Anthropogenic cloud
The intermediate layers of the troposphere are the regions with less influence of human activity. This region is far enough from the surface for not being affected by the surface emissions. Additionally, commercial and military flights only cross this region during ascending or descending maneuvers. Moreover, in this region there exist two types of clouds with a large horizontal extension: "Nimbostratus" and "Altostratus", which cannot originate from human activity. Consequently, it is assumed that there are no anthropic clouds of these two "genera". However, what can occur is enhancing existing "Nimbostratus" or "Altostratus" due to the additional water vapor or condensation nuclei emitted by a thermal power plant, for instance.
Tornado
Various types of tornadoes include the multiple vortex tornado, landspout and waterspout. Waterspouts are characterized by a spiraling funnel-shaped wind current, connecting to a large cumulus or cumulonimbus cloud. They are generally classified as non-supercellular tornadoes that develop over bodies of water, but there is disagreement over whether to classify them as true tornadoes. These spiraling columns of air frequently develop in tropical areas close to the equator, and are less common at high latitudes. Other tornado-like phenomena that exist in nature include the gustnado, dust devil, fire whirl, and steam devil.