ENDERLIN, N.D. – An extensive forensic analysis of a deadly June tornado in North Dakota helped National Weather Service teams confirm the first EF-5 tornado in the U.S. in more than 12 years.
The tornado was part of a powerful derecho that brought twisters and 100-plus-mph wind gusts across North Dakota and western Minnesota from June 20-21, leaving a trail of damage and power outages across the region.
Three people were killed when a tornado swept through the rural town of Enderlin, North Dakota, according to the Cass County Sheriff's Office. Initial damage surveys gave the tornado a preliminary rating of EF-3 or stronger on the Enhanced Fujita Scale. Now, three months later, NWS teams with the Grand Forks office have completed the additional analysis to rate the deadly tornado an EF-5, the strongest on the tornado rating scale.
This marks the first EF-5 tornado in the U.S. since May 20, 2013, in Moore, Oklahoma.
According to the NWS final assessment, teams conducted additional surveys and worked with wind damage experts to estimate the Enderlin tornado's estimated wind speed was greater than 210 mph. An EF-5 tornado is classified as a twister with winds greater than 200 mph.
The tornado caused a train to derail south of Enderlin. Wind forensics helped determine the wind speed needed to tip several fully-loaded grain hopper cars and loft a tanker car. One empty tanker was tossed about 475 feet away, according to the report.
Damage to trees along the Maple River also contributed to the final rating. Investigators found trees with attached root balls ripped from the ground, including one where the original location wasn't found.
The Enderlin tornado covered a mile-wide path and destroyed property and landscapes across 12 miles, according to the NWS.
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