Performance of Regional Climate Model (WRF 4.3) in Medium Range Rainfall Forecast (MRRF) for Tamil Nadu, India

Abstract

The weather events are highly dynamic and fluctuating for the next few days due to enormous processes carried out by nature and physics and it is even more highly variable in tropics. The Medium Range Weather Forecast is incredibly helpful and trustworthy for agricultural purposes and rainfall is one of the most imminent events determining productivity. The Medium Range Rainfall Forecast (MRRF) given by Weather Research and Forecast model (WRF v 4.3) is verified using forecast verification scores including Ratio of Root Mean Square Error (RMSE) to the standard deviation of the observations (RSR), Nash-Sutcliffe Efficiency (NSE), Percent Bias (PBIAS), Kling-Gupta Efficiency (KGE), and Root Mean Square Error (RMSE). Scores were computed by comparing forecast generated using two microphysics options viz., WRF Single Moment scheme (WSM-3) and Kessler scheme during South West Monsoon (SWM) and North East Monsoon (NEM) of the year 2021 for five different physiographic regions of Tamil Nadu. WSM-3 microphysics scheme outperformed in predicting MRRF for all the five regions and during both the monsoons.