Cyclostrophic wind

From Glossary of Meteorology

cyclostrophic wind

That horizontal wind velocity for which the centripetal acceleration exactly balances the horizontal pressure force:
where Vc is the cyclostrophic wind speed, R the radius of curvature of the path, α the specific volume, p the pressure, and n the direction normal to the streamlines toward the center of curvature of the path.

The cyclostrophic wind can be an approximation to the real wind in the atmosphere only near the equator, where the Coriolis acceleration is small; or in cases of very great wind speed and curvature of the path (such as a tornado or hurricane), so that the centripetal acceleration is the dominant one.
See Eulerian wind.