Two severe thunderstorms moved through Yellowstone County Montana on the evening of June 26, 2001. The first storm initiated over northwest Billings in about 15 minutes. The first storm formed a wall cloud and the Billings WSR-88D indicated rotation with this storm which prompted a tornado warning to be issued for the city of Billings. Quarter size hail was reported in the Alkali Creek area (west of Billings) and a 62 mph wind gust was observed at the Billings Airport. Several funnel clouds were reported by the public and law enforcement with this storm.	A second storm developed over Park City, Montana. This storm also formed a wall cloud which the Billings WSR-88D indicated as rotating. This storm also produced several funnel clouds, one of which was observed by a NWS meteorologist.  Quarter, Golf Ball, and Half Dollar sized hail was reported from Park City through the Laurel, Montana areas.  A new Tornado Warning was issued to cover both tornadic thunderstorms.  Two additional Tornado Warnings (continuation of previous warnings) were issued for Yellowstone County, Montana.  	Due to the extremely heavy rain and the slow movement of these thunderstorms, a Flash Flood Warning was issued for  Yellowstone County.  Rain reports from the Billings Airport was 0.66 inches in about 45 minutes.  Huntley, Montana received 1.67 inches of rain in just under 50 minutes.  Flash flooding was observed over much of eastern Yellowstone County including downtown Billings. 	Eventually the two separate supercells merged just east of Billings.  A Bow Echo evolved in this area and began moving east.  Ten 70 foot (2 foot diameter) power poles were blown down in Huntley, Montana and a semi-trailer was blown over.  Several 3 foot diameter trees were also blown down in Shepherd, Montana.  A WFO Billings Post-Storm Damage Survey Team assessed this damage and estimated the wind speeds that caused it to be 90 to 100 mph.

Hail in CARBON, MONTANA
From 26-JUN-01 19:25:00 to 26-JUN-01 19:25:00 (MST)
Location: SILESIA
Magnitude: 0.75 
Reported by: TRAINED SPOTTER

Hail in YELLOWSTONE, MONTANA
From 26-JUN-01 19:35:00 to 26-JUN-01 19:35:00 (MST)
Location: BILLINGS
Magnitude: 1.75 
Reported by: AMATEUR RADIO

Golf ball size hail

Thunderstorm Wind in YELLOWSTONE, MONTANA
From 26-JUN-01 20:46:00 to 26-JUN-01 20:46:00 (MST)
Location: WORDEN
Magnitude: 70 E
Reported by: TRAINED SPOTTER

Trees down

Hail in YELLOWSTONE, MONTANA
From 26-JUN-01 18:50:00 to 26-JUN-01 18:50:00 (MST)
Location: LAUREL
Magnitude: 2.00 
Reported by: TRAINED SPOTTER

Windows smashed and roof damaged

Hail in YELLOWSTONE, MONTANA
From 26-JUN-01 19:20:00 to 26-JUN-01 19:20:00 (MST)
Location: BILLINGS HGTS
Magnitude: 1.75 
Reported by: TRAINED SPOTTER

Golf ball size hail in western Alkali Creek

Flash Flood in YELLOWSTONE, MONTANA
From 26-JUN-01 20:36:00 to 26-JUN-01 20:36:00 (MST)
Location: BILLINGS LOGAN ARPT
Reported by: TRAINED SPOTTER

3 feet of water covering Shorey Road

Thunderstorm Wind in YELLOWSTONE, MONTANA
From 26-JUN-01 20:10:00 to 26-JUN-01 20:10:00 (MST)
Location: SHEPHERD
Magnitude: 90 E
Reported by: NWS STORM SURVEY

3 feet diameter trees down

Flash Flood in YELLOWSTONE, MONTANA
From 26-JUN-01 22:30:00 to 26-JUN-01 22:30:00 (MST)
Location: HUNTLEY
Reported by: NWS EMPLOYEE(OFF DUTY)

