Tehuantepecer

Tehuantepecer, or Tehuano wind, is a violent mountain-gap wind traveling through Chivela Pass, most common between October and February, with a summer minimum in July. It originates from eastern Mexico and the Bay of Campeche as a post-frontal northerly wind, accelerated southward by cold air damming, which crosses the isthmus and blows through the gap between the Mexican and Guatemalan mountains. The term dates back to at least 1929. This wind can reach gale, storm, and hurricane force. The leading edge of its outflow (or cold front) may form rope cloud over the Gulf of Tehuantepec. These winds can be observed on satellite pictures such as scatterometer wind measurements, they influence waves which then propagate as swell and are sometimes observed 1,600 km (1,000 mi) away (such as in the Galapagos Islands). These strong winds bring cooler sub-surface waters to the surface of the tropical eastern Pacific ocean and may last from a few hours to 6 days.