A very unstable and moist airmass allowed severe thunderstorms to develop during the late afternoon and early evening hours. Hail the size of half dollars and wind gusts in excess of 60 mph were reported.
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 TFX wrote it up.
A very unstable and moist airmass allowed severe thunderstorms to develop during the late afternoon and early evening hours. Hail the size of half dollars and wind gusts in excess of 60 mph were reported.
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 Great Falls, MT wrote its last area forecast discussion before the first event at Aug 9, 8:50 AM MST, 3 hours 25 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREAT FALLS MT 950 AM MDT SAT AUG 9 2008 .UPDATE...SLIGHT TWEAKS TO POP/QPF/WEATHER GRIDS FOR TODAY MAINLY TO INCREASE POPS IN SW MT THIS MORNING AND OVER ALL BUT THE FAR NE CORNER OF THE CWA FOR THIS AFTN. SHORTWAVE TROF IS LIFTING NEWD ACROSS ERN ID/WRN MT THIS MORNING WITH RADAR SHOWING AREAS OF MODERATE THUNDERSTORMS IN THOSE AREAS. AIRMASS OVER THE CWA IS ALREADY MARGINALLY UNSTABLE AS SEEN IN 12Z SOUNDING AND SPOTTY CONVECTIVE CLOUD DEVELOPMENT. THUNDERSTORMS STILL A GOOD BET OVER MOST AREAS THIS AFTN/EVE...BUT SEVERE PARAMETERS ARE MARGINAL RIGHT NOW...BUT STRONG HEATING MAY CREATE MORE FAVORABLE SEVERE CONDITIONS LATER. WARANAUSKAS .DISCUSSION... TODAY THROUGH MONDAY...UPPER RIDGE HOLDING IN PLACE OVER THE COUNTY WARNING AREA TODAY BUT BEGINNING TO ERODE ON THE WESTERN FLANK AS AN UPPER LOW APPROACHES THE PACIFIC NORTHWEST. SHORT WAVE ENERGY WILL CONTINUE TO SPIN OUT FROM THE LOW AND MOVE WITHIN THE SOUTHWEST FLOW ALOFT. THUNDERSTORMS WILL AGAIN DEVELOP IN THE UNSTABLE AIRMASS AND BECOME MORE WIDESPREAD THAN FRIDAYS ACTIVITY. SPC MAINTAINS A SLIGHT RISK OUTLINE OVER WESTERN MONTANA TODAY AND SOME STORMS COULD BECOME SEVERE. A SURFACE COLD FRONT WILL MOVE ACROSS THE AREA LATE TONIGHT WITH THUNDERSTORM ACTIVITY CONTINUING TO PRECEDE THIS EVENT. THE UPPER LOW TRACKS ACROSS SOUTHERN CANADA ON SUNDAY WITH LINGERING CONVECTIVE ACTIVITY OVER THE EASTERN PORTION OF THE COUNTY WARNING AREA. THE UPPER LOW SLIDES ACROSS SASKATCHEWAN ON MONDAY THEREBY ENDING CONVECTIVE ACTIVITY ACROSS THE AREA. COOLER AIR WILL MAKES ITS WAY OVER THE AREA MONDAY. TEMPERATURES WILL REMAIN ABOVE SEASONAL AVERAGES. EMANUEL MONDAY NIGHT THROUGH THURSDAY NIGHT...UPPER LEVEL LOW MOVES EAST/SOUTHEAST OUT OF ALBERTA INTO SASKATCHEWAN WITH SOUTHERN PORTION OF LOW PRESSURE TROUGH EXITING CWA MONDAY NIGHT. GFS AND ECMWF MODELS STILL SHOWING SLIGHTLY DIFFERENT SOLUTIONS...GFS HAS LOW CENTERED SLIGHTLY FURTHER SOUTH WITH MORE ENERGY DRAGGING ACROSS NORTHERN PORTION OF CWA WHILE ECMWF HAS LOW AND ASSOCIATED ENERGY FURTHER NORTH AND MOSTLY OUT OF CWA. EITHER WAY...CHANCES OF PRECIPITATION ARE SMALL AT THAT POINT. TUESDAY...BIGGER DIFFERENCES IN THE MODELS BECOME EVIDENT. GFS DROPS THE LOW TO THE SOUTH/SOUTHEAST INTO THE NORTHEAST CORNER OF MONTANA WHILE THE ECMWF MOVES IT FURTHER ACROSS SASKATCHEWAN AND HAS A WEAK RIDGE REBUILDING OVER THE CWA WEDNESDAY AND THURSDAY. HAVE LEANED TOWARD THE ECMWF GOING WITH LOW CHANCES OF PRECIPITATION AND WARMING TEMPERATURES MID-WEEK. EXPECT TEMPERATURES TUESDAY TO BE A FEW DEGREES BELOW SEASONAL NORMALS THEN REBOUNDING TO NEAR SEASONAL NORMALS WEDNESDAY AND THURSDAY. LITTLE CHANCE OF PRECIPITATION THROUGH THE PERIOD. FRIDAY THROUGH SATURDAY...MODEL DIFFERENCES DETRACT A LITTLE FROM FORECAST CONFIDENCE DURING THIS PERIOD. I WENT WITH A COMPROMISE OF AN UPPER LEVEL