Cumulonimbus flammagenitus (cloud) on the fujita scale, the first confirmed violent fire tornado. The tornado and associated fire killed 4 people and injured 492. Cumulonimbus flammagenitus (cloud) The cumulonimbus flammagenitus cloud (CbFg) is a type of cumulonimbus cloud that forms above a source of heat, such as a wildfire, and may sometimes even extinguish the fire that formed it. It is the most extreme manifestation of a flammagenitus cloud. According to the American Meteorological Society’s Glossary of Meteorology, a flammagenitus is "a cumulus cloud formed by a rising thermal from a fire, or enhanced by buoyant plume emissions from an industrial combustion process."
Mesoscale convective system of severe weather. The supercell is the strongest of the thunderstorms, most commonly associated with large hail, high winds, and tornado formation. Precipitable water values of greater than favor the development of organized thunderstorm complexes. Those with heavy rainfall normally have precipitable water values greater than . normally greater than , Upstream values of CAPE of greater than 800 J/kg are usually required for the development of organized convection. A mesoscale convective complex (MCC) is a unique kind of mesoscale convective system which is defined by characteristics observed in infrared satellite imagery. Their area of cold cloud tops exceeds with