On rare occasions, a tropical disturbance can form a little earlier or later than this. Although tropical systems can form anywhere in the Atlantic basin during hurricane season, some areas are more prone to develop tropical storms and hurricanes at certain times of season. By early July, the formation area gradually shifts eastward and continues eastward through late July. The formation area then moves westward in mid-September, returning to the western Caribbean Sea by early October. Hurricanes form in the warm waters of tropical and sub-tropical oceans, seas, or Gulf of Mexico.
Most hurricanes evolve from tropical disturbances.
Also called tropical waves, this is an inverted trough moving generally westward in the tropical easterlies. A trough is defined as a region of relative low pressure. The majority of hurricanes form from easterly waves. WADL's usually move faster than tropical waves. A TUTT is a trough, or cold core low in the upper atmosphere, which produces convection.