Low-Pressure Area

A low-pressure area, the opposite of a high-pressure system, is a region where the atmospheric pressure is lower than in the surrounding area. It is commonly associated with inclement weather such as cloud cover, wind, and possible rain or storms, in contrast to the lighter winds and clearer skies typical of high-pressure zones. Winds circulate around a low counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere, driven by the Coriolis effect, and the stronger the pressure difference between a low and a neighboring high, the stronger the winds around the low tend to be. When a rotating low-pressure air mass develops a substantial inward wind spiral, it is classified as a cyclone, the largest and most organized form a low-pressure system can take.