A thunderstorm is a local storm produced by a cumulonimbus cloud.
It is always accompanied by lightning and thunder other characteristics are strong gusty winds, heavy rain, sometimes hail occur.
Three conditions are necessary for the formation of a thunderstorm:
Sufficient water vapor
Unstable lapse rate
Upward lifting, it can be caused by heating from the below, frontal lifting, or by mechanical lifting for example wind blowing upslope on a mountain.
The three stages of a thunderstorm are as follow.
The cumulus stage, it is charactirized by continious updrafts.
The mature stage is characterized by updrafts and downdrafts inside the cloud.
Precipitation inside of the cloud helps to develop the downdrafts.
The start of rain from the base of the cloud signals the beginning of the mature stage.
Thunderstorms reach the greatest intensity during the mature stage.
The dissipating stage, it is chacterized by downdrafts.
