Warm, moist air and a very unstable atmosphere combined with a trough of low pressure moving through the area to form and sustain multiple severe thunderstorms across much of eastern Montana.

Hail in PRAIRIE, MONTANA
From 07-JUN-18 18:23:00 to 07-JUN-18 18:23:00 (MST-7)
Location: KAMM
Magnitude: 2.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

A storm chaser reported tennis ball size hail.

Flash Flood in DAWSON, MONTANA
From 07-JUN-18 18:30:00 to 07-JUN-18 18:30:00 (MST-7)
Location: RICHEY
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public reported streams running bankful and 1-2 feet of water running over a road.

Hail in DANIELS, MONTANA
From 07-JUN-18 19:40:00 to 07-JUN-18 19:40:00 (MST-7)
Location: FOUR BUTTES
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Multiple reports from the public, all confirming golf ball size hail.  Time estimated by radar.

Flash Flood in PRAIRIE, MONTANA
From 07-JUN-18 18:23:00 to 07-JUN-18 18:23:00 (MST-7)
Location: KAMM
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

A storm chaser reported water, several inches deep, flowing rapidly across Intersate 94.

Hail in DAWSON, MONTANA
From 07-JUN-18 18:30:00 to 07-JUN-18 18:30:00 (MST-7)
Location: RICHEY
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public reported half dollar size hail.

Hail in DAWSON, MONTANA
From 07-JUN-18 18:30:00 to 07-JUN-18 18:30:00 (MST-7)
Location: RICHEY
Magnitude: 1.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public reported ping pong ball size hail.  Time based on radar.

Hail in DAWSON, MONTANA
From 07-JUN-18 18:04:00 to 07-JUN-18 18:04:00 (MST-7)
Location: RICHEY
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

A storm chaser reported quarter size hail.

Hail in RICHLAND, MONTANA
From 07-JUN-18 18:59:00 to 07-JUN-18 18:59:00 (MST-7)
Location: ENID
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported half dollar size hail.

Hail in RICHLAND, MONTANA
From 07-JUN-18 19:13:00 to 07-JUN-18 19:13:00 (MST-7)
Location: ENID
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported half dollar size hail.

Thunderstorm Wind in RICHLAND, MONTANA
From 07-JUN-18 19:13:00 to 07-JUN-18 19:13:00 (MST-7)
Location: ENID
Magnitude: 70.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter measured an 80 mph wind gust.

Flash Flood in PRAIRIE, MONTANA
From 07-JUN-18 19:20:00 to 07-JUN-18 19:20:00 (MST-7)
Location: MC CLOUD
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public reported water up to 2 feet deep running swiftly over multiple roads.

Thunderstorm Wind in RICHLAND, MONTANA
From 07-JUN-18 19:21:00 to 07-JUN-18 19:21:00 (MST-7)
Location: ENID
Magnitude: 76.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

A Davis Pro weather station measured an 87 mph wind gust.  A barn on the property was completely leveled.

Hail in RICHLAND, MONTANA
From 07-JUN-18 19:21:00 to 07-JUN-18 19:21:00 (MST-7)
Location: ENID
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public reported half dollar size hail.

Thunderstorm Wind in RICHLAND, MONTANA
From 07-JUN-18 19:34:00 to 07-JUN-18 19:34:00 (MST-7)
Location: SIOUX PASS DOT
Magnitude: 72.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public reported an 83 mph wind gust measured at their ranch, across the Missouri River, south of Brockton.

Hail in ROOSEVELT, MONTANA
From 07-JUN-18 19:50:00 to 07-JUN-18 19:50:00 (MST-7)
Location: FT KIPP
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public reported quarter size hail.

Hail in ROOSEVELT, MONTANA
From 07-JUN-18 19:54:00 to 07-JUN-18 19:54:00 (MST-7)
Location: BROCKTON
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported half dollar size hail.

Flash Flood in DAWSON, MONTANA
From 07-JUN-18 19:40:00 to 07-JUN-18 19:40:00 (MST-7)
Location: RICHEY
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public reported multiple streams flooding and water up to 2 feet over a road.

Thunderstorm Wind in DANIELS, MONTANA
From 07-JUN-18 20:40:00 to 07-JUN-18 20:40:00 (MST-7)
Location: NAVAJO
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public estimated a 70 mph wind gust while their car was nearly blown off the road by strong crosswinds.

Hail in DANIELS, MONTANA
From 07-JUN-18 19:40:00 to 07-JUN-18 19:40:00 (MST-7)
Location: NAVAJO
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public reported quarter size hail.

Hail in DANIELS, MONTANA
From 07-JUN-18 19:40:00 to 07-JUN-18 19:40:00 (MST-7)
Location: FOUR BUTTES
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public reported golf ball size hail, leaving drifts up to 2 feet deep overnight.

Hail in SHERIDAN, MONTANA
From 07-JUN-18 20:20:00 to 07-JUN-18 20:20:00 (MST-7)
Location: PLENTYWOOD SHRWD ARP
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported quarter size hail.

Hail in DANIELS, MONTANA
From 07-JUN-18 20:40:00 to 07-JUN-18 20:40:00 (MST-7)
Location: FLAXVILLE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public reported a small amount of hail up to the size of quarters.

Hail in ROOSEVELT, MONTANA
From 07-JUN-18 20:05:00 to 07-JUN-18 20:05:00 (MST-7)
Location: POPLAR
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported, via social media, quarter size hail.

Hail in ROOSEVELT, MONTANA
From 07-JUN-18 20:07:00 to 07-JUN-18 20:07:00 (MST-7)
Location: FROID
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported half dollar size hail.

Hail in SHERIDAN, MONTANA
From 07-JUN-18 20:45:00 to 07-JUN-18 20:45:00 (MST-7)
Location: ANTELOPE
Magnitude: 1.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported ping pong ball size hail.

Hail in SHERIDAN, MONTANA
From 07-JUN-18 20:52:00 to 07-JUN-18 20:52:00 (MST-7)
Location: COMERTOWN DOT
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported quarter size hail.