LIVE: Kristen’s Classroom: Tornado classification

Meteorologist Kristen Currie goes in-depth on the new findings of the U.S.' latest EF-5 tornado and why rating tornado strength is so different than other weather phenomena.

EF5 tornado that killed 3 in North Dakota was the nation’s first in 12 years

Meteorologists from the National Weather Service office in Grand Forks estimated the tornado’s winds reached 210 mph, ...