Typical conditions for tropical cyclones generation have been analyzed. The complex criterion W is proposed to characterize a probability of cyclone generation and its power. The criterion can be calculated based on three parameters: the ocean surface temperature, the above-surface relative humidity of air, and the geographic latitude. The estimates of probabilities of the tropical cyclones generation based on the criterion suggested and on the frequency of cyclone generation during the 16-year period have been compared. Besides, the average values of the total energy and kinetic energy of a cyclone were calculated using the method developed and compared to available estimates. A good agreement of these estimates proves the usefulness of the criterion suggested and indicates a need of the further investigation of physical phenomena, which enabled us to formulate the criterion.