Central_American_gyre
Central American gyre
Broad rainy season low-pressure system
The Central American gyre (CAG) is a broad and seasonal area of low pressure that occurs over the eastern Pacific Ocean and western Caribbean Sea. It primarily develops annually during the region's rainy season between May and November, and most commonly occurs during late spring (May–June) and early fall (October–November).[1][2]: 1999 CAGs are a type of monsoonal low and share similarities with monsoonal lows in other oceanic basins.[2]: 1983 The broad counterclockwise circulation of winds associated with CAGs is weak.[3][4] CAGs may span across hundreds of miles,[3] potentially covering parts of the eastern Pacific Ocean, southern Gulf of Mexico, and western Caribbean Sea.[5]
CAGs are also slow-moving and can last on the order of days to weeks as they move over Central America and persistently generate inclement weather.[3][4][6] Consequently, with the aid of the nearby ocean waters,[7] CAGs can produce prolific amounts of rainfall over Central America, presenting a risk for flash floods and mudslides.[1][8] The terrain of Central America may influence the development and organization of the showers and thunderstorms associated with CAGs.[2]: 1999 On average, precipitation associated with CAGs most commonly occurs along the coast of Central America.[2]: 1983 Tropical cyclones over the western Caribbean Sea and southern Gulf of Mexico may draw moisture from a nearby CAG, enhancing the amount of rainfall they produce.[9] The presence of a CAG may also push rainfall associated with tropical cyclones in the southern Gulf of Mexico towards the south and west.[10]