ROLE OF DIFFERENTIAL FRICTION AND ASYMMETRY OF THE TOTAL FLOW ON HURRICANE MOVEMENT

Abstract

Under elementary considerations the vorticity changes induced by differential friction and asymmetry of the combined hurricane and large-scale flows were incorporated in the prediction equation and integrated with a view to forecasting the movement of hurricanes. After determining the difference between frictional and frictionless forecasts based upon idealized data, seven 24-hr and four 48-hr frictional and frictionless forecasts of the movement of hurricane Cleo, 1964, were obtained. Introduction of surface friction resulted in improved 24-hr directions of movement and reduced the magnitude of vector error in the 48-hr displacement. Causes underlying the observed improvement were analyzed.