RIDGE OF HIGH PRESSURE LINGERING OVER MONTANA DURING THIS PERIOD. WARM AND DRY CONDITIONS ARE EXPECTED. HOWEVER...A FEW WEAK DISTURBANCES WITH LIMITED MOISTURE WORK THEIR WAY THROUGH THE RIDGE. A FEW MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS ARE POSSIBLE. TEMPERATURES ARE EXPECTED TO BE JUST A FEW DEGREES ABOVE SEASONAL AVERAGES. EK && .AVIATION... UPDATED 1135Z. VFR CONDITIONS EARLY IN PERIOD. UNSTABLE SOUTHWESTERLY FLOW ALOFT AND APPROACHING COLD FRONT WILL RESULT IN DEVELOPMENT OF WIDESPREAD THUNDERSTORMS...SOME POSSIBLY STRONG/SEVERE... AFTER 20Z. STRONG GUSTY WINDS...BRIEF HEAVY RAINFALL...AND HAIL ARE EXPECTED WITH THE THUNDERSTORMS WITH OCCASIONAL MVFR CONDITIONS. MOST THUNDERSTORMS WILL MOVE INTO EASTERN MONTANA AFTER 03Z WITH VFR CONDITIONS THEN PREVAILING. && .PRELIMINARY POINT TEMPS/POPS... GTF 93 56 83 47 / 30 40 20 30 CTB 88 51 76 44 / 20 40 10 20 HLN 91 58 84 52 / 30 40 10 20 BZN 92 52 89 47 / 30 40 30 30 WEY 78 45 76 40 / 50 60 20 20 DLN 82 49 82 44 / 40 40 10 20 HVR 94 56 87 48 / 20 40 20 40 LWT 89 55 81 47 / 30 40 30 40 && .TFX WATCHES/WARNINGS/ADVISORIES... NONE. && SHORT TERM...EMANUEL LONG TERM...LOSS/EK AVIATION...LOSS WEATHER.GOV/GREATFALLS
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GREAT FALLS MT 515 AM MDT SAT AUG 9 2008 MTZ008>015-044>055-101115- BEAVERHEAD-NORTHERN ROCKY MOUNTAIN FRONT-EASTERN GLACIER-HILL- CASCADE-CHOUTEAU-CENTRAL AND SOUTHERN LEWIS AND CLARK-MADISON- TOOLE-LIBERTY-EASTERN PONDERA-BLAINE- SOUTHERN ROCKY MOUNTAIN FRONT-EASTERN TETON-JUDITH BASIN-FERGUS- JEFFERSON-BROADWATER-MEAGHER-GALLATIN- 515 AM MDT SAT AUG 9 2008 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL MONTANA...NORTH CENTRAL MONTANA AND SOUTHWEST MONTANA. .DAY ONE...TODAY AND TONIGHT SCATTERED THUNDERSTORMS ARE POSSIBLE TODAY AND TONIGHT. SOME THUNDERSTORMS MAY BECOME STRONG WITH GUSTY WINDS...HEAVY RAIN AND HAIL. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY NO HAZARDOUS WEATHER IS EXPECTED. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.
The Pocatello radar (KSFX), 167 km away, was scanning. The volume nearest the first event began at 19:17 UTC.
11 thunderstorm wind, 3 hail. Local standard time, as filed.
A severe thunderstorm dropped 1.25 inch diameter hail at Lima 6ESE. The hail contributed to a vehicle accident on Interstate 15.
A severe thunderstorm produced a wind gust to 65 mph at Augusta 4W.
A severe thunderstorm produced a wind gust to 60 mph at Wolf Creek 3NNE.
A severe thunderstorm produced a wind gust to 65 mph at Choteau Airport 1NE.
A severe thunderstorm produced a wind gust to 60 mph at Vaughn.
A severe thunderstorm produced a wind gust to 70 mph at Conrad 3SW.
A severe thunderstorm dropped 1 inch diameter hail at Lima 3SE.
A severe thunderstorm produced a wind gust to 70 mph at Valier.
A severe thunderstorm produced a wind gust to 64 mph at Highwood 7SW.
A severe thunderstorm produced a wind gust to 60 mph at Shelby 2SE.
A severe thunderstorm produced a wind gust to 70 mph at Cameron 12S.
A severe thunderstorm produced a wind gust to 60 mph at Simpson 5WNW.
A severe thunderstorm produced a wind gust to 60 mph at Chinook 7NE.
A severe thunderstorm dropped 1 inch diameter hail at Big Sky 2E.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2008Every state in 2008This day in weather historyWarnings in Montana, August 2008
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: 127445, 127446, 127449, 127447, 127451, 127457, 127452, 127455, 127464, 127456, 127459, 127460, 127461, 127462.