Thunderstorms developed over Blaine County over a few days producing gusty outflow winds.
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.
Thunderstorms developed over Blaine County over a few days producing gusty outflow winds.
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 Jul 28, 1:55 PM MST, 3 hours 5 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREAT FALLS MT 255 PM MDT SAT JUL 28 2012 .DISCUSSION... THIS AFTERNOON THROUGH MONDAY EVENING...HOT AND MOSTLY DRY CONDITIONS CONTINUE ACROSS OUR REGION THIS AFTN AS BROAD HIGH PRESSURE RIDGE REMAINS PARKED OVER THE NRN/CENTRAL ROCKIES. TWO AREAS OF MOISTURE...A PACIFIC PLUME ALONG THE HILINE AND US/CAN BORDER AND A MONSOONAL PLUME OVER SOUTHWEST MT...ARE COMBINING WITH GOOD INSTABILITY TO SPARK SCATTERED THUNDERSTORMS IN THOSE AREAS. A FEW OF THE HILINE STORMS HAVE ALREADY REACHED STRONG TO SEVERE CRITERIA WITH LARGE HAIL REPORTED SHORTLY AFTER 2PM. CURRENT FORECAST CALLS FOR ADDITIONAL SCATTERED THUNDERSTORMS ACROSS MUCH OF THE FORECAST AREA THIS AFTN/EVE...WITH A CHANCE FOR LATER STORMS TO ALSO BECOME STRONG-TO-SEVERE. SIMILAR TO PAST SEVERAL DAYS...EXPECT THE STORM ACTIVITY TO DISSIPATE AND/OR MOVE INTO ERN MT BY MID-TO-LATE EVENING WITH CLEARING SKIES OVERNIGHT. FORECAST MODELS SHOWING LITTLE CHANGE IN CONDITIONS FOR SUNDAY WITH CONTINUED HOT TEMPERATURES AND SCATTERED AFTN/EVE STORMS. MODELS HAVE BEEN CONSISTENT IN SHOWING MAIN AREA OF STORMS BEING FROM BUTTE/HELENA TO LEWISTOWN...WITH MARKEDLY LESS STORM COVERAGE FROM GREAT FALLS NORTHWARD TO THE HILINE AS DRIER AIR MOVES THROUGH THE NRN FLANK OF THE RIDGE. MONDAY LOOKS QUITE A BIT DRIER ACROSS OUR REGION AS THE RIDGE AXIS IS PROJECTED TO BE RIGHT THROUGH CENTRAL MT AND THE MONSOONAL MOISTURE PLUME IS DEFLECTED WELL SOUTHEAST INTO WYOMING. HIGH TEMPERATURES WILL AGAIN REACH THE LOW 90S TOMORROW AND CLIMB INTO THE MID 90S OVER THE PLAINS/VALLEYS ON MON. WARANAUSKAS MONDAY NIGHT THROUGH SATURDAY...AN UPPER RIDGE MAINTAINS ITS PRESENCE OVER THE AREA TO START THE MEDIUM RANGE PERIOD BUT GETS FLATTENED BY WEDNESDAY AS A SERIES OF UPPER DISTURBANCES MOVES ACROSS SOUTHERN CANADA. DRY AND WARM CONDITIONS WILL RESULT TUESDAY AND WEDNESDAY. THE FLOW ALOFT BEGINS TO TURN CYCLONIC ON THURSDAY AS AN UPPER TROF MOVES TO THE PACIFIC NORTHWEST. ISOLATED THUNDERSTORMS WILL BE MOSTLY CONFINED TO ALONG THE CONTINENTAL DIVIDE. FRIDAY WILL SEE THE UPPER TROF BEGIN TO DROP SOUTH OUT OF CANADA AND DRAG A SURFACE COLD FRONT ACROSS THE AREA. TEMPERATURES WILL COOL DOWN FROM THE PERSISTENT 90 DEGREES OF THE PAST WEEK. ISOLATED TO SCATTERED THUNDERSTORMS WILL ALSO ACCOMPANY THE COLD FRONTAL PASSAGE. MODELS DIFFER ON THEIR SOLUTION FOR SATURDAY WITH THE EUROPEAN MODEL MOVING