Alert archive / Montana / Severe Thunderstorm Warnings in 1997
Severe Thunderstorm Warning 71, NWS Missoula, MT
NWS Missoula, MT issued this severe thunderstorm warning at Sep 15, 1997, 10:50 AM MDT for Granite County, Powell County, Montana. It was in force for 40 min. 2 reports 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
- Sep 15, 1997, 10:50 AM MDT (16:50 UTC)
- Expired
- Sep 15, 1997, 11:30 AM MDT
- In force
- 40 min
- Issued by
- NWS Missoula, MT
- Area
- Whole counties
Counties Granite County, MT, Powell County, MT
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Sep 15, 11:00 AM MDT | Thunderstorm Wind 60 | Philipsburg, MT | |
| Sep 15, 11:17 AM MDT | Hail 0.75 | Helmville, 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, 4.8 hours before the alert went out and 217 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
- 54 J/kg
- Mixed-layer CIN
- -492 J/kg
- Mixed-layer LCL
- 1231 m above ground
- 0-6 km bulk shear
- 37 kt
- 0-1 km storm-relative helicity
- 156 m²/s²
- 0-3 km storm-relative helicity
- 181 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.0
The text
As transmitted, in the capitals the NWS used until 2016.
000 TTAA00 KMSO 151651 RRA SVRMSO MTC039-077-151730- BULLETIN - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE MISSOULA MT 1050 AM MDT MON SEP 15 1997 THE NATIONAL WEATHER SERVICE IN MISSOULA HAS ISSUED A SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 1130 AM MDT FOR PEOPLE IN THE FOLLOWING LOCATIONS... IN WEST CENTRAL MONTANA ...EASTERN GRANITE COUNTY...SOUTHERN POWELL COUNTY AT 1050 AM MDT A SEVERE THUNDERSTORM WAS DETECTED IN EASTERN GRANITE COUNTY 10 MILES SOUTHWEST OF DRUMMOND. THE STORM IS MOVING TO THE NORTHEAST AT 35 MPH AND WILL APPROACH DRUMMOND JUST AFTER 11 AM. THIS STORM WILL MOVE ACROSS SOUTHERN POWELL COUNTY. 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. WHITMORE
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 Sep 15, 9:15 AM MDT, 1 hour 35 minutes earlier.
Area forecast discussion, Sep 15, 9:15 AM MDT, 1 hour 35 minutes before
WESTERN MONTANA AND NORTH CENTRAL IDAHO FORECAST DISCUSSION NATIONAL WEATHER SERVICE MISSOULA MT 915 AM MDT MON SEP 15 1997 TROF OFF THE PAC NW COAST WITH NUMEROUS SHORTWAVES RIPPLING AROUND. COLD FRONT MOVED THROUGH WRN MT OVERNIGHT AND ASSOCIATED SHOWER BAND IS MOVING NORTHEAST AND WILL BE OUT OF THE AREA THIS MORNING. MORE WIDESPREAD AREA OF SHOWERS BEHIND ASSOCIATED WITH UPPER LEVEL FEATURES. NEW ETA HAS TROF MOVING THROUGH AREAA OVERNIGHT AND WEAK RIDGE FOR TUESDAY. THICKNESS DROPS TO BELOW 549 MOST OF AREA TONIGHT AND MENTION OF SNOW IN HIGHER ELEVATIONS REASONABLE. HIGH RH/CLOUDS SHOULD KEEP FROST FROM BEING A CONCERN. CURRENT FORECASTS APPEAR TO BE ON TRACK. NO UPDATES PLANNED. HOADLEY ...FORECASTS BELOW ARE PRELIMINARY AND SUBJECT TO CHANGE... LIB .. 061/045 060/... ... 40744 FCA WE 062/044 058/040 060 40744 POL .. 063/050 060/... ... 40643 MSO WE 065/046 060/042 063 40643 HMM .. 066/044 062/... ... 40643 BTM .. 065/044 056/... ... 40553 S80 .. 064/047 060/... ... 40743 P69 .. 066/052 063/... ... 40753 SMN .. 066/044 063/... ... 40652
The office that day
Everything else NWS Missoula, MT issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 14, 9:30 PM MDT | Severe Thunderstorm Warning | MSO | Flathead | 45 min |
| Sep 15, 5:41 AM MDT | Severe Thunderstorm Warning | MSO | Missoula | 64 min |
| Sep 15, 10:40 AM MDT | Severe Thunderstorm Warning | MSO | Missoula, Powell | 60 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.