Alert archive / Montana / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 42, NWS Missoula, MT

August 7, 1997Beaverhead County, Deer Lodge County, Ravalli County, Montana

NWS Missoula, MT issued this severe thunderstorm warning at Aug 7, 1997, 3:30 PM MDT for Beaverhead County, Deer Lodge County, Ravalli County, Montana. It was in force for 30 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Aug 7, 1997, 3:30 PM MDT (21:30 UTC)
Expired
Aug 7, 1997, 4:00 PM MDT
In force
30 min
Issued by
NWS Missoula, MT
Area
Whole counties

Counties Beaverhead County, MT, Deer Lodge County, MT, Ravalli County, MT

The nearest sounding before it

Great_falls, MT (KTFX), launched 12:00Z, 9.5 hours before the alert went out and 283 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, Great_falls, MT at 12:00Z on 1997-08-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 151 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, Great_falls, MT at 12:00Z on 1997-08-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 92 square meters per square second.1939Sfc1 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
151 J/kg
Mixed-layer CIN
-192 J/kg
Mixed-layer LCL
2429 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
92 m²/s²
0-3 km storm-relative helicity
70 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KMSO 072136 RRA
SVRMSO
MTC001-023-081-072200-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MISSOULA MT
330 PM MDT THU AUG 7 1997
 
THE NATIONAL WEATHER SERVICE IN MISSOULA HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  400 PM MDT
FOR PEOPLE IN THE FOLLOWING LOCATIONS...
 
IN SOUTHWEST MONTANA
 
   ...NORTHERN BEAVERHEAD COUNTY...WESTERN DEER LODGE COUNTY
 
IN WEST CENTRAL MONTANA
 
   ...SOUTHERN RAVALLI COUNTY
 
WEATHER SERVICE RADAR INDICATES STRONG THUNDERSTORMS 10 MILES EAST OF
SULA MOVING EAST AT 20 MPH.
 
 
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.

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Missoula, MT wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 7, 1:45 PM MDT, 1 hour 45 minutes earlier.

Area forecast discussion, Aug 7, 1:45 PM MDT, 1 hour 45 minutes before
WESTERN MONTANA AND NORTH CENTRAL IDAHO FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
145 PM MDT THU AUG 7 1997

SFC FRONT STILL EXTENDS FROM EXTREME NORTHWEST MT TO SOUTHEAST WA.
ISOLATED TSTMS IN PANHANDLE AND NORTHWEST MONTANA WITH FIRST WARNING
JUST ISSUED FOR STORM NEAR FCA. BUILDUPS STILL OCCURRING AHEAD OF
FRONT OVER CENTRAL ID/SOUTHWEST MT SO NOT OUT OF WOODS YET IN THESE
AREAS SINCE FRONT/ASSOCIATED SHORTWAVE STILL YET TO PUSH EAST...WHICH
SHOULD TRIGGER SCATTERED TSTMS IN THESE AREAS BY LATE AFTERNOON DUE
TO VERY UNSTABLE ATMOSPHERE. BECOMING COOL AND DRY BEHIND FRONT BUT
CHANNELED VORT WITH SOME MOISTURE WORKING THROUGH WEST MONTANA LATER
FRIDAY INTO SATURDAY. DYNAMICS LACKING SO MAY ONLY MENTION ISOLATED
SHOWERS OVER THE NORTHERN MOUNTAINS. BELTZ

...FORECASTS BELOW ARE PRELIMINARY AND SUBJECT TO CHANGE...
LIB .. 047/074 045/073 ... 2710-1
FCA BB 049/075 046/073 046 2710-1
POL .. 053/077 051/075 ... 271001
MSO BB 052/080 048/078 048 27200-
HMM .. 049/082 046/080 ... 272000
BTM .. 048/080 045/077 ... 273000
S80 .. 056/081 051/080 ... 271000
P69 .. 058/083 053/082 ... 272000
SMN .. 050/083 047/082 ... 272000

The office that day

Everything else NWS Missoula, MT issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 7, 1:35 PM MDTSevere Thunderstorm WarningMSOFlathead40 min
Aug 7, 2:00 PM MDTSevere Thunderstorm WarningMSOMissoula60 min
Aug 7, 2:15 PM MDTSevere Thunderstorm WarningMSOFlathead60 min
Aug 7, 2:20 PM MDTSevere Thunderstorm WarningMSOMissoula55 min
Aug 7, 3:00 PM MDTSevere Thunderstorm WarningMSOPowell60 min
Aug 7, 3:55 PM MDTSevere Thunderstorm WarningMSOLake35 min
Aug 7, 4:00 PM MDTSevere Thunderstorm WarningMSOPowell45 min
Aug 7, 4:30 PM MDTSevere Thunderstorm WarningMSOFlathead45 min
Aug 7, 4:43 PM MDTSevere Thunderstorm WarningMSOSanders47 min
Aug 7, 5:16 PM MDTSevere Thunderstorm WarningMSOBeaverhead59 min
Aug 7, 5:35 PM MDTSevere Thunderstorm WarningMSOGranite, Missoula, Powell55 min
Aug 7, 5:35 PM MDTSevere Thunderstorm WarningMSOLake55 min

Nearby

Severe Thunderstorm Warnings in Montana, 1997Every severe thunderstorm warning in 1997

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.