Hurricane Irma dropped extremely heavy rain at times during it’s trek from near the Cape Verdi Islands through the northern Leeward islands, Cuba and the southeastern United States. Over 16 inches (406 mm) of rain was reported in Guantanamo, in the easternmost province of Cuba, as the category five hurricane battered the country. Almost 16 inches (406 mm) of rain was also reported at Fort Pierce on the eastern side of Florida. Charleston, South Carolina reported 6 inches (152.4 mm) of rain in 24 hour.
The National Hurricane Center (NHC) upgraded a low pressure area in the far eastern Atlantic Ocean to tropical storm Irma on August 30, 2017 at 11:00 AM AST (1500 UTC). Tropical cyclones that form in that part of the Atlantic Ocean are often the largest and most powerful hurricanes of the season. Hurricanes Ivan (2004), Isabel (2003), Hugo (1989) and Allen (1980) are examples of past powerful hurricanes that formed near the Cape Verde islands.