There seems to exist, "Entropic Balance" in nonlinear flow of super high Reynolds number and moderately high Rossby number, because of significant difference of the time scales between cloud-physical phage changes and supercell. The balance is analogous to the hydrostatic balance, geostrophic balance, cyclostrophic balance and anelastic balance.

　Based on the entropic balance theory, it is attempted to find answer to the questions
　 Is tornadogenesis deterministic or probabilistic ?
　What is the origin of rotation of supercell and tornado ?

　Probabilistic choice of cloud-physical phase changes leads to probabilistic determination of tornadic and non-tornadic supercells. Also, there exists a probabilistic variety of trajectories of air and precipitation particles possible around entropic source and sinks of supercell.

　The entropic balance theory seems to provide a theoretical explanation of mechanism for the tornadic supercell circulations as proposed by Browning (1964) and several other major recent ones. Furthermore, the theory seems to explain better for the mechanisms of both tornadic and non-tornadic supercell, mesocyclone, wall cloud, hook echo, and most importantly tornadogenesis.