Anti-cyclone

Anti-cyclone

Meteorologists refer to areas of relatively high air pressure as highs or anti-cyclones. They can be described as an inside-out cyclone (tornado).
Many low-level anticyclones are swept generally eastward by the prevailing west-to-east flow of the upper atmosphere, usually traversing some 500 to 1,000 mi (800-1,600 km) per day. Other anticyclones are permanent or seasonal features of particular geographic regions.
The change between the core of the anti-cyclone and its surroundings, combined with the Coriolis Effect, causes air to circulate about the core in a clockwise direction in the Northern Hemisphere and a counterclockwise direction in the Southern Hemisphere. [VH] {WC} {EP}