After a period of quiet weather, several days of strong to severe thunderstorms occurred during the latter part of July. Chinook was struck the hardest with up to baseball size hail resulting in significant vehicle and structural damage. Harlem and Fort Belknap also received severe hail. Additional severe storms impacted the east side of Great Falls, Belt, and Lewistown with large hail being reported in all three locations.

Hail in GALLATIN, MONTANA
From 28-JUL-23 15:16:00 to 28-JUL-23 15:24:00 (MST-7)
Location: SEDAN
Magnitude: 1.75 
Reported by: Social Media

Several reports of hail ranging from dime size to golf ball. Hail accumulated on MT Highway 86, resulting in some impacts to drivers.

Hail in BLAINE, MONTANA
From 30-JUL-23 20:09:00 to 30-JUL-23 20:16:00 (MST-7)
Location: FT BELKNAP AGENCY
Magnitude: 1.25 
Reported by: COOP Observer

Co-op observer reported hail of quarter size was covering the ground.

Thunderstorm Wind in HILL, MONTANA
From 30-JUL-23 18:20:00 to 30-JUL-23 18:20:00 (MST-7)
Location: FRESNO
Magnitude: 55.00 MG
Reported by: Mesonet

Recorded by automated system on southeast end of Fresno Reservoir.

Hail in GALLATIN, MONTANA
From 28-JUL-23 15:33:00 to 28-JUL-23 15:41:00 (MST-7)
Location: SEDAN
Magnitude: 1.75 
Reported by: Trained Spotter

Spotter northwest of Wilsall reported golf ball size hail and estimated wind gusts of 70 mph.

Hail in CASCADE, MONTANA
From 29-JUL-23 17:54:00 to 29-JUL-23 18:05:00 (MST-7)
Location: WAYNE
Magnitude: 1.75 
Reported by: Social Media

Reports on social media of vehicles in Wayne being dented from large hail.

Hail in FERGUS, MONTANA
From 29-JUL-23 20:13:00 to 29-JUL-23 20:16:00 (MST-7)
Location: LEWISTOWN
Magnitude: 1.25 
Reported by: Social Media

Pictures submitted of hail in Lewistown slightly larger than one inch.

Hail in FERGUS, MONTANA
From 29-JUL-23 20:15:00 to 29-JUL-23 20:18:00 (MST-7)
Location: (LWT)LEWISTON MUNI A
Magnitude: 1.00 
Reported by: Trained Spotter

Spotter reported one inch hail.

Hail in CASCADE, MONTANA
From 30-JUL-23 18:47:00 to 30-JUL-23 18:50:00 (MST-7)
Location: (GFA)MALMSTROM AFB
Magnitude: 1.25 
Reported by: Other Federal Agency

Malmstrom AFB personnel reported half dollar size hail occurring on base.

Hail in CASCADE, MONTANA
From 30-JUL-23 19:08:00 to 30-JUL-23 19:11:00 (MST-7)
Location: BELT
Magnitude: 1.00 
Reported by: Trained Spotter

Spotter reported quarter size hail in Belt.

Hail in BLAINE, MONTANA
From 30-JUL-23 19:27:00 to 30-JUL-23 19:31:00 (MST-7)
Location: CHINOOK
Magnitude: 2.00 
Property damage: 1.00M
Reported by: Insurance Company

Several photos submitted on social media of large hail in Chinook. Insurance company reported at least 11 vehicle hail damage claims and 5 homeowners claims.  Number of claims likely increased since preliminary reports.

Hail in BLAINE, MONTANA
From 30-JUL-23 19:29:00 to 30-JUL-23 19:37:00 (MST-7)
Location: CHINOOK
Magnitude: 2.50 
Reported by: Social Media

Photos submitted of hail being measured with a ruler as well as being compared to coins.

Hail in BLAINE, MONTANA
From 30-JUL-23 19:17:00 to 30-JUL-23 19:27:00 (MST-7)
Location: CHINOOK
Magnitude: 1.75 
Reported by: Emergency Manager

Blaine County Deputy EM reported golf ball size hail at their property.

Hail in BLAINE, MONTANA
From 30-JUL-23 20:08:00 to 30-JUL-23 20:14:00 (MST-7)
Location: HARLEM
Magnitude: 1.50 
Reported by: Social Media

Images submitted of large hail in Harlem.