Alert archive / Idaho / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 41, NWS Missoula, MT

August 7, 1997Lemhi County, Idaho

NWS Missoula, MT issued this severe thunderstorm warning at Aug 7, 1997, 3:21 PM MDT for Lemhi County, Idaho. It was in force for 69 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, 3:21 PM MDT (21:21 UTC)
Expired
Aug 7, 1997, 4:30 PM MDT
In force
69 min
Issued by
NWS Missoula, MT
Area
Whole counties

County Lemhi County, ID

The radar

The Pocatello radar (KSFX), 227 km from the middle of the area, began a volume at 21:20 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

Spokane, WA (KOTX), launched 12:00Z, 9.4 hours before the alert went out and 360 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, WA at 12:00Z on 1997-08-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 45 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, WA at 12:00Z on 1997-08-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -3 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
45 J/kg
Mixed-layer CIN
-382 J/kg
Mixed-layer LCL
1987 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
-3 m²/s²
0-3 km storm-relative helicity
85 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KMSO 072126 RRA
SVRMSO
IDC059-072230-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MISSOULA MT
321 PM MDT (221 PM PDT) THU AUG 7 1997
 
THE NATIONAL WEATHER SERVICE IN MISSOULA HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  430 PM MDT (330 PM PDT)
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN CENTRAL IDAHO
 
   ...NORTHERN LEMHI COUNTY
 
RADAR INDICATES A SEVERE THUNDERSTORM 25 MILES WEST-SOUTHWEST OF
GIBBONSVILLE IN LEMHI COUNTY. THIS STORM WILL PASS NEAR GIBBONSVILLE BY
430 PM MDT. BRIEF HEAVY RAIN..AND HAIL SHOULD BE EXPECTED WITH THIS
STORM.
 
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 36 minutes earlier.

Area forecast discussion, Aug 7, 1:45 PM MDT, 1 hour 36 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

Nearby

Severe Thunderstorm Warnings in Idaho, 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; radar from the NEXRAD Level II archive.