A Cape Verde hurricane or Cabo Verde hurricane is an Atlantic hurricane that originates at low-latitude in the tropical Atlantic from a tropical wave that has passed over or near the Cape Verde islands after exiting the coast of West Africa. The average Atlantic hurricane season has about two Cape Verde hurricanes, which are often the largest and most intense storms of the season due to having plenty of warm open ocean over which to develop before encountering land or other factors prompting weakening. A good portion of Cape Verde storms are large, and some, such as hurricanes Allen, Ivan, Dean, and Irma have set various records. Most of the longest-lived tropical cyclones in the Atlantic basin are Cape Verde hurricanes. While many move harmlessly out to sea, some move across the Caribbean Sea and into the Gulf of Mexico, becoming damaging storms for Caribbean nations, Central America, Mexico, Bermuda, the United States, and occasionally even Canada. Research projects since the 1970s have been launched to understand the formation of these storms and their movement through the Main Development Region.