weather term
Low-Pressure System
An area where atmospheric pressure is lower than its surroundings, typically associated with clouds, rain and unsettled weather.
Air spirals inward and rises within a low-pressure system, cooling as it climbs and condensing into cloud and precipitation. Low-pressure systems are the engines behind most rain, wind and storms in the mid-latitudes, and can range from a mild, passing weather front to an intense storm or hurricane depending on how deep the pressure drop is.