National Weather Service United States Department of Commerce

FUNNEL CLOUD - a funnel-shaped cloud extending downward from the base of a thunderstorm which is rapidly rotating and does NOT come into contact with the ground or objects on the ground.

 

SEVERE THUNDERSTORM - a thunderstorm which produces:

hail 1 inch or greater

winds greater than 58 mph

damage to trees, telephone/utility poles or any structure

tornado

 

TORNADO - a funnel-shaped cloud extending downward from the base of a severe thunderstorm which is rapidly rotating and comes into contact with the ground or any objects on the ground.
 

TORNADO WATCH - issued by the Storm Prediction Center when severe thunderstorms may produce tornadoes and near the watch area (box). The watch is issued for a large area and is usually in effect for several hours.
 

TORNADO WARNING - issued by your local NWS Forecast Office when a tornado is imminent or occurring and is usually in effect for 45 minutes or less.

 

WATERSPOUT - a tornado that occurs over the waters.