GREAT FALLS — A tornado touched down in northeastern Montana on Thursday evening.
The tornado was likely on the ground in western Daniels County and eastern Valley County to the south of Richland and to the west of Peerless (northeast of Glasgow and southwest of Scobey).
With the area being flat it allowed the tornado to be viewed from a far distance as it was seen at least as far east as Scobey and as far north as Canada.
The tornado touched down in a very rural area, so most of the damage likely occurred to farmland. Also, since it did occur in a rural area, it is harder to determine by photos how strong the tornado was, but it was likely an EF-0 or an EF-1.
The National Weather Service in Glasgow will likely send out a team to do a damage survey on Friday, and that should provide us with more information on the tornado, including where exactly it was on the ground, how long it was on the ground, and how strong it was.
At this point, there are no reports of any injuries or property damage.
Unlike those in "Tornado Alley" in the central part of the country, most Montana tornadoes are relatively small and usually touch down in sparsely-populated areas – but not always.
In 2016, an EF-3 tornado hit the town of Baker in southeast Montana. In 2015, a small tornado hit near Sidney in Richland County in eastern Montana, injuring one person and causing some damage. In June 2010, a tornado hit Billings, causing significant damage to the MetraPark facility. Just several weeks later, two people were killed when a tornado struck a family ranch near Reserve in northeastern Montana.
Montana's tornado season generally spans from late May through early August. The two key ingredients for tornado formation are low-level moisture and wind shear.
Wind shear is the change in wind direction with height up to the mid-levels of the atmosphere.
Patrick Gilchrist, the warning coordination meteorologist for the National Weather Service in Glasgow, said, "When it comes to tornadoes in Montana, it's really about moisture. So to get tornado development, we really want a moist layer right at the surface of the Earth at the lowest levels. That is provided actually by the Gulf of Mexico."
The likelihood of tornadoes increases in eastern Montana, due to the proximity to the Gulf of Mexico, not the change in topography. Higher terrain in western Montana actually acts as ignition for severe weather outbreaks as it forces the air to move vertically creating lift in the atmosphere. The severe weather outbreaks can often last through the night, traveling as far as Minnesota.
While tornadoes are less common in central Montana, the threat still exists. There have been a few notable events in recent history. An F2 moved through Lewistown back in 1999 and a series of F3 tornadoes southeast of Big Sandy in Chouteau County back in 1988.
The Enhanced Fujita Scale replaced the Fujita Scale in February 2007.
Damage assessments are utilized in determining the tornado scale, which can be difficult given the rural nature of eastern Montana.