describes rainfall that is produced when convectional currents
form in the atmosphere. When the earth's surface is heated, as on hot summer days, the temperature of the air above it increases. Heated air rises, forming an updraft
. The rising air gradually cools as it ascends through the atmosphere. Water vapor in the cooling air condenses to form clouds, eventually precipitating
to form either rain or hail. Rain cools the surrounding air as it falls. Cooled air descends towards the ground, forming a downdraft
(the strong gusts of wind just before and during a storm are caused by these downdrafts). This forms the initial convectional current. Rain cools the surface of the earth, eventually blocking the formation of further updrafts. This ends the convectional current cycle, and precipitation eventually disappears.