Tornado over West Bengal on 25 May, 2021 in association with Very Severe Cyclonic Storm - YAAS over Bay of Bengal

Abstract

Tropical cyclone (TC) tornadoes are brief and often unpredictable events that can produce fatalities and create economic loss. Climatological studies characterize TC spawned tornadoes as primarily originating from miniature supercells in the outer rainbands. The tornadic features forecasting and radar detection are particularly challenging. In this paper we analyzed the observation data which indicated the occurrence of a tornado over North 24 Parganas and Hooghly districts of West Bengal on 25 May, 2021 in association with Very Severe Cyclonic Storm (VSCS) "YAAS'' which crossed Odisha coast around 0600 UTC of 26^thMay, 2021. The tornado locations were in the convective outer bands of the VSCS "YAAS'' at 0900 UTC of 25^thMay, 2021. The characteristics of the tornado were studied with Kolkata doppler weather radar images, vertical wind profile and sounding data. This tornadoexhibited characteristics similar to typical supercell storms such as hook echo and mesocyclone. This study brings out the conditions favourable for the occurrence of a TC tornado over North 24 Parganas and Hooghly districts of West Bengal in association with VSCS "YAAS''.