  The paper describes results of numerical experiments on the simulation of a
mesoscale quasi-tropical cyclone, a rare event for the Black Sea, with the MM5
regional atmospheric circulation model. General characteristics of the cyclone
and its evolution and physical formation mechanisms are discussed. The balances
of the momentum components have been estimated, and sensitivity experiments
have been performed. It is shown that, according to its main physical
properties and energy supply mechanisms, the cyclone can be related to
quasi-tropical cyclones.
