How do you define convectional rainfall?

Answer 1

Convectional rainfall occurs when the energy of the sun (or insolation) heats the earth's surface and causes water to evaporate changing to water vapor. This warm, moist air then rises and as it rises it cools. The air reaches a point called the condensation level where it has cooled to such an extent that the water vapor condenses and turns back to a liquid form. This process of condensation high in the atmosphere leads to the development of clouds. As the clouds continue to grow the weight of the water droplets can eventually lead to precipitation

Answer 2

This is more likely to occur in hot or semi tropical countries. The sun heats the earth and warm air rises. As it rises, it cools, and water vapour condenses to form clouds. Cumulus clouds are formed which are unable to support the the accumulated water and thus heavy rain storms occur, including thunder and lightening.