Effect of global warming on thunderstorm frequency in Bangladesh

Climate change is projected to have a significant influence on the frequency, intensity, duration, and timing of climate extremes. Bangladesh is already known as one of the most vulnerable countries in the context of climate change due to its disadvantageous geographical location. In recent years, extreme weather events like thunderstorms and lightning activity have become more frequent in Bangladesh, resulting in increased lightning fatalities and injuries. This study examines how the frequency and regional variability of future thunderstorm activity in Bangladesh might change due to global warming in the twenty-first century, based on global climate model data under the RCP 8.5 scenario from the Coupled Model Intercomparison Project-Phase 5. Initially, we studied the climatology of convective available potential energy (CAPE), which has been widely used to characterize the meteorological conditions that foster severe thunderstorm formation. Later, using precipitation and CAPE, different statistical thunderstorm (TH) frequency prediction models were developed. The results show that the risk of thunderstorms in Bangladesh is expected to increase in a warmer future climate, likely due to the projected rise in CAPE. Country-average CAPE could increase by up to 45% during the pre-monsoon, which is the most thunderstorm-prone season in Bangladesh. Annual changes in TH frequency at different stations across Bangladesh are projected to vary between −3% to 20% in the 2020s, 9% to 35% in the 2050s, and 16% to 60% in the 2080s. The country-average changes in TH frequency for the pre-monsoon, monsoon, post-monsoon, and winter seasons in 2080 are projected to be 39, 35, 68, and 41%, respectively.