Importance of integration of subseasonal predictions to improve climate services in Sri Lanka case study: Southwest monsoon 2019

The climate outlook for the 2019 southwest monsoon (SWM) season was prepared through an expert assessment of the prevailing global climate conditions and forecasts from different climate models from around the world during the fourteenth session of the South Asian Climate Outlook Forum (SASCOF14). Above-normal rainfall was predicted over Sri Lanka for SWM 2019, and information was shared at the monsoon forum. Even though SWM 2019 seasonal rainfall wasslightly above average, highly uneven rainfall distribution with a deficit of rainfall at the beginning and a surplus of rainfall during the latter part of the season was observed. Unusual dry conditioned prevailed during the month of May 2019, which led to delay the onset of SWM by 2 weeks. Due to the delay of onset and rainfall deficit during the early part of2019 SWM, late cultivation of paddy was observed.Hydro-catchment areas recorded large shortfalls in early part Southwest Monsoon rainfall reducing hydropower generation to 15–18%, from May to July. The suppressed phase of Madden Julian Oscillation (MJO) (phase 6 to 8) with anomalous easterly winds over Sri Lanka was evident from 04th May to 25th May. As MJO being a major predictive source in subseasonal timescale and Sri Lanka being a country located in the heart of the MJO envelope, integration of subseasonal information into seasonal outlook provide much greater value to decision-makers in Agriculture and Energy sector.