EF3 tornado in Rolette County, North Dakota

By North Dakota standards this was a long lived tornado that covered many miles.

A National Weather Service storm damage survey was completed in Rolette County on July 8, the day following the event. The storm survey concluded that the total path length was 17.6 miles, with a maximum width of 250 yards. The worst damage corresponded to low end EF3 on the Enhanced Fujita Scale, with maximum estimated winds of 140 mph.

Multiple tornado sightings were reported by local officials and residents along Bureau of Indian Affairs (BIA) Highway number eight between 2:50 PM CDT and 3:10 PM CDT. The storm survey concluded that tree and structural damage along this corridor west and northwest of Belcourt corresponded to EF1 and EF2 on the Enhanced Fujita scale, or wind speeds ranging from 90 to 130 mph, with a path width ranging from 50 to 75 yards. Greater damage was surveyed north and northeast of Belcourt. Along BIA Highway number seven, a tornado path width of 250 yards was observed with significant widespread tree damage, corresponding to an EF2 rating or winds of 115 to 130 mph. Northeast of Belcourt along BIA highway number five, a home sustained heavy damage and there was one injury. Here, a rating of EF2 was assigned, with estimated wind speeds up to 135 mph. Storm reports around the immediate Belcourt area indicate a time of approximately 3:15 PM CDT for tornado impact. Seventy structures in total were impacted in the Belcourt area with varying degrees of damage.

The tornadic storm continued east hitting the north side of the city of Rolla at approximately 3:30 PM CDT. Twelve homes were destroyed and 18 homes were damaged. The homes with the most significant structural damage corresponded to an EF3 rating. From this it was determined that the maximum wind speeds here were on the order of 140 mph. Two minor injuries were also reported in the Rolla area. The tornado continued east-southeast, hitting a farmstead east of Rolla which sustained structural and tree damage consistent with an EF2 tornado, or winds around 125 mph. The tornado then crossed US Highway 281 before pushing southeast into Towner County (See National Weather Service Grand Forks, North Dakota Storm Data from July 7, 2008).

In the early afternoon hours of Monday, July 7th, isolated thunderstorms developed over southwestern Manitoba, Canada, as a result of an upper level short wave trough tracking east across south central Canada. Maximized low level wind shear along a surface boundary over north central North Dakota, along with low lifted condensation levels, created a favorable environment for low level mesocyclones and the development of isolated tornadoes.

The end result was a tornadic supercellular thunderstorm developing near Lake Metigoshe. It tracked east-southeast through northeastern Bottineau County and across northern Rolette County, before exiting into Towner County (Grand Forks, North Dakota County Warning Area) later in the afternoon. A storm survey conducted the following day found tornado damage in the Belcourt and Rolla areas, with the heaviest damage observed on the north side of Rolla. There were injuries from the tornadoes, but there were no deaths. Estimated damage was around one and a half million dollars.