Alert archive / Washington / Severe Thunderstorm Warnings in 1991

Severe Thunderstorm Warning 2, NWS Spokane, WA

August 6, 19914 counties in Washington

NWS Spokane, WA issued this severe thunderstorm warning at Aug 6, 1991, 8:59 PM PDT for 4 counties in Washington. It was in force for 61 min.

The area

The counties it named.

The facts

Issued
Aug 6, 1991, 8:59 PM PDT (03:59 UTC)
Expired
Aug 6, 1991, 10:00 PM PDT
In force
61 min
Issued by
NWS Spokane, WA
Area
Whole counties

Counties Asotin County, WA, Columbia County, WA, Garfield County, WA, Whitman County, WA

The nearest sounding before it

Spokane Intl Airport, WA (KGEG), launched 00:00Z, 4.0 hours before the alert went out and 131 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, Spokane Intl Airport, WA at 00:00Z on 1991-08-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 477 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, Spokane Intl Airport, WA at 00:00Z on 1991-08-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 54 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
477 J/kg
Mixed-layer CIN
-35 J/kg
Mixed-layer LCL
1891 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
54 m²/s²
0-3 km storm-relative helicity
205 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.5

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KLWS 070359 RRA
SVRLWS
WAC003-013-023-075-070500-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE LEWISTON ID
859 PM PDT TUE AUG 6 1991
 
THE NATIONAL WEATHER SERVICE IN LEWISTON HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 1000 PM PDT
FOR PEOPLE IN THE FOLLOWING LOCATIONS......
 
IN EAST WASHINGTON
 
   ...ASOTIN COUNTY...COLUMBIA COUNTY...GARFIELD COUNTY...
AND WHITMAN COUNTY...
 
THE SEVERE THUNDERSTORM WARNING HAS BEEN EXTENDED UNTIL 10PM PDT AS
NEW CELLS HAVE FORMED SOUTHEAST OF WALLA WALLA AND ARE MOVING TO THE
NORTHEAST.
 
 
SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 55
MPH...DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAV

The office that day

Everything else NWS Spokane, WA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 6, 7:08 PM PDTSevere Thunderstorm WarningOTXAsotin, Columbia, Garfield, Whitman2 hr

Nearby

Severe Thunderstorm Warnings in Washington, 1991Every severe thunderstorm warning in 1991

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.