The chapter describes the physical and dynamical characteristics of severe storms in the perspective of Bangladesh. An event on 30 March 2018 has been selected as an extreme event that had occurred in the north-eastern part of Bangladesh which damaged crop and houses, and at least six people were killed in different regions of Bangladesh due to severe hailstorms. The high-quality data from European Centre for Medium Range Weather Forecasts (ECMWF) Reanalysis (ERA5) sites were used. The satellite imagery from INSAT of 30 March 2018 were also used. The analysis has shown that lowering of the pressure occurs over Bangladesh and adjacent areas of India within the pre-existing east–west oriented low-pressure trough. The strong warm south-westerly low-level winds pump a plentiful amount of moisture from the head Bay of Bengal in to the land areas of Bangladesh. The cool and dry airmass enters the area from the northern mountain and forms a discontinuity with dryline interface. The surface temperature distribution shows the thermal discontinuity and vector winds indicate the airmass discontinuity. These conditions initiate the convective activities to the north of Bangladesh as early as 0000 UTC, which is clearly seen in the satellite imagery. The area of occurrence of the severe storms are characterized by the high value of low-level relative vorticity in the order of > 150 × 10–5 s−1, high value of low level convergence in the order of > 40 × 10−5 s−1, high value of vertical velocity of wind higher than 12 m/s, high value of CAPE higher than 3000 J/kg and low value of CINE (<50 J/kg), high value of cloud-water mixing ratio in the order of > 30 g/kg and very high value of ice-water mixing ratio higher than 80 g/kg and low-level reflectivity > 50 dBZ with vertical extents upto 150 hPa level with a core at 500 hPa level. The above physical and dynamical characteristics of severe storms are found for the thunderstorm case and may be considered as the prerequisites for genesis of the severe storms over Bangladesh.