The origins of Bonnie were in a tropical wave that emerged from the coast of Africa on July 29 and entered the Atlantic Ocean. It moved westward, attaining convection and a mid-level circulation. Convection steadily increased, and, upon the development of a low-level circulation center, the system organized into Tropical Depression Two on August 3 while 415 miles (670 km) east of Barbados. It moved rapidly westward at speeds of up to 23 mph (37 km/h); after crossing through the Lesser Antilles on August 4, it degenerated back into a tropical wave.
The tropical wave continued to move rapidly to the west-northwest, until it reached the western Caribbean Sea. While south of Cuba and through the Cayman Islands, the system slowed down to regenerate convection, and it re-developed into a tropical depression on August 8. Operationally, the system was classified a tropical wave until a day later. The depression moved through the Yucatán Channel, and intensified into Tropical Storm Bonnie on August 9 while 70 miles (115 km) north of the Yucatán Peninsula.
Bonnie to the north of Charley on August 12
Bonnie continued to the west-northwest; late on August 9, the storm presented a 9-mile (15-km) wide eyewall, a very unusual occurrence in a small and weak tropical storm. Bonnie quickly strengthened while turning to the north, a directional shift caused by a break in the mid-level ridge. The storm briefly weakened late on August 10; it re-strengthened again the following day to attain a peak intensity of 65 mph (100 km/h). Soon after, strong southwesterly wind shear disrupted the storm, causing Bonnie to weaken again. On August 12, Bonnie made landfall just south of Apalachicola as a 45 mph (75 km/h) tropical storm. It quickly weakened to a tropical depression, and accelerated northeastward through the southeastern United States. After paralleling the Georgia, South Carolina, and North Carolina coastlines, Bonnie lost its tropical characteristics on August 14 to the east of New Jersey. Its remnant low continued northeastward, making landfall in Massachusetts and Maine and continuing into Atlantic Canada.