THE UPPER TROF QUICKLY OUT OF THE AREA WHILE THE GFS KEEPS IT IN PLACE OVER MONTANA. WILL LEAN TOWARD THE MORE PROGRESSIVE EUROPEAN SOLUTION WHICH REBUILDS THE UPPER RIDGE IN THE WAKE OF THE TROF PASSAGE. THIS WOULD SEEM A LOGICAL SOLUTION GIVEN THE TIME OF YEAR. AT ANY RATE...TEMPERATURES OVER THE WEEKEND WILL OFFER A BRIEF RESPITE FROM THE RECENT HEAT. AFTERNOON READINGS WILL REMAIN ABOVE SEASONAL AVERAGES TO START THE WEEK BUT WILL DROP TO BELOW SEASONAL AVERAGES BY SATURDAY. && .AVIATION... UPDATED 1720Z. MOSTLY SUNNY SKIES WILL GIVE WAY TO SCATTERED CLOUDS AND ISOLATED TO SCATTERED THUNDERSTORMS THIS AFTERNOON AS WEAK DISTURBANCES CONTINUE TO MOVE TROUGH THE AREA. ONE AREA OF STORMS WILL DEVELOP ALONG THE ROCKY MOUNTAIN FRONT AND PUSH EAST INTO THE PLAINS AFTER 20Z... POSSIBLY AFFECTING KCTB AND KGTF. OTHER THUNDERSTORMS WILL FORM OVER SOUTHWEST MONTANA LATE IN THE AFTERNOON AND CONTINUE INTO THE EVENING. A FEW OF THE THUNDERSTORMS COULD BECOME SEVERE IN SOUTHWEST AND CENTRAL MONTANA. MVFR AND IFR CONDITIONS WILL BE POSSIBLE WITH ANY OF THE STRONGER STORMS...MAINLY DUE TO VISIBILITY IN HEAVY RAIN. THUNDERSTORMS WILL DIMINISH EARLY IN THE EVENING FOR MOST LOCATIONS...BUT WILL LINGER OVER THE MOUNTAIN AREAS OF CENTRAL && .PRELIMINARY POINT TEMPS/POPS... GTF 56 91 58 95 / 20 10 10 20 CTB 51 86 53 89 / 10 10 10 20 HLN 58 91 59 93 / 30 10 20 10 BZN 51 91 52 93 / 30 20 20 10 WEY 43 83 42 83 / 20 10 10 10 DLN 52 89 53 90 / 20 20 10 10 HVR 55 91 57 95 / 20 0 10 20 LWT 54 87 55 91 / 40 20 20 20 && .TFX WATCHES/WARNINGS/ADVISORIES... NONE. && SHORT TERM...WARANAUSKAS LONG TERM...EMANUEL AVIATION...LANGLIEB WEATHER.GOV/GREATFALLS
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GREAT FALLS MT 408 AM MDT SAT JUL 28 2012 MTZ008>015-044>055-291200- 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- 408 AM MDT SAT JUL 28 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL MONTANA...NORTH CENTRAL MONTANA AND SOUTHWEST MONTANA. .DAY ONE...TODAY AND TONIGHT THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE GREAT FALLS MT 227 PM MDT SAT JUL 28 2012 MTZ009-044-046-048-049-282130- EASTERN PONDERA MT-EASTERN TETON MT-NORTHERN ROCKY MOUNTAIN FRONT MT-SOUTHERN ROCKY MOUNTAIN FRONT MT-TOOLE MT- 227 PM MDT SAT JUL 28 2012 ...SIGNIFICANT WEATHER ADVISORY FOR EASTERN PONDERA...NORTHERN TETON AND SOUTHERN TOOLE COUNTIES UNTIL 330 PM MDT... AT 224 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 9 MILES WEST OF CONRAD...MOVING EAST AT 25 MPH. HAIL UP TO THREE QUARTERS OF AN INCH IN DIAMETER IS POSSIBLE WITH THIS STORM. LOCATIONS NEAR THE PATH OF THIS STORM INCLUDE...CONRAD AND LEDGER. THIS STORM MAY INTENSIFY...SO BE CERTAIN TO MONITOR LOCAL RADIO AND TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS...FOR ADDITIONAL INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE. LAT...LON 4842 11167 4812 11148 4798 11229 4816 11242 TIME...MOT...LOC 2027Z 250DEG 20KT 4814 11212 GUSTAFSON
