On July 29, a low pressure system formed in the southeast Atlantic and slowly drifted westward. The low became associated with a large area of showers and thunderstorms, but the system remained disorganized. A tropical wave accompanied the low as it drifted westward, but the wave disengaged from the circulation, and convection decreased. However, another tropical wave, moving off of Africa combined with the low during the day of July 31, and the systems had totally merged by August 1. However, this time convection persisted within the system and it organized. A flare up of convection that defined the system's center marked the formation of a closed circulation and the system was declared Tropical Depression Four on August 2. Tropical Depression Four's initial movement was swift, to west at 17 mph, due to the steering force of a subtropical ridge to its north. Overnight, Four became more organized, and it was upgraded to Tropical Storm Colin, with 40 mph winds and a pressure of 1006 mb, during the morning of August 3.
Colin accelerated to the west at an even greater speed, reaching a velocity of nearly 25 mph during the day on August 3. Then, the low pressure associated with the system became open, and it degenerated into a remnant low. However, cloud cover persisted within the system, and a new surface low pressure center became evident late on August 4. The system continued to organize, and was redesignated Tropical Storm Colin on August 5. Colin moved northwest and slowed in movement as it encountered a high pressure system, and began to turn east, as with most cyclones in the region. It briefly attained an intensity of 60 mph winds and a pressure of 1005 mb before the circulation became widely separated from the cloud cover again and Colin weakened to a weak tropical storm (45 mph winds) by August 6. Colin became nearly stationary on August 7, and weakened further, barely a tropical storm by the time it resumed movement to the northnortheast later that day. As Colin approached Bermuda, it weakened into a tropical depression, and brought needed rain to the island. Soon after passing west of Bermuda on August 8, Colin lost its circulation and dissipated.
Tropical Storm Colin shortly after reforming on August 5. The circulation, although more organized than before, is clearly exposed.
Track of Colin.
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