Wind and wave fields are computed for the Lake Kasumigaura using numerical atmospheric and wave models. The meso-scale atmospheric model WRF is employed for predicting the wind field over the surface, while the temporal and spatial wave fields are computed by the third-generation wave model SWAN using the output of WRF. The computed results are compared with the observed wind and wave data. The compared periods are chosen during the passing of the typhoons 200704 and 200709. WRF reproduces the observed wind speed and direction quite well at two observation points inside the lake except the peak of typhoon wind. Consequently, the predicted significant wave height and period become smaller than the observed data near the wind peak. The wind field forecasting is also performed using the forecasting meteorological data (GFS). The results show the availability of the present model for forecasting the wind fields over the lake.