Understanding the Properties of Cyclonic Storm ‘Aila’ Using NWP Technique - Monitoring and Prediction of Tropical Cyclones in the Indian Ocean and Climate Change - page 367

Understanding the Properties
of Cyclonic Storm 'Aila'
Using NWP Technique
Md. Abdul Mannan* and Arjumand Habib
SAARC Meteorological Research Centre (SMRC)
E-4/C, Agargaon, Dhaka, Bangladesh
*e-mail: [e-mail]
1. Introduction
The Bay of Bengal is a potentially energetic region for the development of
cyclonic storms and accounts for about 7% of the global annual total number
of tropical storms (Gray, 1968). These storms, in particular the post-monsoon
storms, are highly devastating causing loss of life and damage to property,
especially when they cross the coastal states of India and Bangladesh (De
Angelis, 1976). Therefore, reasonably accurate prediction of the Bay of Bengal
cyclones is of great importance to avoid or reduce the loss of life and damages
to property. With increasing computer resources, in the last half decade, many
of the NWP centres started using higher resolution models for tropical cyclone
prediction to reduce errors associated with finite differencing (Dudhia, 1993)
and for better representation of topographical features and sub-grid scale
physical processes (Mandal et al . , 2003).
In the present study, Weather Research and Forecasting (WRF) model
(version 3.2.1) is used to simulate cyclonic storm 'Aila' formed in the Bay of
Bengal and crossed West Bengal coast near Sagar Island between 0800 and
0900 UTC of 25 May 2009.
2. Model Description
In this study, WRF model is used at 09 km horizontal resolution with 27 vertical
sigma levels. The model is integrated using six hourly LBCs from NCEP/FNL
analysis. Kain-Fritsch (hereafter referred as KF) cumulus parameterization
scheme with the combination of Ferrier (referred as FR), Kessler (referred as
KS), Lin et al. (referred LN), WRF Single-Moment 3 Class (referred WSM3)