Operation decision using the latest weather forecasting technology -IV -Risk assessment of strong winds for berthing and unberthing -

Abstract

In this study, we investigated the risk of large vessels encountering strong winds during berthing and unberthing using wind direction and speed data from The Automated Meteorological Data Acquisition System (AMeDAS) observations by the Japan Meteorological Agency and grid point values from the Meso-Scale Numerical Weather Prediction Model (MSM-GPV, approximately 5km resolution). An investigation of the maximum instantaneous wind speed values at AMeDAS observation points in Kobe, Kobe Airport, and Kansai International Airport in Osaka Bay revealed that the risk of encountering strong winds varies significantly with the wind direction and speed from MSM grid point values. When the wind speed at the MSM grid points near the observation points is 7-10 m/s, the risk of encountering strong winds is higher at observation points close to the land compared to those offshore. For example, at the Kobe AMeDAS observation point, the probability of the maximum instantaneous wind speed exceeding 15 m/s reaches 58% with an ENE wind direction. At the AMeDAS observation points in Kobe Airport and Kansai International Airport, the risk of encountering strong winds is high with the SSW wind direction, therefore there is the need to take caution with the winds from the SSW.