A shortwave passing across the region, combined with monsoonal flow and inverted V soundings, resulted in many severe wind gusts in the late afternoon/evening. A single severe hail report was received near Shelby.
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 shortwave passing across the region, combined with monsoonal flow and inverted V soundings, resulted in many severe wind gusts in the late afternoon/evening. A single severe hail report was received near Shelby.
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 12, 1:47 PM MST, 2 hours 48 minutes earlier.
Area Forecast Discussion National Weather Service Great Falls MT 247 PM MDT Fri Aug 12 2022 .SYNOPSIS... Scattered showers and thunderstorms are likely across Southwest and Central Montana through late evening. Some thunderstorms could produce locally damaging wind gusts. Overall hot and dry conditions continue, keeping most locations in the upper 80s and 90s through next week. && .DISCUSSION... Thunderstorms continue to develop over Central Idaho this afternoon associated with a strong southwesterly jet streak. Modest convective instability will allow for continued development. As developing storms move across the Continental Divide into Central Montana, they are expected to be maintained as elevated linear segments. Downdraft CAPE values also exceed 1000 J/Kg with deep inverted-V profiles. Precipitable water is above the 90th percentile for this time of year. Hence, convective cores will be capable of producing heavy precipitation aloft, but evaporative cooling with the descending storm cores will result in primarily a convective wind gust hazard through late this evening. In addition to the wind hazard, efficient lightning will maintain a high potential for new fire starts on dry and highly receptive fuels. Thunderstorm activity clears away to the east through the early morning hours Saturday. Isolated to scattered thunderstorms are expected once again on Saturday afternoon, but with less coverage and likely further south. A weak frontal boundary passes Saturday night, with drier air following into Sunday. The persistent and dominant upper level ridge rebuilds into next week. Ensemble cluster analyses indicate few differences among the range of forecast guidance, suggesting high confidence that the ridge will persist with continued above normal temperatures. The change will be toward drier conditions, with lower precipitable water and afternoon relative humidity dropping to near 10 percent for some drier locations into next week. Fortunately in this pattern the overall winds remain light, but it doesn't take much for thunderstorms developing further west to drift into the upstream side of the ridge and produce a lightning hazard. The robust ridge shows signs of breaking down by next weekend, with around 20 percent of the ensemble members indicating a ridge collapse and transition to a cooler northwesterly flow. && .AVIATION... 1150 AM MDT Fri Aug 11 2022 (12/18Z TAF period) VFR conditions will prevail through early afternoon; however, showers and thunderstorms are then expected through the evening for most terminals. These showers, moving southwest to northeast, are expected to produce erratic gusty winds in excess of 40 knots, and lightning. Shower activity continues during the overnight hours for eastern portions of Central and North-central Montana before exiting the region early Saturday morning. && .PRELIMINARY POINT TEMPS/POPS... GTF 60 96 57 92 / 60 10 10 10 CTB 58 92 52 86 / 50 10 0 0 HLN 62 95 60 93 / 60 20 10 10 BZN 56 92 56 90 / 40 30 20 20 WYS 47 80 46 80 / 40 60 30 40 DLN 54 87 52 86 / 50 30 10 20 HVR 62 96 60 91 / 60 20 10 0 LWT 59 91 57 88 / 70 20 10 20 && .TFX WATCHES/WARNINGS/ADVISORIES... None. && http://www.weather.gov/greatfalls
Special Weather Statement
National Weather Service Great Falls MT
446 PM MDT Fri Aug 12 2022
MTZ008-122330-
Beaverhead MT-
446 PM MDT Fri Aug 12 2022
...A strong thunderstorm will impact portions of central Beaverhead
County through 530 PM MDT...
At 446 PM MDT, Doppler radar was tracking a strong thunderstorm 18
miles northwest of Dillon, moving east at 20 mph.
HAZARD...Winds in excess of 40 mph and half inch hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible.
This storm will remain over mainly rural areas of central Beaverhead
County.
This includes Interstate 15 between mile markers 73 and 75 .
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
A Severe Thunderstorm Watch remains in effect until 900 PM MDT for
southwestern Montana.
&&
LAT...LON 4526 11306 4540 11310 4552 11275 4523 11266
TIME...MOT...LOC 2246Z 258DEG 17KT 4533 11297
MAX HAIL SIZE...0.50 IN
MAX WIND GUST...40 MPH
RCGSpecial Weather Statement
National Weather Service Great Falls MT
451 PM MDT Fri Aug 12 2022
MTZ047-122330-
Blaine MT-
451 PM MDT Fri Aug 12 2022
...Strong thunderstorm wind gusts will impact portions of
northeastern Blaine County through 530 PM MDT...
At 449 PM MDT, Doppler radar was tracking strong thunderstorm wind
gusts along the Canadian border. Movement was southeast at 30 mph.
HAZARD...Winds in excess of 40 mph.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects.
Locations impacted include...
Turner and Hogeland.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
&&
LAT...LON 4892 10824 4891 10826 4881 10825 4871 10905
4899 10945 4900 10931 4900 10824
TIME...MOT...LOC 2249Z 301DEG 23KT 4922 10839 4903 10873 4892 10935
MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH
RCGSpecial Weather Statement
National Weather Service Great Falls MT
514 PM MDT Fri Aug 12 2022
MTZ010-044-130000-
Eastern Glacier MT-Toole MT-
514 PM MDT Fri Aug 12 2022
...Strong thunderstorms will impact portions of northeastern Glacier
and northwestern Toole Counties through 600 PM MDT...
