Formation: In areas intensively heated, hot/warm air rises accompanied by rise in relative humidity. Rising air becomes saturated and water vapour condenses with cloud formed quickly and heavy rains accompanied by thunder and lightening.
Characteristics: Short lived, heavy winds, lightening and thunder. Rain galls within limited areas usually in the afternoons. Clear skies immediately after the rain and hailstone may occur.
Formation: Moist air is forced to rise above a mountain/relief barrier usually on the windward slopes of mountains. Rising air expands and becomes cooler and relative humidity rises and air becomes saturated. Water vapour condenses, cloud is formed with rainfall on the windward slope and descending air on the leeward side
Characteristics: Associated with mountainous regions with even distribution of rainfall over a highland. Windward area has rainfall while leeward side has little or no rainfall and associated with ascending and descending wind.
(iii) Cyclonic Rainfall-Formation: Caused by the meeting of two air masses, the two air masses are different in terms of origin and characteristics. Warm, light, moisture Iadden air rises above cold and dense air. Ascent of the warm air over cold air lowers the temperature of the warm air, cooling takes places and condensation occurs, cloud formation and precipitation follow:
Characteristics: Associated with fronts and weather system in mild latitudes. Rainfall is convectional types in cold front and it lasts for greater duration than convectional rainfall. It covers extensive area and moves from the West to the East in the northern hemispheres and vice-versa in the south