Alert archive / Montana / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 14, NWS Missoula, MT

July 16, 1997Powell County, Montana

NWS Missoula, MT issued this severe thunderstorm warning at Jul 16, 1997, 11:00 PM MDT for Powell 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
Jul 16, 1997, 11:00 PM MDT (05:00 UTC)
Expired
Jul 16, 1997, 11:30 PM MDT
In force
30 min
Issued by
NWS Missoula, MT
Area
Whole counties

County Powell County, MT

The radar

The Missoula radar (KMSX), 82 km from the middle of the area, began a volume at 05:04 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

Great_falls, MT (KTFX), launched 00:00Z, 5.0 hours before the alert went out and 189 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 00:00Z on 1997-07-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 00:00Z on 1997-07-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 31 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
3076 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
31 m²/s²
0-3 km storm-relative helicity
119 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 170506 RRA
SVRMSO
MTC077-170530-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MISSOULA MT
1100 PM MDT WED JUL 16 1997
 
THE NATIONAL WEATHER SERVICE IN MISSOULA HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 1130 PM MDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN WEST CENTRAL MONTANA
 
   ...EAST CENTRAL POWELL COUNTY
 
RADAR INDICATES A STRONG THUNDERSTORM WAS LOCATED 5 MILES SOUTHWEST OF
AVON IN POWELL COUNTY. THIS STORM DOES CONTAIN THREE-QUARTER INCH SIZE
HAIL. THIS STORM WILL BE IN THE VICINITY OF AVON BY 1115 PM
MDT.
 
IF YOU ARE CAUGHT OUTSIDE...SEEK SHELTER FROM THE WEATHER IN A
STRONG BUILDING.  DAMAGING WIND...LARGE HAIL...VERY HEAV4Y 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 Jul 16, 8:16 PM MDT, 2 hours 44 minutes earlier.

Area forecast discussion, Jul 16, 8:16 PM MDT, 2 hours 44 minutes before
WESTERN MONTANA AND NORTH CENTRAL IDAHO FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
815 PM MDT WED JUL 16 1997

MSO GOES 9 SOUNDING AT 23Z SHOWS ETA MODEL A LITTLE TOO DRY AT MID
AND UPPER LEVELS. SATELLITE INDICATES HIGH-LEVEL TROPICAL MOISTURE
FROM ENRIQUE ADVANCING QUICKLY NORTHEASTWARD SPREADING OVER FORECAST
AREA. ISOLATED HIGH-BASED TSTMS STILL POSSIBLE ESPECIALLY SOUTHERN
MOUNTAINS AS INSTABILITY/GOOD THETA-E DIFFERENTIAL REMAINS OVERNIGHT.
WILL REWORD FORECAST OVER SOUTHERN ZONES AS MID/UPPER CLOUDS INCREASE
OVERNIGHT INTO THURSDAY. ALSO TEMPERATURES TOO LOW AS CLOUDS INCREASE
AND WARM ADVECTION CONTINUES. REQUEST UPDATE.

STOLL

LIB .. 055/081 048/077 ... 330332
FCA WW 053/080 046/075 044 330333
POL .. 058/084 051/079 ... 330443
MSO WW 055/087 049/080 047 330453
HMM .. 053/089 047/083 ... 331453
BTM .. 051/087 045/075 ... 331343
S80 .. 056/081 053/076 ... 330452
P69 .. 058/086 056/081 ... 331553
SMN .. 056/087 053/082 ... 331243

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; radar from the NEXRAD Level II archive.