High crosswinds associated with tropical cyclones (TC) are known to be one prime weather factor causing significant flight delay and flight cancellation at the Hong Kong International Airport (HKIA). An empirical model based on the TC parameters including the TC wind radii, forecast positions and intensities was developed to provide objective guidance on wind forecast at HKIA during the passage of TCs. Adjustments to the forecast were made to account for the surface property (land/sea/coastal area) that the TC moves across and the local terrain effect.

A web-based interactive tool was implemented for displaying model wind forecasts at hourly intervals up to 36 hours ahead. The model outputs are generated automatically based on the TC parameters in the HKO’s TC warning bulletins and are updated every three hours. Manual adjustment to the TC parameters can be applied on-the-fly to enable generation of model output to facilitate forecaster’s formulation of alternative scenario of wind forecast and hence strengthening the forecast strategy taking into account the forecast uncertainty of individual TC parameters.

This paper presents the formulation of the empirical model and the evaluation of the performance of model wind forecasts for HKIA using historical TC cases.