The storm shaped like a funnel and capable of devastating damage when it reaches the ground is a tornado.
A tornado is a violently rotating column of air extending from a thunderstorm to the ground. Its visible funnel is made of condensed water droplets, dust, and debris; the circulation can be wider than the portion that is visible. A funnel cloud becomes a tornado when its rotating column makes contact with the surface.
Tornadoes form most often in severe thunderstorms, especially supercells, when warm, humid air meets cooler, drier air and winds change speed or direction with height. The United States records more tornadoes than any other country, although they occur on every continent except Antarctica.
The Fujita scale, introduced in 1971, classified tornado damage from F0 to F5. The United States replaced it with the Enhanced Fujita scale in 2007, which estimates wind intensity from damage indicators. Hurricanes and tornadoes are different storms: hurricanes are enormous ocean-born systems, while tornadoes are much smaller and usually short-lived.