LAUSR

The present study focuses on evaluating the ability of short-range rainfall forecasts from the Weather Research and Forecasting (WRF) model against observed gridded rainfall data from the India Meteorological Department (IMD) available over the Indian landmass during Indian summer monsoon (ISM) viz. June to September for the year 2014. The spatial distribution of the WRF predicted rainfall matches well with the IMD observed rainfall and indicates systematic rainfall biases over the Indian landmass. In general, precipitation is underestimated in dry, low elevation areas and overestimated in wet, high elevation areas by the WRF model. Based on rainfall verification scores, it was found that low and moderate rainfall was forecasted reasonably well by the WRF model compared to heavy rainfall. Moreover, extremal dependency score (EDS) has been used to verify heavy rainfall forecasts, as the traditional threat scores saturates towards high rainfall thresholds. Further, the separate analysis was carried out over five different homogeneous rainfall zones of India. Results show that the WRF model was able to predict rainfall reasonably well with higher correlation coefficient, lower bias and root mean square deviation in most of the zones. Moreover, the WRF rainfall forecasts at high spatial resolution (5 km) were also examined over Karnataka, India using dense rain gauge network.