There were several tornadoes in northeastern Montana Friday evening (July 12, 2024).
It will take a few days for the National Weather Service in Glasgow to investigate and issue a report on Friday’s heavy rain, but from the photos we have received, it appears there were at least three tornadoes, if not more.
Twin tornadoes occurred south-southeast of Opheim in Valley County, and a tornado occurred in Daniels County south of the Richland area. There was also a possible tornado near Larslan in Valley County.
The first tornado warning was issued at 6:47 p.m. for the northern portion of Valley County, with the last tornado warning expiring at 8:15 p.m.
Tornado warnings were in effect for northeastern Valley County, southwestern Daniels County and northwestern Roosevelt County during that 88-minute period.
It appears that most of the tornadoes occurred in rural areas, so most of the damage was limited to farmland. However, there were reports of broken trees, downed power lines, and a barn being torn off near the Larslan area. It appears that the Larslan area suffered the most damage.
MTN News
Tornadoes weren’t the only threat from these storms: there was also torrential rain, strong winds with gusts up to 60 mph and large hail.
One viewer reported that baseball- or softball-sized hail fell north of Larslan, and our radar indicated that grapefruit-sized hail may have fallen at one point.
We will update this article with more information as we receive it. However, if you or anyone you know has photos or videos of the tornadoes, hail or any damage, please email [email protected].
TORNADOES IN MONTANA
Montana typically experiences about a dozen tornadoes per year. Unlike the tornadoes in “Tornado Alley” in the central part of the country, most of Montana’s tornadoes are relatively small and typically affect sparsely populated areas.
Tornadoes are classified according to the Enhanced Fujita (EF) scale from EF-0 to EF-5, depending on their destructive power. EF-0 tornadoes are the weakest, while EF-5 tornadoes are the most powerful.
In 2022, an EF-2 tornado struck the community of Glentana in Valley County, causing property damage (link). The tornado was on the ground for 8 miles (13 kilometers) and had an average path width of 1,300 feet (420 meters). The maximum wind speed associated with this tornado was 120 miles (193 kilometers per hour).
Valley County Resident
In 2016, an EF-3 tornado struck the town of Baker in southeastern Montana. In 2015, a small tornado struck near Sidney in Richland County in eastern Montana, injuring one person and causing damage.
In June 2010, a tornado struck Billings, causing significant damage to MetraPark. A few weeks later, two people were killed when a tornado struck a family ranch near Reserve in northeastern Montana.
Tornado season in Montana typically runs from late May to early August. The two main factors in tornado formation are low-level moisture and wind shear.
Wind shear is the change in wind direction with height up to mid-levels of the atmosphere.
Patrick Gilchrist, a warning coordination meteorologist with the National Weather Service in Glasgow, said, “When it comes to tornadoes in Montana, it’s all about moisture. For tornadoes to develop, we really need a layer of moisture right at the surface of the Earth, at the lowest levels. That’s what the Gulf of Mexico actually provides.”
Tornadoes are not common in Montana, but can strike
The probability of tornadoes increases in eastern Montana, due to the proximity of the Gulf of Mexico, not the change in topography. The higher terrain of western Montana actually favors severe storm events because it forces air to move vertically, creating lift in the atmosphere. Severe storm events can often last all night, extending as far as Minnesota.
Although tornadoes are less frequent in central Montana, the threat still exists. A few notable events have occurred in recent history. An F2 tornado tore through Lewistown in 1999 and a series of F3 tornadoes southeast of Big Sandy in Chouteau County in 1988.
Damage assessments are used to determine the extent of tornadoes, which can be difficult given the rural nature of eastern Montana.
