Alert archive / Montana / Severe Thunderstorm Warnings in 1997
Severe Thunderstorm Warning 55, NWS Missoula, MT
NWS Missoula, MT issued this severe thunderstorm warning at Aug 20, 1997, 5:52 PM MDT for Granite County, Montana. It was in force for 68 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 20, 1997, 5:52 PM MDT (23:52 UTC)
- Expired
- Aug 20, 1997, 7:00 PM MDT
- In force
- 68 min
- Issued by
- NWS Missoula, MT
- Area
- Whole counties
County Granite County, MT
The nearest sounding before it
Great_falls, MT (KTFX), launched 12:00Z, 11.9 hours before the alert went out and 246 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1780 m above ground
- 0-6 km bulk shear
- 31 kt
- 0-1 km storm-relative helicity
- -8 m²/s²
- 0-3 km storm-relative helicity
- 108 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
646 WUUS1 KMSO 202353 RRA SVRMSO MTC039-210100- BULLETIN - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE MISSOULA MT 552 PM MDT WED AUG 20 1997 THE NATIONAL WEATHER SERVICE IN MISSOULA HAS ISSUED A SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 700 PM MDT FOR PEOPLE IN THE FOLLOWING LOCATION... IN WEST CENTRAL MONTANA ...NORTH CENTRAL GRANITE COUNTY AT 540 PM MDT WEATHER RADAR INDICATED A SEVERE THUNDERSTORM 12 MILE WEST OF MAXVILLE. THIS STORM WAS MOVING TO THE NORTHEAST AT 20 MPH AND IS EXPECTED TO MOVE INTO THE BEARMOUTH RECREATION AREA AROUND 615 PM. HAIL...STRONG GUSTY WINDS...BRIEF HEAVY RAIN AND FREQUENT LIGHTNING CAN BE EXPECTED WITH THIS THUNDERSTORM. WHEN THUNDERSTORMS ARE OCCURRING...PEOPLE SHOULD MOVE INSIDE A STRONG BUILDING. DO NOT STAND BY WINDOWS. DONT USE TELEPHONES OR ELECTRICAL APPLIANCES UNLESS IN AN EMERGENCY UNTIL THE STORM HAS PASSED. MOTORISTS SHOULD NOT DRIVE INTO LOW WATER CROSSINGS.
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 20, 1:55 PM MDT, 3 hours 57 minutes earlier.
Area forecast discussion, Aug 20, 1:55 PM MDT, 3 hours 57 minutes before
WESTERN MONTANA AND NORTH CENTRAL IDAHO FORECAST DISCUSSION NATIONAL WEATHER SERVICE MISSOULA MT 155 PM MDT WED AUG 20 1997 NGM ALREADY LOOKS BETTER THAN ETA OVER FASTER PROGRESSION OF LOW LEVEL MOISTURE AND SHORTWAVE IN OREGON...BUT EVEN IT IS TOO SLOW. CONVECTIVE CLOUDS ARE BEGINNING IN CENTRAL ID MOUNTAINS WHERE SUN HAS BEEN STRONG FOR AWHILE THOUGH NOTHING ON RADAR YET. VORT LOBE EXTENDING SOUTHEAST FROM LOW CENTER TOWARD SOUTHEAST OREGON CORNER IS MOVING NORTHEAST AND EXTRAPOLATION PLACES THE VORT AXIS NEAR MSO BY 00Z. NOT SURE ABOUT MUCH CONVECTION AFTER IT PASSES SO AM NOT KEEN ON HIGH POPS ANYWHERE TONIGHT EXCEPT NORTHWEST MT. DRY SOUTHWEST FLOW EXPECTED AFTER FIRST PERIOD AND WILL STICK WITH THE NIL MOS POPS. MID AND HIGH LEVEL CIRCULATION ASSOCIATED WITH THE EXTRATROPICAL LOW IS PERSISTENTLY STRONG AND WILL CONCEDE LIMITED COOL ADVECTION FROM IT FOR THU. WARMING UP AFTERWARD IN SOUTHWEST FLOW ON FRI BUT 93 FOR MSO LOOKS OVERDONE...AND 90 AT P69 UNDERDONE. GV ...FORECASTS BELOW ARE PRELIMINARY AND SUBJECT TO CHANGE... LIB .. 056/082 046/090 ... 356100 FCA UU 056/080 045/087 047 356000 POL .. 060/083 051/088 ... 356000 MSO UU 056/084 049/090 051 354000 HMM .. 057/086 048/092 ... 354000 BTM .. 046/083 042/087 ... 354000 S80 .. 054/084 050/088 ... 352000 P69 .. 059/088 054/093 ... 352000 SMN .. 057/085 051/090 ... 352000
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.