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE GREAT FALLS MT 304 PM MDT SAT JUL 28 2012 MTZ011-013-044>046-282145- CHOUTEAU MT-EASTERN PONDERA MT-HILL MT-LIBERTY MT-TOOLE MT- 304 PM MDT SAT JUL 28 2012 ...SIGNIFICANT WEATHER ADVISORY FOR EXTREME EASTERN PONDERA... SOUTHEASTERN TOOLE...SOUTHERN LIBERTY...SOUTHWESTERN HILL AND EXTREME NORTHERN CHOUTEAU COUNTIES UNTIL 345 PM MDT... AT 301 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 13 MILES SOUTH OF LOTHAIR...OR 23 MILES SOUTHWEST OF CHESTER...MOVING EAST AT 30 MPH. HAIL UP TO THE SIZE OF NICKELS IS EXPECTED WITH THIS STORM. * LOCATIONS IMPACTED INCLUDE... RURAL SOUTHWESTERN LIBERTY COUNTY... RURAL SOUTHEASTERN TOOLE COUNTY... RURAL SOUTHERN LIBERTY COUNTY... RURAL CENTRAL LIBERTY COUNTY... RURAL SOUTHWESTERN HILL COUNTY... RURAL NORTHERN CHOUTEAU COUNTY... LAT...LON 4852 11068 4828 11060 4819 11142 4836 11148 TIME...MOT...LOC 2104Z 257DEG 27KT 4830 11131 SUK
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
309 PM MDT SAT JUL 28 2012
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0245 PM HAIL 10 S DEVON 48.32N 111.49W
07/28/2012 E0.50 INCH TOOLE MT TRAINED SPOTTER
&&
PNPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
330 PM MDT SAT JUL 28 2012
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0329 PM HAIL 13 SSE LOTHAIR 48.31N 111.09W
07/28/2012 E0.50 INCH LIBERTY MT TRAINED SPOTTER
&&
PNPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
416 PM MDT SAT JUL 28 2012
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0245 PM HEAVY RAIN 12 E LEDGER 48.29N 111.57W
07/28/2012 M1.03 INCH TOOLE MT TRAINED SPOTTER
1.03 INCHES THUNDERSTORM TOTAL RAINFALL. 0.76 INCHES OF
THIS TOTAL FELL IN LESS THAN 20 MINUTES.
&&
PNPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
547 PM MDT SAT JUL 28 2012
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0440 PM HAIL 1 SE HELENA 46.59N 112.00W
07/28/2012 M0.50 INCH LEWIS AND CLARK MT TRAINED SPOTTER
&&
PNThe Great Falls radar (KTFX), 193 km away, was scanning. The volume nearest the first event began at 00:03 UTC.
2 thunderstorm wind. Local standard time, as filed.
Thunderstorm outflow winds produced wind gusts to 62KT (71MPH) 11 miles S of Chinook.
Thunderstorm outflow winds produced wind gusts to 57KT (65MPH) 11 miles S of Chinook.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2012Every state in 2012This day in weather historyWarnings in Montana, July 2012
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: 406156, 406157.