In scientific terms, a tornado is a violently rotating column of air that is in contact with both the surface of the earth and a cumulonimbus cloud or, in rare cases, the base of a cumulus cloud. They are often referred to as twisters or cyclones. Continue reading to see five fascinating things you may not have known or seen about them.
5. Steam Devils
A steam devil is a small, weak tornado over water that has drawn fog into the vortex, thus rendering it visible. They form over large lakes and oceans during cold air outbreaks while the water is still relatively warm, and can be an important mechanism in vertically transporting moisture. Smaller steam devils and steam whirls can form over geyser basins even in warm weather because of the very high water temperatures.
4. Fire Whirl
A fire whirl, or fire tornado, is a phenomenon in which a fire, under certain conditions, acquires a vertical vorticity and forms a whirl, or a tornado-like vertically oriented rotating column of air. Most of the largest fire whirls are spawned from wildfires. They form when a warm updraft and convergence from the wildfire are present. They are usually 10-50 meters tall, a few meters wide, and last only a few minutes.
Known officially as “dust-tube tornadoes” by the National Weather Service, landspouts form during the growth stage of convective clouds by the ingestion and tightening of boundary layer vorticity by the cumuliform tower’s updraft. Landspouts most often occur in drier areas with high-based storms and considerable low-level instability. They generally are smaller and weaker than supercellular tornadoes, though many persist in excess of 15 minutes and some have produced F3 damage.
A waterspout is essentially an intense columnar vortex that occurs over a body of water, connected to a cumuliform cloud. In the common form, it is a non-supercell tornado over water. While it is often weaker than most of its land counterparts, stronger versions spawned by mesocyclones do occur. Waterspouts do not suck up water; the water seen in the main funnel cloud is actually water droplets formed by condensation.
1. Multiple Vortex Tornado
A multiple-vortex tornado is a tornado that contains several vortices rotating around, inside of, and as part of the main vortex. They are responsible for most cases where narrow arcs of extreme destruction lie right next to weak damage within tornado paths.