The Speed of Recurving Typhoons over the Western North Pacific Ocean

Abstract

Western North Pacific tropical cyclone data were evaluated for the period 1970?79 to determine characteristics of recurving typhoons near and after recurvature. Case studies revealed a good relationship between typhoon movement speed after recurvature and the upper tropospheric winds at and before recurvature observed along the future typhoon track. This relationship was then determined for a sample of 71 recurving typhoons from 1962 through 1978 and compared with operational forecasts for a subsample of 29 typhoons in 1972?78. The derived simple aid could have reduced the average forecast speed errors by more than 50% in the subsample.