Application of the Hirlam System in China — Torrential Rain Forecasting Experiments in Yangtze River Valley

The HIRLAM system was used in China to test its ability in forecasting the summer torrential rain in Yangtze River valley. The experiments of three selected torrential rain cases show 0 ~ 24 h accumulated rainfall forecasts are quite successful, being able to reproduce most of the observed torrential rain areas (daily rainfall≥50 mm) in the Yangtze River valley. The 24 ~ 48 h accumulated rainfall forecasts vary with different cases. Some cases are successful, some are failure. On the whole 24 ~ 48 h rainfall forecasts are worse than 0 ~ 24 h forecasts, especially for the forecast of daily rainfall≥50 mm.