At 513 PM MDT, Doppler radar was tracking strong thunderstorms along
a line extending from 28 miles northwest of Kevin to 13 miles west of
Sunburst to 13 miles north of Cut Bank. Movement was east at 25 mph.
HAZARD...Winds in excess of 40 mph and half inch hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible.
Locations impacted include...
Sunburst, Kevin, Oilmont and Santa Rita.
This includes Interstate 15 between mile markers 376 and 397.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
These storms may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.
&&
LAT...LON 4899 11172 4891 11173 4868 11185 4879 11246
4896 11235 4900 11234
TIME...MOT...LOC 2313Z 272DEG 21KT 4913 11221 4894 11219 4883 11230
MAX HAIL SIZE...0.50 IN
MAX WIND GUST...40 MPH
RCGSpecial Weather Statement
National Weather Service Great Falls MT
519 PM MDT Fri Aug 12 2022
MTZ009-010-046-130000-
Northern Rocky Mountain Front MT-Eastern Glacier MT-
Eastern Pondera MT-
519 PM MDT Fri Aug 12 2022
...Strong thunderstorms will impact portions of north central Pondera
and southeastern Glacier Counties through 600 PM MDT...
At 519 PM MDT, Doppler radar was tracking strong thunderstorms along
a line extending from near South Browning to 6 miles east of Heart
Butte. Movement was northeast at 15 mph.
HAZARD...Winds in excess of 40 mph and half inch hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible.
Locations impacted include...
Browning, South Browning, North Browning and Heart Butte.
This includes the following highways...
Highway 2 between mile markers 221 and 243.
Highway 89 between mile markers 83 and 110.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
&&
LAT...LON 4882 11280 4839 11230 4821 11272 4849 11308
TIME...MOT...LOC 2319Z 208DEG 12KT 4850 11296 4831 11271
MAX HAIL SIZE...0.50 IN
MAX WIND GUST...40 MPH
RCGSpecial Weather Statement
National Weather Service Great Falls MT
527 PM MDT Fri Aug 12 2022
MTZ008-015-130000-
Madison MT-Beaverhead MT-
527 PM MDT Fri Aug 12 2022
...A strong thunderstorm will impact portions of west central Madison
and central Beaverhead Counties through 600 PM MDT...
At 527 PM MDT, Doppler radar was tracking a strong thunderstorm 12
miles north of Dillon, moving east at 30 mph.
HAZARD...Wind gusts up to 50 mph and penny size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible.
Locations impacted include...
Glen.
This includes Interstate 15 between mile markers 70 and 82 .
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.
A Severe Thunderstorm Watch remains in effect until 900 PM MDT for
southwestern Montana.
&&
LAT...LON 4532 11282 4548 11281 4554 11225 4522 11225
TIME...MOT...LOC 2327Z 277DEG 26KT 4540 11268
MAX HAIL SIZE...0.75 IN
MAX WIND GUST...50 MPH
RCGSpecial Weather Statement
National Weather Service Great Falls MT
535 PM MDT Fri Aug 12 2022
MTZ009-046-048-049-130015-
Southern Rocky Mountain Front MT-Northern Rocky Mountain Front MT-
Eastern Teton MT-Eastern Pondera MT-
535 PM MDT Fri Aug 12 2022
...A strong thunderstorm will impact portions of central Pondera and
north central Teton Counties through 615 PM MDT...
At 534 PM MDT, Doppler radar was tracking a strong thunderstorm 14
miles south of Valier, or 17 miles west of Conrad, moving east at 20
mph.
HAZARD...Wind gusts up to 50 mph and penny size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible.
Locations impacted include...
Conrad and Pendroy.
This includes Highway 89 between mile markers 56 and 71.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.
&&
LAT...LON 4798 11237 4814 11248 4835 11210 4806 11188
TIME...MOT...LOC 2334Z 250DEG 18KT 4810 11231
MAX HAIL SIZE...0.75 IN
MAX WIND GUST...50 MPH
RCGThe national radar mosaic for the moment the first event began.
9 thunderstorm wind, 1 hail. Local standard time, as filed.
Pictures were received from a farmer in Toole county showing numerous nickel to quarter sized hail stones.
Mesonet station Sieben Flats MDT.
A 59 mph gust was recorded by an Ambient weather sensor.
Social media report (image) received showing a 6 to 8 inch limb that was knocked down west of Vaughn. Size of limb is estimated.
Mesonet MTM76 Cascade e mda.
Trained spotter reports an estimated wind gust of at least 70 mph. Time estimated by spotter.
Mesonet fw1664 Hingham.
An Ambient weather station measured a 70 mph gust in northern Hill county.
Ambient weather sensor.
Mesonet station kmthavre60.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2022Every state in 2022This day in weather historyWarnings in Montana, August 2022
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: 1051394, 1051399, 1051400, 1051396, 1051401, 1051402, 1051403, 1051404, 1051405, 1051406.