From Glossary of Meteorology


In meteorology, loosely used for any influence upon the direction of movement of an atmospheric disturbance exerted by another aspect of the state of the atmosphere.

Thus, it might be said that a surface pressure system tends to be steered by isotherms, contour lines, streamlines aloft, warm-sector isobars, the orientation of a warm front, etc. Nearly always this principle is applied to the relationship between the velocity of a cyclone and the velocity of the basic flow in which it is embedded.