American Meteorological Society Certification (AMS) Practice

Anticyclones are effectively known for being areas of high pressure that typically result in dry and stable weather conditions. This occurs because the descending air associated with high-pressure systems inhibits cloud formation and precipitation. As the air sinks, it warms, which further prevents the development of clouds. Therefore, regions under the influence of an anticyclone tend to experience clear skies, light winds, and low humidity levels, contributing to the perception of dry weather.

The other conditions mentioned, such as low pressure with storms, mixed weather patterns, and temperature fluctuations, generally describe other weather phenomena. For example, low-pressure systems are characterized by rising air that often leads to cloud formation and stormy weather. Mixed weather patterns can be attributed to frontal systems or other dynamic atmospheric conditions, while temperature fluctuations can occur in various contexts, not specifically tied to the definition of anticyclones. Thus, the defining characteristic of anticyclones aligns with the association of high pressure and dry weather.