Numerical Analysis of Failed Forecasts of Waves Under Low Pressures From Viewpoint of Ship Operation

Today, weather routing becomes more important under the current situation of international maritime transportation. However, the authors reveal that the current systems are not necessarily sufficiently reliable. It is also worthwhile to consider the background of the difficulty in numerically forecasting winds and waves. Here, two failed cases of wave forecasts are verified using WRF and SWAN, two numerical meso-meteorology models. In both failed cases, low pressures developed from the southern sea area of Japan with a northeast direction. First, wind direction can be reproduced correctly, even if the resolution of the simulation is changed. Second, if the resolution is insufficient, wind speed will be underestimated as smaller than the observed values. At the same time, wave height tends to be underestimated as compared to observed values, too. This is the feasibility study for improving the forecasting of wave growth pattern due to developing low pressures from the viewpoint of safe ship operation.