Abstract 216

Abstract ID: 216

Assessing skill of ensemble sub-seasonal to seasonal forecasting over South-east Asia

Lead Author: Paromita Chakraborty
National Centre for Medium Range Weather Forecasting (NCMRWF), India

Keywords: sub-seasonal to seasonal, coupled ensemble, hindcasts, probabilistic skill, monsoon onset

Abstract: Sub-seasonal to seasonal predictions using comprehensive coupled dynamical models have been shown to exhibit useful skill over South-east Asia which is crucial in the development of adaptation strategies to climate change. The fully global coupled sub-seasonal to seasonal ensemble system at based on UK Met Office GloSea5 seasonal forecast system is used for extended-range prediction at National Centre for Medium Range Weather Forecasting (NCMRWF). The lagged initial conditions are used to generate the ensemble members. Physics perturbations are obtained from Stochastic Kinetic Energy Backscatter scheme. The precipitation anomalies are computed based on the hindcasts during the boreal summer season. The skill of the model in predicting monsoon onset is studied based on the westerly shear indices. The probabilistic skill of multi-week forecasts is verified with reference to ERA-interim reanalysis which helps assess the forecast uncertainty well ahead in time, enabling risk assessment and effective planning for disaster management.

Co-authors:
D. K. Mahapatra, National Centre for Medium Range Weather Forecasting
Imran Ali, National Centre for Medium Range Weather Forecasting
V. S. Prasad, National Centre for Medium Range Weather Forecasting