On July 17, a strong short wave trough moved to the northeast across West Central Montana during the evening hours. Isolated severe thunderstorms were able to mix down upper level winds to create isolated wind damage in both Lake and Sanders Counties.
Every event with a place to put it. Tap one for its entry below.
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.
The episode as NWS MSO wrote it up.
On July 17, a strong short wave trough moved to the northeast across West Central Montana during the evening hours. Isolated severe thunderstorms were able to mix down upper level winds to create isolated wind damage in both Lake and Sanders Counties.
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 Jul 17, 2:29 AM MST, 4 hours 55 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MISSOULA MT 329 AM MDT TUE JUL 17 2007 .DISCUSSION...A DEEP LOW PRESSURE SYSTEM DRIFTING CLOSER TO THE OREGON COAST HAS BEGUN TO PUMP SUB-TROPICAL MOISTURE NORTHWARD TOWARDS THE NORTHERN ROCKIES REGION. SATELLITE IMAGERY CLEARLY SHOWS A DISTURBANCE MAKING ITS WAY NORTH THROUGH NORTHEAST NEVADA/SOUTHERN IDAHO EARLY THIS MORNING. THE AIR MASS REMAINS WARM AND UNSTABLE WITH THE BIGGEST CHANGE FOCUSED AROUND INCREASED MOISTURE...EXPANDING THE SHOWER/THUNDERSTORM POTENTIAL THROUGHOUT NORTH-CENTRAL IDAHO AND WESTERN MONTANA. INCREASED CLOUD COVER AND SHOWERS WILL HELP HOLD TEMPERATURES DOWN IN INTO THE UPPER 80S AND 90S IN MOST LOCATIONS. NORTHWEST MONTANA WILL SEE SOME OF THE WARMER TEMPERATURES DUE TO THE LATER ARRIVAL OF CLOUDS AND SHOWERS. CONVECTION WILL CONTINUE INTO THE EVENING HOURS BEFORE TAPERING OFF AFTER MIDNIGHT. WEDNESDAY AND WEDNESDAY NIGHT...THE MODELS HAVE BEEN CONSISTENT WILL THE STRENGTHENING OF THE UPPER RIDGE AND MIGRATION OF DRIER AIR INTO THE AREA FROM THE SOUTH. SKIES ARE EXPECTED TO CLEAR BY MORNING. THE AIR MASS WILL REMAIN VERY WARM AND QUITE UNSTABLE. THUS...AFTERNOON BUILDUPS AND ISOLATED LATE-DAY THUNDERSTORMS ARE STILL IN THE FORECAST PICTURE...MAINLY ALONG THE CONTINENTAL DIVIDE AND NORTHWEST MONTANA. THURSDAY...THE AFOREMENTIONED LOW SYSTEM OFF THE OREGON COAST WILL KICK INLAND OVER THE PACIFIC NORTHWEST AS AN OPEN TROUGH AND SWEEP NORTHWARD BRUSHING BY OUR WESTERN ZONES. THIS WILL EFFECTIVELY SHOVE THE INVERTED SURFACE TROUGH ACROSS WESTERN MONTANA LATER IN THE DAY. THE COMBINATION OF WINDS ALOFT MIXING THE SURFACE AND AN INCREASED SURFACE PRESSURE GRADIENT WILL RESULT IN INCREASED WINDS. WINDS COUPLED WITH EXISTING HOT DRY CONDITIONS WILL RAISE FIRE WEATHER CONCERNS...ESPECIALLY AFTER A CONVECTIVELY ACTIVE PERIOD. THURSDAY NIGHT THROUGH MONDAY...AS THE SYSTEM MOVES QUICKLY TO THE NORTH INTO CANADA A STRONG SURFACE PRESSURE GRADIENT WILL KEEP BREEZY CONDITIONS INTO THE EVENING HOURS THURSDAY. THE HIGH PRESSURE RIDGE WILL BEGIN TO PUSH BACK TO THE NORTH AND ALLOW FOR ANOTHER WARMING TREND THROUGH THE WEEKEND. TEMPERATURES ARE EXPECTED TO BE NEAR THE CENTURY MARK AGAIN ON SATURDAY AND SUNDAY. FRIDAY SHOULD BE MOSTLY SUNNY AND DRY. ON SATURDAY A WAVE OF ENERGY WILL PASS THROUGH AND COUPLED WITH A RELATIVE INCREASE IN MOISTURE WILL BRING CHANCES FOR SHOWERS AND THUNDERSTORMS PARTICULARLY ALONG THE CONTINENTAL DIVIDE DURING THE AFTERNOON. A SIMILAR SETUP WILL FORM ON SUNDAY AND MONDAY AFTERNOONS AS WELL AND SLIGHT CHANCES FOR THUNDERSTORMS ARE EXPECTED AGAIN ALONG