Operational Extended Range Forecast of Weather and Climate over India and the Applications

Abstract

AbstractMonsoon rainfall over India during June to September shows intra-seasonal variability with spells of above-normal rainfall (active) and subdued rainfall (break) cycles. India Meteorological Department (IMD) with the support from other sister’s organizations of the Ministry of Earth Sciences (MoES) has implemented the operational extended range forecast (ERF) system based on the Climate Forecast System (CFS) version 2 coupled model for extended range forecasts valid up to 3–4 weeks. The operational ERF of rainfall during southwest and northeast monsoon season, maximum and minimum temperature, cyclogenesis potential, etc. has demonstrated useful skill. The ERF for the southwest monsoon season clearly captured the intra-seasonal variability of monsoon including delay/early onset of monsoon, active/break spells of monsoon, and also withdrawal of monsoon at least 2 weeks in advance. The forecast at met-subdivision level is being used for application in Agriculture. Similarly, the cyclogenesis potential in case of Super Cyclone AMPHAN also captured very well 2 weeks in advance, which has the potential application in the disaster management sector. In addition to the regular ERF products for application in agriculture, additional products are being prepared, viz., (i) active phase of monsoon rainfall having potential of heavy rainfall events; (ii) land-surface hydrology products like soil moisture and runoff; (iii) heat wave/cold wave; (iv) transmission window products for vector-borne diseases, etc. for applications in disaster management, hydrology, energy, and health sectors, respectively.KeywordsCoupled modelExtended range forecastIndian monsoonCFSv2Sectoral applications