On the nature of the triggering mechanism in hurricane formation.

Abstract

Hurricanes are known to develop under an upper anticyclone which promotes warming of the initial cold-core disturbance and is, in turn, intensified by the warming process. It is shown, from theoretical considerations, that if this process continues until the upper anticyclone approaches maximum intensity dynamic instability, in the form of absolute anticyclonic winds, is released in preferred location with respect to the direction of movement of the anticyclone. A model based on the hypothesis that these absolute anticyclonic winds are instrumental in triggering development is proposed and is shown to be supported by available observations.