# Wind pressure

From Glossary of Meteorology

## wind pressure

(

*Also called*velocity pressure.) The total force exerted upon a structure by wind.For a flat surface it consists of two factors, the first being the dynamic pressure exerted on the windward side of the surface (wind load). This is equal to (1/2)ρ This formula should be used with caution. The actual wind pressure depends on the shape of the object and the nature of the environment. For objects not presenting a flat surface to the wind, such as bridges and chimneys, complicating aerodynamic factors are introduced that make the above formula invalid.

*v*^{2}, where ρ is the air density and*v*is the wind speed normal to the surface. The second factor is the pressure decrease, or suction, produced on the leeward side of the surface, which is equal to (1/2)*c*ρ*v*^{2}, where*c*is a structural constant varying from -0.3 for cylindrical objects to 1.0 for long plates. The wind pressure*p*is the sum of these two, or