positive vorticity

positive vorticity

Vorticity caused by cyclonic turning. Vorticity is a measure of rotation in the atmosphere, or “spin,” in the air. If the spin, as viewed from above, is counterclock-wise in the Northern Hemisphere, it is called vorticity cyclonic and given a positive value (i.e., it is called positive vorticity). Positive vorticity is associated with the upward motion of air.