Several rounds of rain and thunderstorms affected much of Montana during the first half of June. Flash flooding occurred across portions of the region, especially across Fergus County as well as the Rocky Mountains. Fergus County was hit exceptionally hard as several days of occasional heavy rain exasperated area creeks and streams. Casino Creek, located south of Lewistown, was washed out in at least two locations with significant road repairs required. Cottonwood Creek to the west of Casino Creek completely washed out Cotton Creek Road in several areas. Across the Rocky Mountains, easterly flow compressed moisture along the Rocky Mountain Front Range resulting in heavy rainfall and thunderstorms. Several debris flows were reported. Portions of Glacier National Park were temporarily closed due to rock slides and debris flows. The Helena-Lewis and Clark National Forest also reported several flooding impacts. Across Meagher and Broadwater Counties, heavy rain affected the Woods Creek and Deep Creek burn scar areas, resulting in flash flooding along Highway 12. Flash flooding also occurred just south of Great Falls along Wilson Butte Road from a rapidly developing thunderstorm that produced 1.37 inches of rain in less than an hour at a NWS employee's home along Wilson Butte Road. A brief tornado also occurred across rural Hill County and was greatly photographed, but no damage was reported.

Flash Flood in MEAGHER, MONTANA
From 10-JUN-23 13:14:00 to 10-JUN-23 15:00:00 (MST-7)
Location: WHITE SULPHUR SPGS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Meagher County Sheriff's office reported that a portion of Highway 360 west of White Sulphur Springs was closed due to flooding on the roadways.

Flash Flood in LEWIS AND CLARK, MONTANA
From 10-JUN-23 15:45:00 to 10-JUN-23 17:00:00 (MST-7)
Location: MARYSVILLE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Spotter reported water flowing across several secondary roads as well as culverts flooding.

Debris Flow in TETON, MONTANA
From 08-JUN-23 13:30:00 to 08-JUN-23 18:00:00 (MST-7)
Location: BYNUM
Flood cause: Heavy Rain
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Park/Forest Service

The Helena-Lewis and Clark National Forest submitted a video showing South Fork Teton Road experiencing washouts and debris flows.

Debris Flow in GLACIER, MONTANA
From 08-JUN-23 17:20:00 to 08-JUN-23 18:00:00 (MST-7)
Location: KIOWA
Flood cause: Heavy Rain
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Park/Forest Service

Glacier National Park reported that portions of Montana Highway 49 and the Looking Glass  Highway were closed due to debris flows from heavy rain.

Debris Flow in LEWIS AND CLARK, MONTANA
From 08-JUN-23 14:02:00 to 08-JUN-23 18:00:00 (MST-7)
Location: AUGUSTA ARPT
Flood cause: Heavy Rain
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Park/Forest Service

A significant debris flow crossed Benchmark Road, west of Ford Creek, resulting in the road being impassable from debris and damage.

Flood in LEWIS AND CLARK, MONTANA
From 08-JUN-23 08:00:00 to 09-JUN-23 08:00:00 (MST-7)
Location: MID CANON
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Park/Forest Service

The Mid-Canon fishing access site near Craig was closed due to flooding by high river levels along the Missouri River.

Funnel Cloud in HILL, MONTANA
From 10-JUN-23 12:30:00 to 10-JUN-23 12:40:00 (MST-7)
Location: BOX ELDER
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public submitted photos of a funnel cloud near Rocky Boy, taken from Highway 87.

Tornado in HILL, MONTANA
From 10-JUN-23 13:09:00 to 10-JUN-23 13:15:00 (MST-7)
Location: BOX ELDER
Tornado F-scale: EFU
Reported by: Broadcast Media

Broadcast media submitted photos of tornado across rural Hill County. Two additional funnel clouds were filmed near the ongoing tornado. Due to limited access to the touchdown area, no storm survey was able to be conducted. Movement was to the west/northwest and was associated with a strengthening thunderstorm.

Flash Flood in CASCADE, MONTANA
From 05-JUN-23 17:54:00 to 05-JUN-23 19:00:00 (MST-7)
Location: FIELDS
Flood cause: Heavy Rain
Property damage: 50.00K
Crop damage: 20.00K
Reported by: NWS Employee

Water and debris rushed across several areas of Wilson Butte Road resulted in damage and impacts. Water flowed out of the rockier boulder terrain on the east side of the road, crossed the road with water depth being 2 to 3 feet deep at times. Water and debris entered at least two homes. One culvert was completely washed out with drainage pipes unearthed. Some wheat crops were flattened. NWS Employee that lives along the road had water enter their basement. Wilson Butte Road was impassable for approximately an hour.

Funnel Cloud in TETON, MONTANA
From 05-JUN-23 17:07:00 to 05-JUN-23 17:17:00 (MST-7)
Location: DUTTON ARPT
Reported by: Official NWS Observations

A non impactful funnel cloud was visible from several miles away, including the NWS office.

Hail in CASCADE, MONTANA
From 05-JUN-23 18:19:00 to 05-JUN-23 18:20:00 (MST-7)
Location: (GFA)MALMSTROM AFB
Magnitude: 1.00 
Reported by: NWS Employee

Employee reported one inch hail on southeast side of Great Falls. Started off as small hail.

Thunderstorm Wind in JUDITH BASIN, MONTANA
From 08-JUN-23 19:20:00 to 08-JUN-23 19:20:00 (MST-7)
Location: GEYSER
Magnitude: 59.00 MG
Reported by: Mesonet

Measured at site MTGYS near Geyser.

Flash Flood in FERGUS, MONTANA
From 07-JUN-23 13:55:00 to 07-JUN-23 15:30:00 (MST-7)
Location: (LWT)LEWISTON MUNI A
Flood cause: Heavy Rain
Property damage: 200.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Fergus County Sheriff's Office and Emergency Management reported portions of Casino Creek Road washed out from heavy rain and flooding of the creek. The road was washed out completely in at least two locations, per a later NWS survey. Many cattle fields along the creek were also flooded.

Flash Flood in FERGUS, MONTANA
From 07-JUN-23 14:00:00 to 07-JUN-23 15:30:00 (MST-7)
Location: GLENGARRY
Flood cause: Heavy Rain
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Fergus County Sheriff's Office reported portions of Cottonwood Creek Road washed out from flooding.

Flash Flood in BROADWATER, MONTANA
From 10-JUN-23 13:00:00 to 10-JUN-23 14:00:00 (MST-7)
Location: TOWNSEND ARPT
Flood cause: Heavy Rain / Burn Area
Property damage: 100.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Portions of N Creek Road as well as Highway 12 were closed due to debris flows and flash flooding in the Deep Creek Burn Scar area. The Deep Creek Picnic area was closed for over two months as a result of the flooding.