Figure 6: The time series of the equitable threat score (ETS; bars) and bias score (Bias; lines) for 3 hours accumulated precipitation over South Korea during the 12 hours forecast period, for (a) light precipitation (1 mm/3 hours) and (b) heavy precipitaion (10 mm/3 hours) categories. The total number of samples is 976, which consists of 8 times a day for June-July-August 2008. The number of observation used is about 600, which is about 13 km apart over South Korea. The horizontal grid spacing is 5 km covering the Korean peninsula, which is nested by the 15 km grid.