Model prediction of cyclonic tracks over Bay of Bengal and resultant precipitation in the north-east region

Abstract

The Varsha, a spectral hydrostatic general circulation model, is run regularly at an eight-processor Flosolver machine at Gauhati University (26°10′ N, 91°45′ E), with the aims to predicting track of cyclones generated in the Bay of Bengal and forecasting precipitation occurrence and intensity over the north-eastern part (NE) of India, induced by such events. The initial conditions of the model are prepared from FNL dataset of National Centre for Environmental Prediction (NCEP), available at 1°×1° resolutions. The predicted tracks of a few cyclonic events as SIDR (Nov, 2007), Aila (May, 2009) and Laila (May, 2010) are presented along with their contribution to precipitation in the NE. Each prediction, when assessed through observations obtained from satellite-based measurements of Tropical Rainfall Measuring Mission (TRMM) and National Oceanic and Atmospheric Administration (NOAA), and also from India Meteorological Department (IMD), shows that the model-generated zonal wind is a good precursor parameter in track determination of a cyclone. The reliability of the model-projected precipitation features over the NE, contributed by such storms, is also highlighted.