Thunderstorm Wind, Granite
- When
- August 31, 5:50 PM MST to 6:00 PM MST
- Where
- Granite County, 18 mi NW of Hall
- Measured
- 54 kt (62 mph) estimated gust
- Reported by
- UTILITY COMPANY
- Coordinates
- 46.600, -113.467
Damaging Winds in Montana, August 31, 2004
Thunderstorm wind damage occurred during the evening hours in western Granite and central Powell Counties. Powell County Sheriff reported power poles blown over onto Highway 200 near the Ovando area with power outages.
Where it happened
Every event with a place to put it. Tap one for its entry below.
- Tornadoes
- Tropical storms and surge
- Floods
- Wind
- Hail
- Winter weather
- Heat and drought
- Cold
- Fire, smoke and dust
- Marine and coastal
- Other
The toll
- Deaths
- 0
- Injuries
- 0
- Property damage
- None recorded
- Crop damage
- None recorded
- Events
- 2
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
What happened
The episode as NWS MSO wrote it up.
Thunderstorm wind damage occurred during the evening hours in western Granite and central Powell Counties. Powell County Sheriff reported power poles blown over onto Highway 200 near the Ovando area with power outages. Power Company in Granite County reported two downed trees onto power lines with power outages up Rock Creek.
What forecasters said that day
The local office's own words before the first event, 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 the first event at Aug 31, 5:16 PM MST, 34 minutes earlier.
Area forecast discussion, Aug 31, 5:16 PM MST, 34 minutes before
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MISSOULA MT 616 PM MDT TUE AUG 31 2004 .UPDATE...WILL UPDATE THE FORECAST TONIGHT TO INCLUDE THUNDER AND SHOWERS FOR THE MOST OF THE FORECAST AREA. THE EXCEPTIONS WILL BE LEMHI COUNTY IDAHO AND THE FLATHEAD...MISSOULA...AND BITTERROOT VALLEYS IN MONTANA. MIXING HAS BEGUN LATE TODAY...KEEPING TEMPERATURES COOLER AT LOWER ELEVATIONS THAN PREVIOUSLY EXPECTED. INVERTED LAYERS HAVE BEGUN TO BREAK LATE THIS AFTERNOON...ALLOWING SHOWERS AND THUNDERSTORMS TO DEVELOP. STORMS ARE CURRENTLY MAINLY OVER THE BITTERROOT AND CLEARWATER MOUNTAINS. MOST OF THESE THUNDERSTORMS ARE HIGH BASED AND PRODUCING LITTLE PRECIPITATION...SO WILL KEEP POPS LOW. && .PREVIOUS DISCUSSION...TONIGHT THROUGH FRIDAY...RIDGE CONTINUES ACROSS THE FORECAST AREA TONIGHT...BUT WITH THE TROUGH DIGGING DOWN THE PACIFIC COAST...THE RIDGE IS STARTING THE FLATTEN AND SHIFT TO THE EAST. A WEAK DISTURBANCE IS MOVING FROM THE SOUTHWEST AND PRODUCING SOME SHOWERS OVER EASTERN WASHINGTON AND NORTHERN IDAHO. THESE SHOWERS WILL JUST CATCH THE EXTREME NORTHWESTERN CORNER OF THE FORECAST AREA THIS EVENING. LATER TONIGHT AND EARLY WEDNESDAY THE TROUGH WILL CONTINUE TO SLIDE TO THE EAST AND PUSH SOME MORE WEAK DISTURBANCES INTO THE REGION...WILL KEEP SOME LOW POPS ACROSS MAINLY THE WESTERN HALF OF THE FORECAST AREA THROUGH MORNING...WARM AND UNSTABLE AIR WILL MOVE INTO THE REGION AHEAD OF THE COLD FRONT. WEDNESDAY AFTERNOON AS THE COLD FRONT MOVES ACROSS WASHINGTON AND INTO THE IDAHO PANHANDLE THE ATMOSPHERE GETS MORE UNSTABLE WITH THUNDERSTORMS DEVELOPING...SOME EARLY STORMS COULD HAVE GUSTY WINDS WITH THEM. ALSO WITH A TIGHTENING SURFACE PRESSURE GRADIENT OVER THE REGION...WILL SEE AN INCREASE IN SURFACE WINDS. WIND SPEED COULD REACH LAKE WIND ADVISORY CRITERIA DURING THE AFTERNOON...WILL LEAVE THIS FOR THE NEXT FORECAST PACKAGE TO TAKE A CLOSER LOOK AT. WEDNESDAY NIGHT THE COLD FRONT MOVES ACROSS WESTERN MONTANA...WITH SHOWERS AND WINDS DECREASING BEHIND THE FRONT. COOLER CONDITIONS WITH ANOTHER WEAK DISTURBANCE ROTATING IN FROM THE NORTH WILL BE THE RULE ON THURSDAY AND THURSDAY NIGHT. BY FRIDAY THE TROUGH HAS MOVED OFF TO THE EAST WITH HIGH PRESSURE BEGINNING TO REBUILD INTO THE AREA. FRIDAY NIGHT THROUGH TUESDAY NIGHT...A RIDGE OF HIGH PRESSURE CONTINUES TO BUILD ALONG THE WEST COAST FRIDAY NIGHT AND SATURDAY. THIS RIDGE WILL DRAG IN WARMER AND DRIER AIR INTO THE REGION. THERE ARE A FEW WEAK SHORTWAVES EMBEDDED IN THE NORTHWEST FLOW...SO KEPT A SLIGHT CHANCE OF SHOWERS ALONG THE CONTINENTAL DIVIDE FOR FRIDAY NIGHT AND SATURDAY NIGHT. THEN THE RIDGE GETS PUSHED TO THE SOUTHEAST A BIT...PUTTING WESTERN MONTANA AND NORTH CENTRAL IDAHO IN WESTERLY FLOW FOR THE REMAINDER OF THE FORECAST PERIOD. THIS ZONAL FLOW WILL CAUSE THE AREA TO HAVE MILD TEMPERATURES. WILL HAVE TO KEEP WATCH OF WEAK SHORTWAVES MOVING THROUGH THE THIS ZONAL FLOW FOR CHANCES OF PRECIP THROUGHOUT NEXT WEEK...BUT HAVE KEPT THE FORECAST DRY AT THIS TIME. && .MSO WATCHES/WARNINGS/ADVISORIES... MT...NONE. ID...NONE. && UPDATE/STEGEMILLER PREVIOUS/KOLATA/SMITH/WHITMORE
