Common weather terms defined

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WATCH

A watch is used when the risk of a hazardous weather has increased significantly, but its occurrence, location, and/or timing is still uncertain. It is intended to provide enough lead time so that those who need to set their plans in motion can do so.


WARNING

A warning is issued when a hazardous weather is occurring or is imminent. A warning is used for conditions posing a threat to life or property.


SEVERE THUNDERSTORM

For a thunderstorm to be classified as severe, it must have winds of at least 58 mph (50 knots), and/or hail at least 3/4 inches in diameter or produce a tornado.


FUNNEL CLOUD

A condensation funnel extending from the base of a towering cumulus or Cb, associated with a rotating column of air that is not in contact with the ground (and hence different from a tornado).


TORNADO

A violently rotating column of air, usually pendant to a cumulonimbus, with circulation reaching the ground. It nearly always starts as a funnel cloud and may be accompanied by a loud roaring noise. On a local scale, it is the most destructive of all atmospheric phenomena.


TORNADO WARNING

This is issued when a tornado is indicated by radar or sighted by spotters.

A “Doppler Radar indicated” tornado does not necessarily mean that a tornado is on the ground.  The radar is detecting rotation within the storm which could spawn a tornado.

--Compiled by Storm Team 10 Meteorologist Sandra Brogan