North American High

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The North American High is an impermanent high-pressure cell or anticyclone created by anticyclogenesis (anticyclone + the Greek word genesis, meaning "birth, origin"), a formative process that occurs when cool or cold dry air settles onto western North America. North American Highs moves eastwards across the continent, often in the company of one or more low-pressure cells or cyclones.

The North American High is akin to the Siberian High of Eurasia, but it is much smaller, and it has much less world-wide influence on the weather of the Northern Hemisphere. The sea-level pressure (atmospheric pressure) rarely, if ever, exceeds 1055.0 millibars (1055.0 hectopascals)(hPa)(SI).

Often, in the winter months, cool or cold dry air settles onto the land in the vicinity of the Great Basin where it builds into a high-pressure cell or anticyclone that moves across the United States with its leading edge being called a cold front. After reaching the Atlantic Ocean, the moist environment brings on changes of the qualities of the air and the dissipation of the high-pressure cell or anticyclone as the cold air warms and becomes humid. The slow decay and disappearance of an anticyclone is called anticyclolysis (anticyclone + the Greek word lyein, meaning "to dissolve"; it is used to form many other words, such as paralysis, e.g).