EF3 Tornado — La Moure, North Dakota

2011-07-17 · near Nortonville, La Moure, North Dakota

Event narrative

A National Weather Service storm survey confirmed that an EF3 tornado touched down around seven miles southeast of Nortonville, then moved southeast before lifting six miles south southeast of Berlin. This was a long tracked tornado across parts of Russell, Wano, Henrietta, and Badger townships. Damage was observed all along the tornado path, with no fewer than five farmsteads impacted, some very severely. One injury occurred where a farm home was damaged beyond repair. There were no deaths. The worst damage consisted of a farm house completely destroyed, outbuildings completely destroyed, a vehicle tossed up to one half mile away from its original location and almost unrecognizable as a motor vehicle, and a significant number of very large hard and soft wood trees both snapped and uprooted. The violent nature of tornadoes was evidenced by the twisted and mangled trees. In one case farm animals were killed. The tornado damage corresponded to EF3 on the Enhanced Fujita Scale. From that it was determined that wind speeds were on the order of 165 miles per hour.

Wider weather episode

A prolonged severe weather event materialized July 17th with an extremely unstable atmosphere present and supportive mid level dynamics. The first wave of storms occurred from the mid morning through the early afternoon hours as a short wave mid level impulse crested the central plains upper ridge across North Dakota. Storms intensified ahead of this feature, prompting the issuance of several severe thunderstorm and tornado warnings. Numerous reports of large hail and severe thunderstorm wind gusts were received. In addition, 3 confirmed tornadoes occurred with this first wave.

The second wave occurred from the mid afternoon through the mid evening hours. This mainly consisted of one supercell thunderstorm. Severe weather reports included very large hail, strong winds, and two confirmed tornadoes. This included an EF3 tornado in Lamoure County.

View location on OpenStreetMap → (46.4900, -98.6300)

Source: NOAA Storm Events Database, event_id 331480. Narrative written by the NWS forecast office that issued the report.