THE DIVIDE. && .AVIATION...WIDELY SCATTERED SHOWERS CONTINUE IN SOUTHWEST MONTANA THIS MORNING BUT WILL BE MOVING OUT OF THE AREA SHORTLY AFTER SUNRISE. AIRCRAFT FLYING THROUGH THIS AREA AND AROUND THE KBTM TERMINAL SHOULD BE AWARE OF POTENTIAL GUSTY WINDS ASSOCIATED WITH THESE STORM CELLS THIS MORNING. THIS AFTERNOON ANOTHER STORM SYSTEM PUSHES THROUGH AND WILL CAUSE WIDESPREAD CONVECTION WITH ELEVATED POTENTIAL FOR GUSTY WINDS AND TURBULENCE LATE MORNING THROUGH THIS EVENING THROUGHOUT WESTERN MONTANA AND NORTH CENTRAL IDAHO...SEE APPROPRIATE TAFS AND TWEBS. && .FIRE WEATHER...THUNDERSTORMS ACTIVITY WILL INCREASE TODAY AS WELL EXPAND INTO NORTHWEST MONTANA. THE AIR MASS IS EXPECTED TO DRY AND WARM...THUS RETURNING TEMPERATURE READINGS BACK TOWARDS NEAR RECORD LEVELS ON WEDNESDAY. THURSDAY...THERE IS A GROWING CONCERN THAT A COMBINATION OF INCREASED WINDS...HOT DRY CONDITIONS AND EVEN A POTENTIAL OF ISOLATED LATE AFTERNOON THUNDERSTORMS WILL PROVIDE AN ACTIVE BURNING PERIOD. && .MSO WATCHES/WARNINGS/ADVISORIES... MT...NONE. ID...NONE. && SHORT TERM...MSJ LONG TERM....FOSTER AVIATION...FOSTER
HAZARDOUS WEATHER OUTLOOK...CORRECTED NATIONAL WEATHER SERVICE MISSOULA MT 606 AM MDT TUE JUL 17 2007 IDZ005>010-MTZ001>007-043-180030- NORTHERN CLEARWATER MOUNTAINS-SOUTHERN CLEARWATER MOUNTAINS- OROFINO/GRANGEVILLE REGION-LOWER HELLS CANYON/SALMON RIVER REGION- WESTERN LEMHI COUNTY-EASTERN LEMHI COUNTY-KOOTENAI/CABINET REGION- WEST GLACIER REGION-FLATHEAD/MISSION VALLEYS- LOWER CLARK FORK REGION-MISSOULA/BITTERROOT VALLEYS- BITTERROOT/SAPPHIRE MOUNTAINS-BUTTE/BLACKFOOT REGION- POTOMAC/SEELEY LAKE REGION- 606 AM MDT TUE JUL 17 2007 /506 AM PDT TUE JUL 17 2007/ THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH CENTRAL IDAHO...NORTHWEST MONTANA AND WEST CENTRAL MONTANA. .DAY ONE...TODAY AND TONIGHT SCATTERED THUNDERSTORMS WILL DEVELOP AND MOVE NORTH THROUGH NORTH- CENTRAL IDAHO AND WESTERN MONTANA. A FEW OF THESE STORMS MAY BECOME STRONG PRODUCING WIND GUSTS UP TO 40 MPH AND BRIEF HEAVY RAIN. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY WEDNESDAY...THE AIR MASS WILL HEAT UP AND DESTABILIZE ONCE AGAIN WITH SOME THUNDERSTORMS DEVELOPING LATE ACROSS WESTERN MONTANA. WIND GUSTS UP TO 40 MPH AND SMALL HAIL ARE POSSIBLE WITH FEW STORMS NEAR THE CANADIAN BORDER. THURSDAY...A COMBINATION OF INCREASED WINDS...HOT DRY CONDITIONS AND EVEN A POTENTIAL OF ISOLATED LATE AFTERNOON THUNDERSTORMS WILL INCREASE FIRE WEATHER CONCERNS. FRIDAY THROUGH MONDAY...HOT AFTERNOON TEMPERATURES IN THE 90S TO NEAR 100 CAN BE EXPECTED THROUGH THE REST OF THE WEEK AND INTO THE WEEKEND. A SLIGHT CHANCE OF THUNDERSTORMS WILL ALSO BE PRESENT EACH DAY AS THE ATMOSPHERE REMAINS UNSTABLE. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.
The Missoula radar (KMSX), 40 km away, was scanning. The volume nearest the first event began at 14:22 UTC.
2 thunderstorm wind. Local standard time, as filed.
Spotter report from Dixon School of fences, power poles and large spruce trees with 2 1/2 diameter trunks broken and blown over.
Severe thunderstorm winds blew down a large tree and several large branches in Ravalli.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2007Every state in 2007This day in weather historyWarnings in Montana, July 2007
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: 42334, 39361.