Funnel cloud do not become tornadoes. Also, a tornado does not necessarily need to have an associated condensation funnel. If strong cyclonic winds are occurring at the surface (and connected to a cloud base, regardless of condensation), then the feature is a tornado. Some tornadoes may appear only as a debris swirl, with no obvious funnel cloud extending below the rotating cloud base. In cloud nomenclature, any funnel- or inverted-funnel-shaped cloud descending from cumulus or cumulonimbus clouds is technically described as an accessory feature called "tuba". The terms "tuba" and "funnel cloud" are nearly but not exactly synonymous; a wall cloud, for
Cloud seeding Cloud seeding Cloud seeding is a type of weather modification that aims to change the amount or type of precipitation that falls from clouds by dispersing substances into the air that serve as cloud condensation or ice nuclei, which alter the microphysical processes within the cloud. The usual intent is to increase precipitation (rain or snow), but hail and fog suppression are also widely practised in airports where harsh weather conditions are experienced. Cloud seeding also occurs due to ice nucleators in nature, most of which are bacterial in origin. The most common chemicals used for cloud seeding include silver