A north/south line of thunderstorms that stretched across multiple counties produced outflow winds well ahead of the thunderstorms. This outflow was very strong and produced winds over 60 mph. These winds produced an area of blowing dust across Interstate 90 just west of Hardin. Visibility dropped to zero resulting in a multiple car pileup which resulted in several deaths and multiple injuries.

Thunderstorm Wind in BIG HORN, MONTANA
From 15-JUL-22 15:30:00 to 15-JUL-22 15:30:00 (MST-7)
Location: HARDIN
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Around 4:15 PM MDT, a thunderstorm outflow moved through the Hardin area. It produced a wind gust of 62 mph in the 4:35 PM MDT observations from the Big Horn County Airport. Along with the outflow winds, blowing dust reduced visibility to less than a quarter mile on the AWOS. This resulted in a 20 to 30 vehicle pile up along Interstate 90 around mile marker 493 reported at 4:30 PM MDT, very close to the airport. Prior to this, the Montana DOT RWIS station at Arrow Creek Hill, 25 miles west of Hardin, reported a peak wind gust of 48 mph about 15 minutes prior. This accident resulted in 6 deaths and multiple injuries.

Hail in STILLWATER, MONTANA
From 15-JUL-22 14:19:00 to 15-JUL-22 14:19:00 (MST-7)
Location: NYE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in YELLOWSTONE, MONTANA
From 15-JUL-22 14:20:00 to 15-JUL-22 14:20:00 (MST-7)
Location: LAUREL
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in YELLOWSTONE, MONTANA
From 15-JUL-22 14:20:00 to 15-JUL-22 14:20:00 (MST-7)
Location: LAUREL MUNI ARPT
Magnitude: 1.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorm Wind in YELLOWSTONE, MONTANA
From 15-JUL-22 14:40:00 to 15-JUL-22 14:40:00 (MST-7)
Location: BILLINGS
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A 1.5 foot diameter tree was downed.

Thunderstorm Wind in BIG HORN, MONTANA
From 15-JUL-22 15:50:00 to 15-JUL-22 15:50:00 (MST-7)
Location: HARDIN AIRPARK
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A mobile home lost its roof.

Thunderstorm Wind in WHEATLAND, MONTANA
From 15-JUL-22 12:02:00 to 15-JUL-22 12:02:00 (MST-7)
Location: TWODOT
Magnitude: 52.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorm Wind in YELLOWSTONE, MONTANA
From 15-JUL-22 14:15:00 to 15-JUL-22 14:15:00 (MST-7)
Location: ACTON
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in WHEATLAND, MONTANA
From 15-JUL-22 12:06:00 to 15-JUL-22 12:06:00 (MST-7)
Location: TWODOT
Magnitude: 52.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorm Wind in YELLOWSTONE, MONTANA
From 15-JUL-22 14:23:00 to 15-JUL-22 14:23:00 (MST-7)
Location: BILLINGS HGTS
Magnitude: 56.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in YELLOWSTONE, MONTANA
From 15-JUL-22 14:25:00 to 15-JUL-22 14:25:00 (MST-7)
Location: BILLINGS LOGAN ARPT
Magnitude: 53.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Thunderstorm Wind in BIG HORN, MONTANA
From 15-JUL-22 15:05:00 to 15-JUL-22 15:05:00 (MST-7)
Location: HARDIN
Magnitude: 66.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorm Wind in BIG HORN, MONTANA
From 15-JUL-22 15:30:00 to 15-JUL-22 15:30:00 (MST-7)
Location: HARDIN
Magnitude: 56.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Thunderstorm Wind in BIG HORN, MONTANA
From 15-JUL-22 15:55:00 to 15-JUL-22 15:55:00 (MST-7)
Location: HARDIN
Magnitude: 56.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Visibility was under a quarter mile due to blowing dust.

Thunderstorm Wind in ROSEBUD, MONTANA
From 15-JUL-22 15:30:00 to 15-JUL-22 15:30:00 (MST-7)
Location: ANGELA
Magnitude: 56.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Thunderstorm Wind in ROSEBUD, MONTANA
From 15-JUL-22 15:57:00 to 15-JUL-22 15:57:00 (MST-7)
Location: INGOMAR
Magnitude: 52.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Thunderstorm Wind in ROSEBUD, MONTANA
From 15-JUL-22 16:04:00 to 15-JUL-22 16:04:00 (MST-7)
Location: INGOMAR
Magnitude: 56.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Thunderstorm Wind in ROSEBUD, MONTANA
From 15-JUL-22 16:19:00 to 15-JUL-22 16:19:00 (MST-7)
Location: INGOMAR
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Thunderstorm Wind in CARBON, MONTANA
From 15-JUL-22 16:29:00 to 15-JUL-22 16:29:00 (MST-7)
Location: HILLSBORO
Magnitude: 58.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Thunderstorm Wind in ROSEBUD, MONTANA
From 15-JUL-22 17:39:00 to 15-JUL-22 17:39:00 (MST-7)
Location: ROCK SPGS
Magnitude: 56.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Thunderstorm Wind in ROSEBUD, MONTANA
From 15-JUL-22 17:59:00 to 15-JUL-22 17:59:00 (MST-7)
Location: FORSYTH
Magnitude: 56.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet