"Andrew started modestly as a tropical wave that emerged from the west coast of Africa on August 14. The wave spawned a tropical depression on August 16 which became Tropical Storm Andrew the next day. Further development was slow, as the west-northwestward moving Andrew encountered an unfavorable upper-level trough. Indeed, the storm almost dissipated on August 20 due to vertical wind shear. By August 21, Andrew was midway between Bermuda and Puerto Rico and turning westward into a more favorable environment. Rapid strengthening occurred, with Andrew reaching hurricane strength (sustained winds greater than 73 mph) on the 22nd and Category Four status on the Saffir-Simpson Hurricane Scale on the 23rd. After briefly weakening over the Bahamas, Andrew reached Category Five status as it crossed south Florida on August 24. "