Northeast Montana Severe Weather Event
June 16, 2007 |
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| Discussion: |
| During the early afternoon and into the evening of June 16, 2007, a high precipitation supercell thunderstorm tracked
from far northern Montana east to the North Dakota State line. This storm was the most devastating hailstorm to affect the
Glasgow area since at least 1999, and prompted 22 severe thunderstorm and 6 tornado warnings in the NWS Glasgow county
warning area. |
| The storm began prior to noon just east of Glacier National Park and gradually moved hundreds of miles eastward
through the day. Just before 3 pm, the storm produced a funnel cloud between the towns of Harlem and Zurich in
Blaine county. This storm then proceeded into the NWS Glasgow area in Phillips County while making a turn
to the southeast. Hail up to baseball size and wind gusts in excess of 85 mph were later reported as the
supercell tracked across Valley and northern McCone counties. Torrential heavy rainfall was also experienced,
prompting seven flash flood warnings to be issued. The large hail left a hail swath seen on GOES and Terra MODIS
satellites that had a path at least 225 miles long, and up to 12 miles wide. The storm eventually weakened in
eastern Richland County, close to the North Dakota border, a little before 10 pm. By this point the supercell
had covered approximately 300 miles in nearly 10 hours. |
| The most significant damage from the storm occurred in portions of Valley and McCone Counties. The towns of Glasgow
and Nashua, both in Valley County, took a direct hit from the storm. In Glasgow, inflow winds out of the southeast
had gusted to 60 to 65 mph ahead of the storm bringing down several small tree limbs. These winds then switched to
the northwest with gusts in excess of 70 mph accompanied by golfball to baseball size hail. The hail fell for
several minutes before diminishing to penny size for another 10-20 minutes. The majority of the
homes and businesses in Glasgow had some sort of damage including: broken windows, damaged shingles, dented or
broken gutters and skirting. Many vehicles also had significant hail damage. Just the property damage alone in
Glasgow amounted to nearly $8.0 million. As the storm continued east it impacted the town of Nashua and every home and
business had some form of damage from the baseball size hail and the damaging winds that occurred with it. The winds
were measured at 89 mph just west of town. Property damage in Nashua was estimated to be $3 million. In rural
areas outside of Glasgow and Nashua there were several cottonwood trees completely uprooted. Horses and cattle were
injured by the hail and wind, and Montana Fish, Wildlife and Parks reported many birds and small animals were killed
by the hail. There were thousands of acres of alfalfa, wheat, and corn that were completely destroyed. Preliminary
damage estimates to crops alone in Valley County total $20 million. |
| The storm also produced heavy rainfall of 1 to 2 inches, and was followed later in the evening by additional heavy
rain. Rainfall of 2 to 7 inches fell in the Antelope, Brazil and Willow Creek basins. The Antelope Creek basin had
its most significant flood on record and one road was completely underwater for nearly a third of a mile. One ranch
was isolated by the flood waters for three days. As the storm continued across northern McCone County and into
western Richland County it continued to produce hail up to the size of ping pong balls and wind gusts that were
estimated as high as 80 to 90 mph knocked down telephone and electrical poles. There was significant damage to farms
and ranches in the Vida area, as well as significant loss of crops, estimated at $5 million. The rural nature
of the area minimized the property damage that could have occurred. The overall estimated damage in this storm
between the hail and wind damage, and the subsequent flooding is 34.2 million dollars. |
| Photos: |
Storm as viewed from NWS-Glasgow |
Hail-damaged house in Nashua |
Flooded ranch along Antelope Creek |
Hail-damaged car |
Satellite view before the storm |
Satellite view after the storm showing a large hailswath |
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