Thunderstorm Wind in LaMoure County, North Dakota

Extreme straight line winds associated with a severe thunderstorm caused extensive damage north of Kulm. Visual inspection of storm survey photos indicate estimated winds of 90 to 105 mph. The worst damage and highest estimated winds occurred roughly 2 miles north-northwest of Kulm where 4 large grain bins were destroyed and heavy damage was sustained to a shop on a farmstead. Also, one wall was destroyed and the roof collapsed on a large machine shed, and several pieces of farm machinery had damage from being blown over. Preliminary damage estimates indicated one million dollars to this one location. Other areas north of Kulm also sustained damage from the straight line wind gusts, but not as severe.

Thunderstorm winds in the Marion area caused extensive damage, especially to the grain handling complex in the city of Marion. Two large steel grain bins became detached from their footings, with one moving about 100 yards. The top of the grain elevator which contained the distribution portion of the grain moving legs was blown off. Multiple roofs were damage, spruce trees were uprooted, and power lines broken. The loss of power led to a secondary impact with sump pumps shutting down and basements taking on water.

The most severe wind damage observed during the storm survey in LaMoure County occurred in the town of Grand Rapids. Significant and widespread tree damage was observed, including numerous mature hardwood trees uprooted or snapped in half. Damage was also sustained to buildings, which consisted of roof damage, damage to pole barns, and several grain bins destroyed. Hey bales of 1300 pounds were also blown up to 500 yards across farm fields. ||The peak estimated wind speed of 105 mph was assigned based on damage indicators from the Enhanced Fujita Scale. It was later learned that wind sensing instruments on wind towers 10 miles west of Edgeley recorded a peak wind gust of 103 mph during the storm.