Hazardous weather outlook, Aug 31, 2:00 PM MST, 3 hours 50 minutes before
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE MISSOULA MT 300 PM MDT (200 PM PDT) TUE AUG 31 2004 MTZ001>004-043-011300- KOOTENAI/CABINET REGION-WEST GLACIER REGION-FLATHEAD/MISSION VALLEYS- LOWER CLARK FORK REGION-BLACKFOOT REGION- 300 PM MDT TUE AUG 31 2004 THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH CENTRAL IDAHO AND WESTERN MONTANA .DAY ONE... REST OF TODAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN... WEDNESDAY THROUGH MONDAY A PACIFIC WEATHER SYSTEM WILL MOVE INTO WESTERN MONTANA WEDNESDAY AFTERNOON. THE SURFACE PRESSURE GRADIENT WILL TIGHTEN AHEAD OF AND WITH THIS FRONT INCREASING THE WIND SPEEDS. A LAKE WIND ADVISORY MAY NEED TO BE ISSUED WEDNESDAY MORNING. ALONG WITH THE WINDS... THUNDERSTORMS AND COOLER TEMPERATURES CAN BE EXPECTED. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. IDZ005>008-011300- NORTHERN CLEARWATER MOUNTAINS-SOUTHERN CLEARWATER MOUNTAINS- OROFINO/GRANGEVILLE REGION-LOWER HELLS CANYON/SALMON RIVER- 200 PM PDT TUE AUG 31 2004 THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH CENTRAL IDAHO AND WESTERN MONTANA .DAY ONE... REST OF TODAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN... WEDNESDAY THROUGH MONDAY A PACIFIC WEATHER SYSTEM WILL MOVE INTO NORTHERN IDAHO ON WEDNESDAY. THIS SYSTEM WILL BRING GUSTY WINDS AND THUNDERSTORMS INTO THE AREA. SOME OF THE FIRST THUNDERSTORMS COULD HAVE STRONG DOWNBURST WINDS ASSOCIATED WITH THEM. COOLER TEMPERATURES WILL MOVE INTO THE REGION BY WEDNESDAY NIGHT. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. IDZ009-010-MTZ005>007-011300- WESTERN LEMHI COUNTY-EASTERN LEMHI COUNTY- MISSOULA/BITTERROOT VALLEYS-BITTERROOT/SAPPHIRE MOUNTAINS- BUTTE/PINTLAR REGION- 300 PM MDT TUE AUG 31 2004 THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH CENTRAL IDAHO AND WESTERN MONTANA .DAY ONE... REST OF TODAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN... WEDNESDAY THROUGH MONDAY A PACIFIC WEATHER SYSTEM WILL MOVE ACROSS WESTERN MONTANA AND IDAHO ON WEDNESDAY. THIS SYSTEM WILL BRING GUSTY WINDS AND THUNDERSTORMS INTO THE AREA BY WEDNESDAY AFTERNOON. COOLER TEMPERATURES WILL MOVE INTO THE REGION ON THURSDAY. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.
The radar
The Missoula radar (KMSX), 63 km away, was scanning. The volume nearest the first event began at 00:48 UTC.
Event by event
2 thunderstorm wind. Local standard time, as filed.
Thunderstorm Wind, Powell
- When
- August 31, 6:20 PM MST
- Where
- Powell County, Ovando
- Measured
- 55 kt (63 mph) estimated gust
- Reported by
- LAW ENFORCEMENT
- Coordinates
- 47.017, -113.133
What these are
- Thunderstorm Wind
- Winds from a thunderstorm of 50 knots (58 mph) or more, or lower winds that caused damage or casualties. Measured gusts are marked MG, estimated EG.
After NWS Directive 10-1605, the rules offices file Storm Data by.
The same day elsewhere
- Flash Flooding in Texas, August 31, 2004
- Hail in Nebraska, August 31, 2004
- Flash Flooding in Texas, August 31, 2004
- Hail in Colorado, August 31, 2004
- Damaging Wind in Nebraska, August 31, 2004
- Flash Flood in New Jersey, August 31, 2004
- Flash Flood in Texas, August 31, 2004
- Lightning Strike in South Dakota, August 31, 2004
- Damaging Wind in Florida, August 31, 2004
- Lightning Strike in Florida, August 31, 2004
- Damaging Wind in Georgia, August 31, 2004
- Funnel Cloud in Florida, August 31, 2004
More
Every storm in Montana in 2004Every state in 2004This day in weather historyWarnings in Montana, August 2004
Sources
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 5420033, 5420032.