Radius and Frequency of 15 m s−1 (30 kt) Winds around Tropical Cyclones

Abstract

Over 8500 rawinsonde soundings within 8° radius of tropical cyclones in the northwest Pacific and West Indies regions are statistically analyzed to determine occurrence frequencies of 15 m s?1 (30 kt) winds at the sea surface. At any radius the likelihood of encountering winds >15 m s?1 is found to increase with increasing central wind speed and with increasing radius of the highest closed isobar. There are significant right-side wind maxima and left-side minima with respect to the direction of storm motion. This reflects the natural storm asymmetry. Much variability is found in the radius of 15 m s?1 winds between cyclones of similar inner core intensity.