The Beaufort scale indicates the strength of the wind.
Wind is the movement of air through the atmosphere.
It is caused by atmospheric pressure = pressure of the air in the atmosphere.
Air going down = high pressure (H)
Air rising up = low pressure (L)
Law of Buys Ballot = The flow of the wind is always from high pressure areas to low pressure areas. Furthermore, this wind is deflected towards the right in the Northern Hemisphere and to the left in the Southern Hemisphere.