Tornado in Divide County, North Dakota

Storm chaser reported brief tornado at this approximate location. No known damage to evaluate and no other information available. By National Weather Service policy the tornado is rated EF-U (Unknown).

A surface trough and low-level jet combined with a very moist and unstable air mass that led to severe thunderstorm development along the triple point of a surface low in west central North Dakota. Thunderstorms developed during the afternoon in southwest North Dakota, with additional storms in the far northwest. Storms gradually moved to the north-northeast through the evening in a primarily cluster storm mode. The area of most significant damage was in Ward and McHenry Counties. In the town of Sawyer in Ward County, the Emergency Manager reported damage from powerful thunderstorm wind gusts that resulted in power outages, trees on roads, and a large tree that fell onto a house and made a hole in the roof. Northeast of Deering in McHenry County, there was significant damage to a homestead due to thunderstorm wind gusts. A barn on the property had roof panels ripped off and some collapse of the wood frame structure for the roof. Damage in both of these locations were consistent with wind speeds around 90 mph. The largest reported hail was 3 inches in diameter, a few miles west of Fortuna in Divide County. One tornado occurred with these storms, and was reported approximately 3 miles east of Noonan in Divide County. It was a very brief tornado and caused no known damage, so has been rated EF-Unknown by NWS policy.