Hydra Home FAQ The scale of Beaufort Bft and m/s

Wind speed and wind pressure

The wind pressure can be approximated by: Pressure = ½ x (density of air) x (wind speed)² x (shape factor)

• The density of air is about 1.25 kg/m³.
• The shape factor (drag coefficient) depends on the shape of the body. It has order of magnitude 1 and is dimension less.
• The wind speed must be expressed in m/s. In that case the pressure has units kg/m/s², i.e. N/m².

Since the scale of Beaufort and the wind speed are not related linearly, it is not possible to express the wind pressure as:
Pressure = (constant) x (wind speed in Bft)².