Tornado formation is a relatively simple process. Current theory seems to be based on observation of similar phenomenon occurring in proximate locations. The rolling action of a front does create the tornado’s vertical air movement or spin. The only effect the front has on tornado development is to isolate areas of high atmospheric buoyancy under areas of low atmospheric density. Cold fronts generally flow under warm areas due to their higher density. Some factors, primarily cold front velocity can cause the less buoyant cold front to ‘roll over’ more buoyant stationary air. Front or horizontal weather tornadoes form when more buoyant air vertically ‘escape’ through the front’s cold air confines. Other factors that cause cold front overflow (CFO) include various topology features such as elevation changes and surface flow restrictions.
Another proclaimed cause of tornadoes is the mesocyclone’s spin. A theorem, axiom actually, of this theory is that vertical air movement causes spin. There is no spin without either or both horizontal velocity and vertical velocity. That is not to say that coriolis forces are the only mechanism creating mesocyclone spin, but rather that coriolis forces don’t cause vertical or horizontal air movement; they are a result of horizontal or vertical air movement.
There are two distinct types of tornadoes. A vertical weather tornado’s cause and effect are due to local conditions. A horizontal weather tornado’s cause is horizontal air movement such as a cold weather front. Once a horizontal weather front has created tornado conditions, the self-sustaining tornado process is the same for both vertical weather tornadoes and horizontal weather tornadoes.
Bottom driven tornadoes – Common tornadoes from dust devils to the isolated vertical weather tornado
The dust devil – Simple but revelatory
The isolated vertical weather tornado – Terror of the mid-latitude states
Top driven tornado – What goes up sucks
Thunderhead driver – Sun driven destruction
Inflow squeezing – Concentration of forces
Combination tornado – These are the true monsters of the tornado family.
Fortunately – sort of
Stagnation level – The blanket concentrating tornado ground energy
The Chimney – The release path for tornado ground energy
Rain and hail effects – Rain and hail effects
Anvil (flat top) clouds – Simple but potentially deadly – both in tornadoes and hurricanes.
Visible wall cloud – Is due to moisture
Invisible wall cloud – A wall cloud without moisture