Alert archive / Montana / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 50, NWS Missoula, MT

August 7, 1997Granite County, Missoula County, Powell County, Montana

NWS Missoula, MT issued this severe thunderstorm warning at Aug 7, 1997, 6:15 PM MDT for Granite County, Missoula County, Powell County, Montana. It was in force for 60 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued: Aug 7, 1997, 6:15 PM MDT (00:15 UTC)
Expired: Aug 7, 1997, 7:15 PM MDT
In force: 60 min
Issued by: NWS Missoula, MT
Area: Whole counties

Counties Granite County, MT, Missoula County, MT, Powell County, MT

The radar

The Missoula radar (KMSX), 52 km from the middle of the area, began a volume at 00:16 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.

What was reported inside it

Time	Report	Where	Remark
Aug 7, 7:00 PM MDT	Hail 1	Maxville, MT

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Great_falls, MT (KTFX), launched 00:00Z, 0.3 hours before the alert went out and 228 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 655 J/kg
Mixed-layer CIN: -41 J/kg
Mixed-layer LCL: 2423 m above ground
0-6 km bulk shear: 7 kt
0-1 km storm-relative helicity: -8 m²/s²
0-3 km storm-relative helicity: 72 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 080018 RRA
SVRMSO
MTC039-063-077-080115-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MISSOULA MT
615 PM MDT THU AUG 7 1997
 
THE NATIONAL WEATHER SERVICE IN MISSOULA HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  715 PM MDT
FOR PEOPLE IN THE FOLLOWING LOCATIONS...
 
IN WEST CENTRAL MONTANA
 
   ...GRANITE COUNTY...EASTERN MISSOULA COUNTY...POWELL COUNTY
 
AT 615 PM MDT...MISSOULA RADAR INDICATED SEVERAL SEVERE THUNDERSTORMS.
THE FIRST WAS IN NORTHERN POWELL COUNTY...18 MILES NORTHEAST OF SEELEY
LAKE. THE SECOND STORM WAS IN SOUTHEAST MISSOULA COUNTY...5 MILES WEST
OF POTOMAC. THE THIRD WAS 15 MILES WEST OF PHILIPSBURG IN GRANITE
COUNTY. ALL OF THESE STORMS WERE MOVING EAST AT 20 TO 25 MPH.
 
THESE STORMS HAVE HAD HISTORIES OF PRODUCING STRONG WINDS TO 60 MPH...
LARGE HAIL...HEAVY RAIN AND DEADLY LIGHTNING. IF YOU ARE CAUGHT OUTSIDE
...SEEK SHELTER FROM THE WEATHER IN A STRONG BUILDING. STAY INSIDE AWAY
FROM WINDOWS UNTIL THE STORMS HAVE PASSED.
 
THIS SEVERE THUNDERSTORM WARNING REPLACES THE WARNINGS ISSUED FOR
EASTERN GRANITE...SOUTHERN POWELL AND NORTHEAST MISSOULA COUNTIES.
 
BELTZ/CLEMMONS

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, 4 hours 30 minutes earlier.

Area forecast discussion, Aug 7, 1:45 PM MDT, 4 hours 30 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.

Issued	Product	Office	Counties	Lasted
Aug 7, 7:15 PM MDT	Severe Thunderstorm Warning	MSO	Granite, Powell	45 min
Aug 7, 8:00 PM MDT	Severe Thunderstorm Warning	MSO	Powell	45 min

Nearby

Severe Thunderstorm Warnings in Montana, 1997 Every 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.