Identifying the hotspot regions of emerging triple risk due to pre-monsoon convective storms over Kerala, India

Convective storms CS frequently occur in Kerala during the premonsoon period, particularly in the month of May, presenting numerous hazards such as intense rainfall, lightning, and wind gusts, which cause significant damage to life, property, infrastructure, livelihoods, and various societal sectors. The current study explored the triple-threat nature of convective storms in the month of May over Kerala. This study revealed that CS is accompanied by excessive rainfall in northern regions and exhibits greater intensity than in southern areas. The coastal areas are emerging as the most vulnerable to extreme rainfall hotspots, exhibiting increased intensity from Ernakulam to Kasargod. The topographical characteristics of these regions, encompassing the Kottayam–Idukki border and the eastern sections of Malapuram, also influence rainfall intensity. The districts of Kottayam, Ernakulam, Idukki, and Pathanamthitta are particularly vulnerable to lightning strikes. Over Kerala, CS clouds with brightness temperatures below 240 K and gust winds above 30 kt are particularly hazardous since they pose the triple threat of heavy rainfall, lightning, and strong winds. The study revealed that CS occurs more frequently in regions adjacent to western Ghats WG with northern Kerala exhibiting the highest intensity and southern Kerala displaying a greater frequency of CS.