Knowra Funnel cloud Funnel cloud A visible, rotating funnel-shaped cloud extending from a thunderstorm that has not reached the ground. When its circulation reaches the surface, it is classified as a tornado.
Mesocyclone : A deep, rotating updraft within a thunderstorm, often associated with supercells. Many funnel clouds form beneath a mesocyclone as pressure falls within the storm’s rotating updraft.
Thunderstorm : A storm with lightning and thunder, produced by a cumulonimbus cloud. Funnel clouds extend from thunderstorm clouds, usually near their rotating updrafts.
Cold-air funnel : A usually weak funnel cloud formed in a cold air mass, often beneath a shower or cumulus cloud. These funnels can occur outside the severe, rotating thunderstorms commonly associated with funnel clouds.
Tornado warning : An alert issued when a tornado has been sighted or indicated by weather radar. A funnel cloud may prompt urgent assessment, but warnings depend on evidence of tornado threat.
Scud cloud : A ragged, low cloud fragment formed in moist air beneath a larger cloud. Scud can appear to lower from a storm base but lacks the organized rotation of a funnel cloud.
Wall cloud : A localized, lowered cloud base beneath a thunderstorm, often near its updraft. Funnel clouds can descend from wall clouds beneath rotating thunderstorms.
Cumulonimbus : A tall, dense cloud associated with thunderstorms, heavy rain, and sometimes hail. This cloud type supplies the storm structure from which funnel clouds extend.
Waterspout : A rotating column of air over water, often visible as a funnel or spray vortex. A waterspout may be a tornado over water or a fair-weather vortex with a visible funnel.
Weather radar : A remote-sensing system that detects precipitation and estimates its motion and intensity. Doppler radar can reveal storm rotation even when a funnel cloud is hidden or poorly defined.
Virga : Precipitation that evaporates or sublimates before reaching the ground. Its hanging streaks can look funnel-like from a distance, but they are falling precipitation.
Show all 26