An upper-level ridge of hot temperatures and a lee surface trough brought scattered, mainly-dry thunderstorms to the area, some of which produced severe downburst winds and stronger gusts as it moved eastward across northeast Montana. As this gust front approached the Montana/North Dakota border, it met more unstable air, and strengthened into a line of severe thunderstorms.

Hail in PETROLEUM, MONTANA
From 10-JUL-17 14:10:00 to 10-JUL-17 14:10:00 (MST-7)
Location: FLATWILLOW
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A trained spotter reported penny sized hail in addition to heavy rainfall and wind gusts up to approximately 50 mph.

Thunderstorm Wind in DAWSON, MONTANA
From 10-JUL-17 18:10:00 to 10-JUL-17 18:10:00 (MST-7)
Location: GLENDIVE
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Thunderstorm winds uprooted a tree in the yard of a home in Glendive. The report was received via social media. Based on the photograph, the tree appeared to be approximately 18 inches in diameter at the base with a relatively shallow root system. The estimated wind speed is 60 mph.

Thunderstorm Wind in PHILLIPS, MONTANA
From 10-JUL-17 14:45:00 to 10-JUL-17 14:45:00 (MST-7)
Location: MALTA SOUTH DOT
Magnitude: 51.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

The Malta South US-191 DOT site measured a 59 mph wind gust.

Thunderstorm Wind in PETROLEUM, MONTANA
From 10-JUL-17 14:41:00 to 10-JUL-17 14:41:00 (MST-7)
Location: DRY BLOOD CREEK RAWS
Magnitude: 55.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: RAWS

The Dry Blood Creek RAWS site reported a wind gust of 63 mph.

Thunderstorm Wind in GARFIELD, MONTANA
From 10-JUL-17 15:08:00 to 10-JUL-17 15:08:00 (MST-7)
Location: SOUTH SAWMILL RAWS
Magnitude: 59.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: RAWS

The South Sawmill Creek RAWS site measured a 68 mph wind gust.

Thunderstorm Wind in GARFIELD, MONTANA
From 10-JUL-17 15:42:00 to 10-JUL-17 15:42:00 (MST-7)
Location: JORDAN AIRPORT (KJDN)
Magnitude: 52.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

A 60 mph wind gust was measured at the Jordan ASOS site.

Thunderstorm Wind in VALLEY, MONTANA
From 10-JUL-17 15:44:00 to 10-JUL-17 15:44:00 (MST-7)
Location: KING COULEE RAWS
Magnitude: 57.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: RAWS

The King Coulee RAWS site measured a 66 mph wind gust.

Thunderstorm Wind in GARFIELD, MONTANA
From 10-JUL-17 16:00:00 to 10-JUL-17 16:00:00 (MST-7)
Location: VAN NORMAN
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A trained spotter reported sustained winds of approximately 40 mph with gusts to approximately 60 mph. Blowing dust was reducing visibility to less than 1/2 mile with the stronger gusts.

Thunderstorm Wind in GARFIELD, MONTANA
From 10-JUL-17 16:08:00 to 10-JUL-17 16:08:00 (MST-7)
Location: SOUTH SAWMILL RAWS
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: RAWS

The South Sawmill RAWS site measured a 58 mph wind gust.

Thunderstorm Wind in VALLEY, MONTANA
From 10-JUL-17 16:10:00 to 10-JUL-17 16:10:00 (MST-7)
Location: GLASGOW
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

A NWS employee reported 3/4 inch diameter tree branches down due to thunderstorm outflow winds. Time is estimated based on radar.

Thunderstorm Wind in VALLEY, MONTANA
From 10-JUL-17 16:22:00 to 10-JUL-17 16:22:00 (MST-7)
Location: GLASGOW
Magnitude: 51.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

A 59 mph wind gust was measured at the Glasgow International Airport ASOS site.

Thunderstorm Wind in VALLEY, MONTANA
From 10-JUL-17 16:27:00 to 10-JUL-17 16:27:00 (MST-7)
Location: GLASGOW
Magnitude: 61.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

A Mesonet station in West Glasgow measured sustained winds of 56 mph, with a wind gust of 70 mph.

Thunderstorm Wind in VALLEY, MONTANA
From 10-JUL-17 16:44:00 to 10-JUL-17 16:44:00 (MST-7)
Location: KING COULEE RAWS
Magnitude: 56.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: RAWS

A 65 mph wind gust was measured at the King Coulee RAWS site.

Hail in WIBAUX, MONTANA
From 10-JUL-17 18:45:00 to 10-JUL-17 18:45:00 (MST-7)
Location: ST PHILLIP
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

A motorist reported quarter size hail on Montana Highway 7 approximately 10 miles south of Wibaux. The report was received via social media.

Thunderstorm Wind in WIBAUX, MONTANA
From 10-JUL-17 18:45:00 to 10-JUL-17 18:45:00 (MST-7)
Location: ST PHILLIP
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

A motorist reported wind gusts of approximately 60 mph on Montana Highway 7 approximately 10 miles south of Wibaux. The report was received via social media.