MEMPHIS, TN (WMC) - Although tropical systems can technically form any time of year, they are most likely during the Atlantic hurricane season from June 1 to November 30. The peak month for hurricane development is September with 87% of category 1 or 2 hurricanes and 96% of category 3, 4 or 5 hurricanes forming during this month.
Water temperature and wind shear are the factors that contribute to either the strengthening or destruction of a tropical system. During September, there is a large pool of ocean water with temperatures above 79 degrees. Hurricanes typically flourish in waters with temperatures in the lower to mid 80s. As tropical waves move off the coast of Africa they travel west into these warm waters, which stretch north in the Mid-Atlantic states and all the way south into the Gulf of Mexico. This large area of warm water gives these tropical systems plenty of room to flourish into a hurricane.
During September, there is also weaker wind shear in the Atlantic Ocean. This is important because wind shear (increasing wind speed with height) can tear apart hurricanes. This is typically a limiting factor during most of the hurricane season, so even a slight weakening in shear can result in more tropical storms and hurricanes.