Overview

• The National Weather Service in Grand Forks announced the EF-5 rating on October 6 after reanalyzing the June 20 storm.
• Meteorologists estimated peak winds exceeded 210 mph, meeting the highest tier of the Enhanced Fujita scale.
• The tornado killed three people, cut a path just over 12 miles long, and reached a maximum width of about 1.05 miles.
• Key evidence included 33 derailed train cars with several fully loaded grain hoppers tipped, an empty tanker thrown roughly 475 feet, debarked and uprooted trees, and a farmstead swept from its foundation.
• The storm occurred during a broader outbreak and derecho that produced 100-plus mph winds across North Dakota and western Minnesota, complicating initial surveys and delaying the final rating.