Tornadoes are violent and rapidly rotating columns of air that form inside thunderstorms. They connect with the ground, via a funnel, to the cloud. Tornadoes typically last only a few minutes, but sometimes they can last for more than an hour. They can also travel short distances (0.5 miles), but some can be “on the ground” for upwards of 100 miles.
From 1950-2015, over 1,250 tornadoes have been recorded in North Carolina. While there has never been an EF-5 (winds over 200 mph) tornado in the state, there have been 12 EF-4 (166 - 200 mph) and 36 EF-3 (136 - 165 mph) rated tornadoes.
Source: TornadoHistoryProject.com
The tornado outbreak of April 16, 2011, is one of the biggest ever recorded in the state. There were 39 confirmed tornadoes on that date, with damage estimates over $350 million dollars. You can learn more about the event from this article provided by the State Climate Office of North Carolina.