The most rare and extreme form of tornado struck eastern North Dakota in June, but experts just determined how strong it really was.

Meteorologists say a deadly tornado in North Dakota this summer has been upgraded to a top-of-the-scale EF5, and was the ...

A 12-year "drought" of EF5 tornadoes has ended, after the National Weather Service upgraded a tornado in North Dakota to EF5 status.

A powerful tornado struck Enderlin, North Dakota, on June 20, causing significant damage and leading to a rare EF5 ...

The National Weather Service said the EF5 twister in North Dakota packed winds stronger than 200 mph, underscoring risks that ...

The storm, which killed three people and tossed train cars hundreds of feet, was nearly a mile wide and carved a 12-mile path ...

The first EF5 tornado was confirmed in North Dakota, here's a history and the last F5 tornadoes to hit Michigan.

What they're saying: "In the last kind of 12 years, there's been several strong tornadoes that have come close, but there haven't been known damage indicators at that time to support the EF5 rating," ...

A deadly tornado that tore across southeastern North Dakota this summer has been upgraded to an EF5 with winds topping 200 mph, the strongest classification of tornado and the first confirmed on ...

A deadly tornado that tore across southeastern North Dakota this summer has been upgraded to an EF5 with winds topping 200 ...

A deadly tornado that tore across southeastern North Dakota this summer has been upgraded to an EF5 with winds topping 200 mph, the strongest classification of tornado and the first on American soil ...

A deadly tornado that tore across southeastern North Dakota this summer has been upgraded to an EF5 with winds topping 200 mph (322 kph), the strongest classification of tornado and the first ...