Rainfall
Clouds are made up of very small water droplets which are suspended in the air. If the air continues to cool, the small droplets will join together to form larger droplets or ice crystals. Eventually the weight of the water droplets may be heavy enough to make them fall as precipitation (rain, snow, hail, ice).
CLOUD TYPES
There are three main ways in which rising air is cooled to form clouds:
1. convectional
When the ground surface is heated up by the sun, the air above it is warmed up. The air rises and as it cools the clouds form and rain follows. The showery weather and thunderstorms of a British summer are this type of rainfall.
2. Frontal
When a mass of warm air meets air at a lower temperature, it rises up and over the colder, heavier air. Once it is made to rise, cloud and rain will follow due to the process shown in the picture.
The place where warm air and cold air meet is called a front. Frontal rainfall is very common in Britain throughout the year and especially in winter.
The place where warm air and cold air meet is called a front. Frontal rainfall is very common in Britain throughout the year and especially in winter.
3. relief
Relief rainfall occurs when moist air forced to rise over mountains. As it rises it cools and the rainmaking process comes into operation.
Relief rainfall is quite common in Britain especially in the West where most of the land is high.
Relief rainfall is quite common in Britain especially in the West where most of the land is high.