Dry-line, nor’westers and tornadic storms over east India and Bangladesh : An operational perspective through synergie, the new IMD forecaster’s workstation

Abstract

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 Pre-monsoon is a very challenging period for regional duty-forecasters and those involved in mitigation of severe weather consequences. Indeed, violent thunderstorms producing high winds, large hail and even tornados are common features from March to May in East India and Bangladesh. Taking advantage of SAARC (South Asian Association for Regional Cooperation) research publications, as well as knowledge and practical methodology developed by NOAA’s National Weather Service in the Tornado Alley, a methodology is proposed that might help IMD forecasters make the best use of their new workstation SYNERGIE. The case study of the 13 April 2010 severe storm has been chosen for this purpose. More than 140 reported deaths and nearly 500,000 people were left homeless or otherwise affected by the storm. A good comprehension of both synoptic and mesoscale conceptual models is needed; then, aided by appropriate numerical model fields, drawing proper weather symbols on surface analysis charts is an important step towards the building and sharing of local expertise with regional or local forecasters. A graphical analysis is proposed and discussed.