2013年島根県西部豪雨を対象としたWRFによるダウンスケール実験

抄録

Downscaling can provide meteorological variables of high-resolution or at local scales from those of lower-resolution. This study aims to clarify the effects of dynamic downscaling on heavy rainfall in the western Shimane prefecture in 2013 using WRF (Weather Research and Forecasting) model. Comparison between the innermost domain results using three nested grids and radar-AMeDAS data shows that the calculated moving pattern of rainfall reasonably corresponds to that by radar observation, while single grid and two nested grids fail to reproduce the heavy rainfall. Downscaling with three nested grids explains that high moisture was transported from high-pressure systems over the Pacific Ocean and the Japan Sea, which converged over Shimane Prefecture to cause the heavy rainfall. Discussion on catchment averaged precipitation demonstrates that Yato river of small catchment area is sensitive to the difference in the location of rainband.