Tropical Cyclone Motion and Surrounding Parameter Relationships

Abstract

Ten years of rawinsonde data for 30 stations in the western North Pacific have been composited relative to tropical cyclone center positions. This information is used to study tropical cyclone motion and surrounding parameter relationships. Tropical cyclone motion and lower troposphere surrounding actual and geostrophic flow fields from 1°?7° radius are very well correlated. This general correlation of surrounding flow features applies equally well for cyclones with different directions of motion, speeds of propagation, intensities and intensity changes. The 700 mb level best specifies cyclone speed. The 500 mb level best specifies cyclone direction. The steering flow concept of cyclone motion appears to be quite valid in the statistical sense. These results may be useful to tropical cyclone forecasters.