A thunderstorm developed near Macdonald Pass and became severe by dropping large hail.
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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 thunderstorm developed near Macdonald Pass and became severe by dropping large hail.
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 8, 4:40 PM MST, 5 minutes earlier.
Area Forecast Discussion National Weather Service Great Falls MT 540 PM MDT MON AUG 8 2016 Aviation section updated .DISCUSSION... Tonight through Wednesday...An unstable southwesterly flow aloft will reside over the region tonight. Expect scattered thunderstorms to develop mainly north of Dillon to Big Sky line this afternoon and gradually move northeastward through the evening. An isolated strong/severe storm will be possible. On Tuesday, an upper level low will move into western MT by late in the day. Expect another round of storms to move from south to north through the region. There is a better chance for severe storms on Tue with the dynamics/instability a bit stronger. On Wednesday, the upper level low pulls slowly north into Canada. There will be a small chance for a thunderstorm, mainly near the Canadian border. It will be a bit breezy/windy on Wednesday, especially over North Central MT in the wake of the departing upper level low. Temperatures will cool a few degrees each day for Tue and Wed, with highs around 80 on Tue cooling to the upper 60s and mid 70s for Wed. Brusda WEDNESDAY NIGHT THROUGH MONDAY...Forecast models are generally consistent with the overall pattern solution and timing of features during this period. The scattered showers and thunderstorms will decrease Wednesday night as the low pressure center of an upper level trough moves northeast of the forecast area. The trough itself will be slower to exit the area, leaving the area under a somewhat moist and unsettled northwesterly flow aloft Thursday through Friday. Instability will be weak during this time, but forecast models are hinting at a minimum of isolated shower/thunderstorm activity, so have increased pops generally to a slight chance across North Central Montana where upslope influence will be the greatest. A ridge of high pressure will then move into the area for Saturday into Sunday, which will keep the area dry. Similar to last night's model runs, Another upper level trough is forecast to move into the Pacific Northwest Sunday into Monday, putting the area under a more unstable southwesterly flow aloft. However, the forecast models disagree on shower/storm potential. The ECMWF keeps the area generally dry, and the GFS moves some isolated showers/storms over North Central Montana. With neither model showing anything significant, have increased pops a bit, but will monitor future model runs for consistency before increasing them further. With high pressure aloft moving into the area throughout the period, temperatures will gradually warm from about 5 degrees below normal on Thursday to around 5 degrees above normal by Sunday. However, with the potential for clouds/storms into Monday, temperatures will likely cool a few degrees over Sunday. Coulston && .AVIATION... UPDATED 2340z. Scattered thunderstorms will move northeast through the region this evening. Main threat will be lightning...wind gusts near 30kts and small hail. Expect a repeat of these conditions to develop after 20z on Tue, the but storms could be stronger, with a severe storm possible. VFR conditions will prevail outside of the thunderstorms. Brusda && .PRELIMINARY POINT TEMPS/POPS... GTF 52 82 48 75 / 30 50 70 20 CTB 46 76 48 69 / 20 70 70 30 HLN 50 81 51 77 / 20 60 40 10 BZN 43 85 47 79 / 20 20 20 10 WEY 35 73 36 69 / 10 10 10 0 DLN 45 79 42 76 / 20 10 20 10 HVR 56 84 54 75 / 30 60 70 30 LWT 52 83 51 76 / 30 40 40 10 && .TFX WATCHES/WARNINGS/ADVISORIES... FIRE WEATHER WATCH FOR PORTIONS OF SOUTHWEST MT FOR TUESDAY AFTERNOON AND EVENING. && weather.gov/greatfalls
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
1158 AM MDT MON AUG 08 2016
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0325 PM HAIL CLANCY 46.47N 111.99W
08/07/2016 E1.00 INCH JEFFERSON MT BROADCAST MEDIA
ESTIMATED QUARTER SIZE HAIL IN THE CLANCY AREA.
&&
BRUSDAPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
1212 PM MDT MON AUG 08 2016
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0445 PM HAIL 8 S BOULDER 46.12N 112.11W
08/07/2016 E1.00 INCH JEFFERSON MT PUBLIC
ESTIMATED QUARTER SIZE HAIL FALLING.
&&
BRUSDAPRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE GREAT FALLS MT
1216 PM MDT MON AUG 08 2016
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0100 PM HAIL WISDOM 45.62N 113.45W
08/07/2016 E0.25 INCH BEAVERHEAD MT FOREST SERVICE
PEA SIZE HAIL IN THE WISDOM AREA. TIME OF EVENT IS
ESTIMATED.
0315 PM HAIL 2 N CLANCY 46.49N 111.99W
08/07/2016 E0.25 INCH JEFFERSON MT PUBLIC
PEA SIZE HAIL. 0.61 INCHES OF RAIN IN 15 MINUTES.
