A comparative study on performance of MM5 and WRF models in simulation of tropical cyclones over Indian seas

Abstract

Tropical cyclone is one of the most devastating and deadly weather phenomenon worldwide. It is a result of organized intense convective activities over warm tropical oceans. In recent years mesoscale models are extensively used for simulation of genesis, intensification and movement of tropical cyclones. In this study, the recent three very severe cyclonic storms generated over Indian seas (Bay of Bengal and Arabian Sea) are considered. During 26-29 April 2006, a very severe tropical cyclone, known as Mala, developed over the Bay of Bengal and crossed the Arakan coast of Myanmar on 29 April 2006. During 2-7 June 2007, a super cyclonic storm, known as Gonu, developed over the Arabian sea and crossed the Makran coast on 7 June 2007. During 11-16 November 2007, a very severe cyclonic storm, known as Sidr, developed over the Bay of Bengal and crossed the Khulna-Barisal coast of Bangladesh on 15 November 2007. In the present study, two state-ofthe- art mesoscale models, MM5 and WRF, developed at the National Center for Atmospheric Research (NCAR), USA, have been used to evaluate the performances of both the models in the simulation of the above-mentioned tropical cyclones. The performances of both the models have been calculated by integrating with 15 different initial conditions, i.e. each case with five different initial conditions. A number of meteorological fields, viz. central pressure, wind and precipitation have been verified against observations/ verification analyses. The vector displacement error in track forecast has also been calculated using the best track provided by the India Meteorological Department. The results indicate that the WRF model has better performance in respect of track and intensity prediction than the MM5 model.