  Based on the Boussinesq equations and the equation of state, a new fluid
dynamical model coupling heat is established. Furthermore, the conditions for
interior separation, which are determined by the initial conditions, are
obtained. This result is derived from the new model by using the interior
separation theorem which was established by T. Ma and S. Wang in
\cite{TM-SW1,TM-SW3}. The most important application of this result is to
predict when and where tornado and hurricane will occur.