0325 PM HAIL CLANCY 46.47N 111.99W
08/07/2016 E1.00 INCH JEFFERSON MT BROADCAST MEDIA
ESTIMATED QUARTER SIZE HAIL IN THE CLANCY AREA.
0340 PM HAIL 4 NNW WINSTON 46.52N 111.70W
08/07/2016 E1.50 INCH BROADWATER MT TRAINED SPOTTER
PING PONG SIZE HAIL FALLING.
0432 PM TSTM WND GST 8 SE BUTTE 45.92N 112.40W
08/07/2016 M58 MPH JEFFERSON MT DEPT OF HIGHWAYS
58 MPH WIND GUST AT HOMESTAKE PASS ON INTERSTATE 90.
0445 PM HAIL 8 S BOULDER 46.12N 112.11W
08/07/2016 E1.00 INCH JEFFERSON MT PUBLIC
ESTIMATED QUARTER SIZE HAIL FALLING.
0515 PM TSTM WND GST 8 W TOWNSEND 46.31N 111.70W
08/07/2016 M62 MPH BROADWATER MT MESONET
62 MPH WIND GUST AT THE ELKHORN RAWS LOCATION. TIME OF
EVENT IS ESTIMATED.
0535 PM HAIL 1 NW TOWNSEND 46.33N 111.54W
08/07/2016 E0.70 INCH BROADWATER MT TRAINED SPOTTER
DIME SIZE HAIL FALLING IN THE TOWNSEND AREA.
0547 PM HAIL TOWNSEND 46.32N 111.52W
08/07/2016 M1.25 INCH BROADWATER MT PUBLIC
STILL HAILING AT TIME OF CALL.
0550 PM TSTM WND GST 3 WNW TOWNSEND 46.33N 111.59W
08/07/2016 M66 MPH BROADWATER MT MESONET
66 MPH WIND GUST AT THE GINGER RAWS. TIME OF EVENT IS
ESTIMATED.
0552 PM TSTM WND GST 6 E GEYSER 47.28N 110.35W
08/07/2016 M56 MPH JUDITH BASIN MT OTHER FEDERAL
0555 PM TSTM WND GST 11 E TOWNSEND 46.33N 111.28W
08/07/2016 M52 MPH BROADWATER MT TRAINED SPOTTER
SPOTTER REPORTS DIME TO QUARTER SIZED HAIL
0555 PM HAIL 11 E TOWNSEND 46.33N 111.28W
08/07/2016 M1.00 INCH BROADWATER MT TRAINED SPOTTER
SPOTTER REPORTS DIME TO QUARTER SIZED HAIL
0555 PM HAIL 16 ENE SUNBURST 48.99N 111.60W
08/07/2016 E1.25 INCH TOOLE MT PUBLIC
NICKEL TO HALF DOLLAR SIZE HAIL FALLING.
0600 PM HAIL 5 SW WINDHAM 47.04N 110.22W
08/07/2016 M1.00 INCH JUDITH BASIN MT TRAINED SPOTTER
HAIL RANGED FROM PEA SIZED TO LARGER THAN A QUARTER
0725 PM HAIL 1 NW SUNBURST 48.88N 111.91W
08/07/2016 E1.75 INCH TOOLE MT TRAINED SPOTTER
GOLF BALL SIZE HAIL FALLING NEAR SUNBURST.
0730 PM HAIL 4 WNW SUNBURST 48.90N 111.99W
08/07/2016 E1.00 INCH TOOLE MT TRAINED SPOTTER
HAIL UP TO QUARTER SIZE FALLING. HAIL A FEW INCHES DEEP
IN PLACES. WIND GUSTS ESTIMATED AROUND 50 MPH.
0745 PM HAIL 4 WNW SUNBURST 48.90N 111.99W
08/07/2016 M1.00 INCH TOOLE MT TRAINED SPOTTER
QUARTER SIZED HAIL REPORTED JUST WEST OF SUNBURST. TIME
ESTIMATED BASED ON RADAR.
0850 PM HAIL 8 NW WHITLASH 48.98N 111.40W
08/07/2016 M1.00 INCH TOOLE MT TRAINED SPOTTER
STORM SPOTTER REPORTS QUARTER SIZED HAIL
0850 PM TSTM WND GST 8 NW WHITLASH 48.98N 111.40W
08/07/2016 E50 MPH TOOLE MT TRAINED SPOTTER
STORM SPOTTER REPORTS QUARTER SIZED HAIL
&&
BRUSDAThe Great Falls radar (KTFX), 121 km away, was scanning. The volume nearest the first event began at 23:46 UTC.
1 hail. Local standard time, as filed.
A thunderstorm dropped 1.25 inch diameter hail at Marysville 13S (the Macdonald Pass DOT site).
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2016Every state in 2016This day in weather historyWarnings in Montana, August 2016
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: 644431.