From AMS Glossary
(Also called velocity pressure, stagnation pressure.) In engineering fluid mechanics, the kinetic energy, (1/2)ρV2, of the fluid, where ρ is the density and V the speed.
This applies in cases where this quantity may be conveniently considered as adding to the static pressure; that is, the dynamic pressure at a given point is the difference between the static pressure at that point and the total pressure at the stagnation point of the same streamline. This concept must be distinguished from the hydrodynamic pressure, and the terminology is confusing in meteorological contexts.