Thunderstorm Wind in Morton County, North Dakota

A large fertilizer building north of New Salem sustained heavy damage from extreme straight line winds associated with a severe thunderstorm. Visual inspection of the damage conducted during a storm survey indicates estimated winds of 95 mph. Much of the damage was to the roof of the building, in which much of the metal roof was peeled back and blown off to the north. Preliminary damage was estimated at over one million dollars to the building and loss of fertilizer.

Additional damage from severe thunderstorm winds was observed north-northeast of New Salem towards the Morton County and Oliver County border. Several farms had damage to outbuildings, trees, and farm equipment. Damage here was estimated at one quarter of a million dollars.

A surface warm front continued to lift slowly north across southern North Dakota during the day on Monday, May 24th, in advance of a potent upper level trough racing northeast across the Rocky Mountains and towards the Northern Plains. Tornado Watch number 215 was issued by mid afternoon in anticipation of rapid thunderstorm development and intensification once mass divergence associated with the upper wave spread across the region. An elevated threat for tornadoes existed along the warm front due to favorable low level vertical shear parameters.

Numerous severe thunderstorm and tornado warnings were issued from late in the afternoon till later in the evening. Several reports of large hail, multiple reports of severe thunderstorm winds, and several reports of funnel clouds and tornadoes were received during this event. The number of confirmed tornadoes was two.