TROPICAL CYCLONE RECURVATURE AND NONRECURVATURE AS RELATED TO SURROUNDING WIND-HEIGHT FIELDS.

Abstract

Ten years of rawinsonde data for 30 stations in the western North Pacific have been composited relative to tropical cyclone center positions. These data were used to study prior (12-72 h) differences in surrounding environmental fields between tropical cyclones which recurved and those which did not. Differences in the wind, height and temperature fields out to 21 degree radius to the north between these two classes of storms are presented. A strong recurvature correlation is found in the 200 mb wind and height fields at large radii to the north. It is suggested that an operational long-range (2-3 days) tropical cyclone recurvature forecast scheme can be developed using upper tropospheric wind-height data.