
1.1

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KPIT 090641
FFWPIT
PAC125-090900-
 
BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PITTSBURGH PA
139 AM EST FRI JAN 9 1998
 
THE NATIONAL WEATHER SERVICE IN PITTSBURGH HAS ISSUED A
FLASH FLOOD WARNING EFFECTIVE UNTIL  400 AM EST
FOR THE FOLLOWING LOCATION...
 
IN WEST PENNSYLVANIA
 
   ...WASHINGTON COUNTY
 
THUNDERSTORMS WITH TORRENTIAL RAIN WERE MOVING THROUGH WESTERN
WASHINGTON COUNTY. SMALL STREAMS AND CREEKS WILL RISE QUICKLY AND
OVERFLOW THEIR BANKS. WATER WILL ALSO COLLECT QUICKLY IN LOW LYING
AREAS.
 
DO NOT DRIVE INTO AREAS WHERE THE WATER COVERS THE ROAD.  THE WATER
MAY BE TOO DEEP TO ALLOW YOUR CAR TO CROSS SAFELY.  VEHICLES CAUGHT
IN RISING WATER SHOULD BE ABANDONED QUICKLY.  MOVE TO HIGHER GROUND.
 
 
KANE
&

The office that day

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

IssuedProductOfficeCountiesLasted
Jan 9, 12:42 AM ESTFlash Flood WarningPBZBeaver3 hr
Jan 9, 2:17 AM ESTSevere Thunderstorm WarningPBZAllegheny58 min
Jan 9, 2:43 AM ESTSevere Thunderstorm WarningPBZWestmoreland32 min
Jan 9, 3:03 AM ESTSevere Thunderstorm WarningPBZArmstrong57 min
Jan 9, 3:28 AM ESTSevere Thunderstorm WarningPBZClarion62 min
Jan 9, 3:30 AM ESTFlash Flood WarningPBZClarion90 min
Jan 9, 3:51 AM ESTSevere Thunderstorm WarningPBZForest69 min

Nearby

Flash Flood Warnings in Pennsylvania, 1998Every flash flood warning in 1998

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; radar from the NEXRAD Level II archive.