Aerodynamic Models for Hurricanes IV. On the hurricane genesis and   maturing
  This, fourth paper of the series (see previous papers in Refs.[1-3]) derives approximate equations for future numerical studies of initial evolution of hurricanes, develops new analytical models of hurricane genesis and maturing, and presents simple results, which seems to be in accord with observations. Several remarks on tornados are also made at the end of the paper. 
Arkady I. Leonov