A "firestorm" is a conflagration which attains such intensity that it creates and sustains its own wind system. It is most commonly a natural phenomenon, created during forest fires, and some of the largest forest fires, such as the Great Peshtigo Fire, have been firestorms. A firestorm can also be a deliberate effect of targeted explosives such as occurred as a result of the aerial bombings of Dresden and Tokyo during World War II.
A firestorm is created as a result of the "chimney effect" as the heat of the original fire draws in more and more of the surrounding air. This draft can be quickly increased if a low level jet stream exists over or near the fire, or when an atmospheric temperature inversion cap is pierced by it. As the updraft mushrooms, strong gusty winds develop around the fire, directed inward. This would seem to prevent the firestorm from spreading on the wind, but for the fact that tremendous turbulence is also created by the strong updraft which causes the strong surface inflow winds to change direction erratically. This wind shear is capable of producing vortices akin to dust devils or small tornadoes which can also dart about erratically and q...