Study of severe thunderstorms over bangladesh and its surrounding areas during pre-monsoon season of 2013 using WRF-ARW model

Abstract

Bangladesh is located in the northeastern part of the Indian subcontinent and faces the Bay of Bengal in the south and the Meghalaya plateau in the northeast. Almost the entire country is less than 10 m above sea level and on a flat plane. Severe Thunderstorms (henceforth referred to simply as STS) frequently occur in Bangladesh during the pre-monsoon season from March to May, causing deaths and damage to property every year. In Bangladesh, STSs are classified depending on the magnitude of wind speed. The ones producing wind gusts above 42 m s-1 are defined as tornadoes, while those producing wind gusts ranging from 11 to 42 m s-1 are defined as ‘nor’westers’. The term ‘nor’wester’ means that STS come mostly from the northwestern direction. Despite being highly arbitrary, such criteria for classifying STSs have been used in a number of climatological studies addressing STSs in Bangladesh (Yamane et al. 2008).