Diego Garcia is at minimum risk from tropical cyclones due to its proximity to the equator where the coriolis parameter required to organise circulation of the upper atmosphere is minimal. Low-intensity storms have hit the island, including one in 1901, which blew over 1,500 coconut trees; one on 16 September 1944, which caused the wreck of a Royal Air Force PBY Catalina; one in September 1990 which demolished the tent city then being constructed for United States Air Force bomber crews during Operation Desert Storm; and one on 22 July 2007, when winds exceeded  and over  of rain fell in 24 hours.