Evolution of operational extended range forecast system of IMD: Prospects of its applications in different sectors

The evolution of operational extended range forecast (ERF) system of IMD starting from use of empirical models, dynamic models and the Multi-model Ensemble (MME) from 2009 to 2016 till the operational implementation of fully coupled model in 2016 is discussed. The coupled model implemented in IMD is the Climate Forecast System version 2 (CFSv2). The performance of ERF for southwest monsoon, northeast monsoon, cyclogenesis over the Bay of Bengal (BoB) and maximum and minimum temperature during the period from 2009 to 2018 have been discussed along with its prospects of its application in different sectors like, agriculture, hydrology, health, power etc. are also analysed. The performance of extended range forecasts for the southwest monsoon seasons clearly captured the intraseasonal variability of monsoon including delay/early onset of monsoon, active/break spells of monsoon and also withdrawal of monsoon in the real time in providing guidance for various applications. The MME based ERF also provides encouraging results to provide useful guidance upto 2/3 weeks about northeast monsoon and cyclogenesis potential during October to December (OND) over the north Indian Ocean, heat wave, cold wave during summer and winter with statistically significant correlation coefficient (CC) upto two weeks. For applications in agriculture sector meteorological subdivision level forecasts are prepared for two weeks for the purpose of agro advisory. In addition to the regular ERF products for application in agriculture and hydrology, additional products are being prepared like, Standarised Precipitation Index (SPI), land-surface hydrology products like soil moisture and runoff change, transmission windows products for vector borne diseases etc for applications in agriculture, hydrology and health sectors.