Alert archive / Montana / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 21, NWS Missoula, MT

July 19, 1997Silver Bow County, Montana

NWS Missoula, MT issued this severe thunderstorm warning at Jul 19, 1997, 4:00 PM MDT for Silver Bow 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
Jul 19, 1997, 4:00 PM MDT (22:00 UTC)
Expired
Jul 19, 1997, 5:00 PM MDT
In force
60 min
Issued by
NWS Missoula, MT
Area
Whole counties

County Silver Bow County, MT

The radar

The Missoula radar (KMSX), 162 km from the middle of the area, began a volume at 22:03 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
Jul 19, 4:20 PM MDTHail 1Butte, 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 12:00Z, 10.0 hours before the alert went out and 234 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 1997-07-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 122 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Great_falls, MT at 12:00Z on 1997-07-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 44 square meters per square second.19395878Sfc1 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
122 J/kg
Mixed-layer CIN
-92 J/kg
Mixed-layer LCL
1225 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
44 m²/s²
0-3 km storm-relative helicity
51 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 192200 RRA
SVRMSO
MTC093-192300-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MISSOULA MT
400 PM MDT SAT JUL 19 1997
 
THE NATIONAL WEATHER SERVICE IN MISSOULA HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  500 PM MDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN SOUTHWEST MONTANA
 
   ...SILVER BOW COUNTY
 
AT 350 PM MDT RADAR INDICATED A SEVERE THUNDERSTORM 15 MILES SOUTH OF
BUTTE. THE STORM IS MOVING NORTH AT 20 MPH. THIS WILL PUT THE STORM NEAR
BUTTE BETWEEN 430 PM AND 445 PM MDT.
 
THIS STORM HAS A HISTORY OF PRODUCING FUNNEL CLOUDS...GOLF BALL SIZE HAI...AND HEAVY RAIN.
 
SEVERE THUNDERSTORMS PRODUCE DESTRUCTIVE HAIL...DEADLY LIGHTNING.X..
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.
 
WHITMORE
&

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 19, 8:30 AM MDTSevere Thunderstorm WarningMSOBeaverhead, Silver Bow60 min
Jul 19, 9:34 AM MDTSevere Thunderstorm WarningMSODeer Lodge56 min
Jul 19, 12:00 PM MDTSevere Thunderstorm WarningMSOPowell45 min
Jul 19, 2:19 PM MDTFlash Flood WarningMSOBeaverhead56 min
Jul 19, 2:19 PM MDTSevere Thunderstorm WarningMSOBeaverhead56 min
Jul 19, 3:06 PM MDTTornado WarningMSOBeaverhead69 min
Jul 19, 5:25 PM MDTSevere Thunderstorm WarningMSOPowell50 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.