In the sections, pressure areas and coriolis force, we found out that wind wants to go from high pressure areas to low pressure areas and that the coriolis force tries to deflect that path to the right in the Northern Hemisphere and to the left in the Southern Hemisphere.
When wind is coming from a high pressure area, it isn't deflected much by the coriolis force. As it speeds up, it deflects more, until both the pressure gradient force and Coriolis force are in balance. Now wind blows parallel to isobars and can be called a geostrophic wind.

Geostrophic winds are quite rare, because most of the time there are other forces that influence wind, making isobars round. However, at high altitudes wind is almost geostrophic.

Coriolis is the force which develops because of the rotation of the earth. It makes global winds bow. See also: Coriolis effect

Isobars are lines on weather maps which show pressure areas. See also: Isobars

A force created by difference in pressure. This triggers the initial movement of air. See also: Pressure gradient

Coriolis is the force which develops because of the rotation of the earth. It makes global winds bow. See also: Coriolis effect

Isobars are lines on weather maps which show pressure areas. See also: Isobars

A force created by difference in pressure. This triggers the initial movement of air. See also: Pressure gradient