Rain.
It’s water from the sky, but not all rain is created equal.
There are three types of rainfall.
Orographic, frontal, and convectional.
Orographic precipitation, also known as relief precipitation is most commonly found in coastal
regions with a mountain range.
Wind from the sea contains a lot of moisture, and when it reaches a mountain, it cannot
continue and is forced upwards.
As the air mass goes upwards, it cools and eventually condenses into clouds.
Soon after, the cloud can no longer hold any more water and it begins to rain.
Most of the precipitation ends up on the side facing the ocean, called the windward side,
while the other, or leeward side, gets little.
This causes one side to be moist and full of vegetation, while the other is dry.
Next, there is frontal, or cyclonic precipitation.
When a warm moist air mass meets a cold dry one, the warm one rises, and the water vapour
in the warm air condenses as it rises, forming clouds.
Eventually, it will rain.
If it is a warm front, then the warm air will gradually rise causing a mild to moderate
prolonged rainfall.
If it is a cold front, then the warm air will rise quickly, causing unstable weather including
thunderstorms.
Frontal precipitation is extremely common on the British Isles.
The final type of rainfall is convectional precipitation.
On hot days, the sun heats the ground.
The ground then releases some of that heat which warms the air.
That warm air rises and cools to condense its water vapour into a liquid.
This causes rainfall to initiate almost instantly, usually without much warning.
Since convectional precipitation relies on the sun heating the ground, it is far more
common in tropical regions, where the sun hits at a more direct and intense angle.
These three types of rainfall have ultimately shaped our society, providing the hydration
necessary for vegetation to exist.
And until next time, thanks for watching.