Water covering roadways

Thunderstorm Wind in YELLOWSTONE, MONTANA
From 26-JUN-01 20:20:00 to 26-JUN-01 20:20:00 (MST)
Location: HUNTLEY
Magnitude: 90 E
Reported by: NWS STORM SURVEY

10 power poles knocked down and semi-trailer knocked over

Flash Flood in YELLOWSTONE, MONTANA
From 26-JUN-01 20:30:00 to 26-JUN-01 20:30:00 (MST)
Location: BILLINGS
Reported by: TRAINED SPOTTER

Water over the road at 4th and 24th St. North

Thunderstorm Wind in YELLOWSTONE, MONTANA
From 26-JUN-01 19:25:00 to 26-JUN-01 19:25:00 (MST)
Location: BILLINGS LOGAN ARPT
Magnitude: 62 M
Reported by: AWOS,ASOS,MESONET,ETC

Hail in BIG HORN, MONTANA
From 26-JUN-01 20:30:00 to 26-JUN-01 20:30:00 (MST)
Location: HARDIN
Magnitude: 0.75 
Reported by: TRAINED SPOTTER

Flash Flood in YELLOWSTONE, MONTANA
From 26-JUN-01 20:25:00 to 26-JUN-01 20:25:00 (MST)
Location: BILLINGS
Reported by: TRAINED SPOTTER

6th Avenue flooded and closed

Thunderstorm Wind in YELLOWSTONE, MONTANA
From 26-JUN-01 20:45:00 to 26-JUN-01 20:45:00 (MST)
Location: POMPEYS PILLAR
Magnitude: 70 M
Reported by: AMATEUR RADIO

Construction equipment blown over on I-94

Flash Flood in YELLOWSTONE, MONTANA
From 26-JUN-01 21:00:00 to 26-JUN-01 21:00:00 (MST)
Location: BILLINGS
Reported by: LAW ENFORCEMENT

Montana and 1st Avenue South...water covering hoods of cars

Hail in YELLOWSTONE, MONTANA
From 26-JUN-01 18:30:00 to 26-JUN-01 18:30:00 (MST)
Location: LAUREL
Magnitude: 0.88 
Reported by: TRAINED SPOTTER

Flash Flood in YELLOWSTONE, MONTANA
From 26-JUN-01 20:18:00 to 26-JUN-01 20:18:00 (MST)
Location: BILLINGS
Reported by: TRAINED SPOTTER

1-2 miles north of K-Mart

Thunderstorm Wind in BIG HORN, MONTANA
From 26-JUN-01 21:00:00 to 26-JUN-01 21:00:00 (MST)
Location: HARDIN
Magnitude: 80 E
Reported by: TRAINED SPOTTER

80 mph thunderstorm wind gust...hay shed destroyed on Fly Creek Road

Hail in STILLWATER, MONTANA
From 26-JUN-01 19:30:00 to 26-JUN-01 19:30:00 (MST)
Location: PARK CITY
Magnitude: 0.75 
Reported by: LAW ENFORCEMENT

Hail in YELLOWSTONE, MONTANA
From 26-JUN-01 19:35:00 to 26-JUN-01 19:35:00 (MST)
Location: LAUREL
Magnitude: 1.25 
Reported by: TRAINED SPOTTER

Thunderstorm Wind in YELLOWSTONE, MONTANA
From 26-JUN-01 20:45:00 to 26-JUN-01 20:45:00 (MST)
Location: BALLANTINE
Magnitude: 70 M
Reported by: TRAINED SPOTTER

Road signs and construction debris on I-94

Hail in YELLOWSTONE, MONTANA
From 26-JUN-01 19:35:00 to 26-JUN-01 19:35:00 (MST)
Location: LAUREL
Magnitude: 1.00 
Reported by: TRAINED SPOTTER

Hail in STILLWATER, MONTANA
From 26-JUN-01 19:20:00 to 26-JUN-01 19:20:00 (MST)
Location: PARK CITY
Magnitude: 1.00 
Reported by: TRAINED SPOTTER

Hail drifted one foot deep. Windows broken on homes.