Dropwindsonde observations of the environmental flow of Hurricane Josephine (1984): relationships to vortex motion

Abstract

Examination of Josephine's environment revealed a strong variability of the flow with distance from the storm center and with pressure. Josephine moved at right angles to the azimuthally averaged wind at 500 mb; the vortex motion was more consistent with the flow near 700 mb. Forecasts made with a barotropic forecast model showed a high sensitivity of the forecast track to the vertical layer used in the initial analysis. These results demonstrate the potential value of vertical sounding information from the ODWs, and show that single-level midtropospheric information is not always representative of a hurricane's environment flow. On each of the three days, the motion of Josephine deviated significantly from its environmental "steering', as measured by an azimuthal average of the 300-850 mb mean flow over the 5°-7° radial band. -from Author