Such factors include, the level of the water table, geological formations including soil and rock deposits over a period of time, or the general stability of the soil and rock in the area. An epicenter is the point on the earth's surface directly above the point inside the earth's mantle that is the focus or the source of the earthquake. Any short-lived, violent atmospheric disturbance characterized by thunder, lightning, gusty surface winds, hail, precipitation,etc constitutes a thunderstorm. It is an event of relatively short duration. Water drops from a thunderstorm are small, and they evaporate before reaching the ground as precipitation.
Thunderstorms are most likely to occur in a moist, unstable atmosphere.
Air masses having these properties are commonly formed over equatorial and tropical areas. Disturbances in the wind field caused by pressure changes in topography lead to an upward displacement of the air initiating the development of thunderstorms. The lightning, which is present in all thunderstorms, is an electrical discharge that balances the difference between positive and negative charges within a cloud, between two clouds, or between a cloud and the ground. Thunderstorms have been known to occur in almost every part of the world. They are, however, rare in the polar regions.