Alert archive / Montana / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 28, NWS Missoula, MT

August 1, 1997Flathead County, Montana

NWS Missoula, MT issued this severe thunderstorm warning at Aug 1, 1997, 7:20 PM MDT for Flathead County, Montana. It was in force for 40 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 1, 1997, 7:20 PM MDT (01:20 UTC)
Expired
Aug 1, 1997, 8:00 PM MDT
In force
40 min
Issued by
NWS Missoula, MT
Area
Whole counties

County Flathead County, MT

The radar

The Missoula radar (KMSX), 140 km from the middle of the area, began a volume at 01:24 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

TimeReportWhereRemark
Aug 1, 7:25 PM MDTHail 1.5Kalispell, 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

Spokane, WA (KOTX), launched 00:00Z, 1.3 hours before the alert went out and 187 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 00:00Z on 1997-08-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 751 joules per kilogram.LCLEL10008507005003002001001 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 00:00Z on 1997-08-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 11 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
751 J/kg
Mixed-layer CIN
-12 J/kg
Mixed-layer LCL
2471 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
11 m²/s²
0-3 km storm-relative helicity
87 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 020121 RRA
SVRMSO
MTC029-020200-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MISSOULA MT
720 PM MDT FRI AUG 1 1997
 
THE NATIONAL WEATHER SERVICE IN MISSOULA HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  800 PM MDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN NORTHWEST MONTANA
 
   ...SOUTHERN FLATHEAD COUNTY
 
AT 715 PM MDT MISSOULA DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM 12
MILES SOUTHWEST OF KALISPELL...APPROACHING HIGHWAY 2 AT SMITH LAKE. IT
WILL PASS OVER HIGHWAY 93 4 MILES SOUTH OF KALISPELL ABOUT 745 PM.
 
SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 55
MPH...DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN..
FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR
OF YOUR HOME OR BUSINESS.  HEAVY RAINS FLOOD ROADS QUICKLY SO
DON'T DRIVE INTO AREAS WHERE WATER COVERS THE ROAD.
GV/PF

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 1, 1:55 PM MDT, 5 hours 25 minutes earlier.

Area forecast discussion, Aug 1, 1:55 PM MDT, 5 hours 25 minutes before
WESTERN MONTANA AND NORTH CENTRAL IDAHO FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
145 PM MDT FRI AUG 1 1997

CONVECTION DEVELOPING IN CONVERGENT BAND OVER SOUTHERN IDAHO COUNTY
AND LEMHI COUNTY...A FEW TSTMS ALREADY APPROACHING STRONG ATTM IN
LEMHI COUNTY. SOUNDER LI.S SHOWING -3 TO -7 IN AREAS OF CLEAR SKIES
WEST CENTRAL...NORTHWEST MONTANA AND NORTHERN IDAHO PANHANDLE. S/WV
TROUGH IN NORTHERN CALIFORNIA FCST BY NGM/ETA TO MOVE INTO FCST AREA
OVERNIGHT AND WILL ENHANCE CONVERGENT BOUNDARY. S/WV TO STRENGTHEN
DUE TO RIDGING FROM THE WEST AS NEXT PACIFIC SYSTEM APPROACHES THE
COAST...SO NGM AND ETA MORE BELIEVABLE THAN AVN. LOW DEVELOPS
OVERNIGHT IN SOUTHERN IDAHO COUNTY ALONG SOUTHWEST TO NORTHEAST
TROUGH WHICH EXTENDS UP INTO NORTHWEST MONTANA. CAPES REMAIN HIGH
TONIGHT BETWEEN 700 TO 800 J/KG. GOOD 3H DIVERGENCE OVER NORTHERN
IDAHO AND NORTHWEST MONTANA TONIGHT TO AID IN LIFTING...SO SOME
STRONG TSTMS THIS EVENING WITH THUNDERSTORM LINGERING INTO THE
MORNING...MAINLY WESTERN MONTANA.
SATURDAY...
UPPER LEVEL SYSTEM MOVES EAST OF THE DIVIDE WITH SFC TROUGH MOVING
DOWN INTO SOUTHWEST MONTANA AND SOUTHERN LEMHI COUNTY...WHERE POPS
ARE HIGHER. SLIGHTLY COOLER TEMPS AND DRYING LATER IN THE AFTERNOON.
SUNDAY...
RIDGE OF HIGH PRESSURE RETROGRADES WEST ENOUGH FOR DRIER AND MORE
STABLE. AVN INDICATING A WEAK S/WV APPROACHING FROM THE WEST
SUNDAY...HOWEVER TO DRY AND STABLE FOR MUCH OF ANY THING.
TC
...FORECASTS BELOW ARE PRELIMINARY AND SUBJECT TO CHANGE...

LIB .. 054/084 054/087 ... 294321
FCA BU 052/084 052/086 054 29542-
POL .. 058/085 058/088 ... 29532-
MSO BU 055/087 053/090 056 29532-
HMM .. 053/089 051/092 ... 29532-
BTM .. 051/086 049/089 ... 29433-
S80 .. 057/084 059/088 ... 295211
P69 .. 059/086 061/090 ... 295211
SMN .. 052/084 054/088 ... 294210

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 2, 3:01 PM MDTSevere Thunderstorm WarningMSOBeaverhead29 min
Aug 2, 3:28 PM MDTSevere Thunderstorm WarningMSOBeaverhead47 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.