DEVELOPMENT SIMULATION OF AN UNSEASONAL HEAVY RAINFALL EVENT OVER SOUTHERN THAILAND BYWRFROMS COUPLINGMODEL

A coupled regional climate among atmosphere-ocean coupled model systems is developed using the regional model Weather Research and Forecasting (WRF) and Regional Ocean Modelling System (ROMS). In process of atmospheric, the parameters are used to force the ocean model that included the wind data (Uwind, Vwind), atmospheric pressure data (Patm), relative humidity data (RH), atmosphere surface temperature data (Tair), cloud fraction data (Cloud), precipitation data (Rain), short wave data (SW), long wave data (LW). On the other hand, in process of oceanic, the only parameter of process the oceanic model is used to force the atmosphere model that is Sea Surface Temperature (SST). In this study, to investigate the seasonal prediction and short-term rainfall prediction using WRF and coupled WRFROMS model. The resolution of term rainfall prediction resolution was 36 km× 36 km (domain 1), 12 km × 12 km (domain 2), and 4 km × 4 km (domain 3). The two different microphysics schemes in both cases were Lin scheme and WSM6 scheme. In conclusion, short term rainfall prediction, WRFROMS with WSM6 scheme simulated lower values (RMSE, MAE) and highest value (CORR) than the other experiment. However, the results of the WRFROMS with microphysics improved trend rainfall and SST better than simulation by only WRF model. So, this study found microphysics scheme and SST result from ROMS model that have affected to change results of rainfall prediction. Furthermore, the result of WRFROMS with WSM6 scheme was able to simulate rainfall more accurately when compared with the other experiments by consideration from statistical and quantitative results.