Abstract: Using results of a numerical simulation,the total and vortex available potential energy is studied.It is found that the potential energy is accumulated before the enhancement of heavy rains and released during the enhancement;the release and enhancement are at their maximum when cold air is off the typhoon,the accumulation and release of energy being active in turn for abont 12 hours;the enhancement of heavy rains is checked with cold air entering the eye,greatly reducing diabatic heating.