On August 18, 2008, a tropical wave which had left the coast of Africa five days previously, developed into a significant low pressure area about 600 miles (970 km) west-southwest of the Cape Verde islands.
This wave moved westward across the Atlantic in conditions that were not favorable for development.
As it began to approach the Windward Islands conditions improved and it showed some signs of organization, but no circulation.
Upon reaching the windward islands on August 23, bringing showers, thunderstorms, and generally squally weather, wind shear over the system decreased and atmospheric conditions improved.
Over the eastern Caribbean Sea, about 250 miles (400 km) south of Santo Domingo, a low level circulation began to form.
Hours later well-defined curved bands and an improving circulation at the surface warranted that the system be designated a tropical depression.

The depression formed a small inner wind core 12 mi (19 km) in diameter which allowed it to rapidly organize, and on the afternoon of August 25 it was upgraded to a tropical storm and first given the name Gustav.
A renewed period of disorganization proved to be very short lived, and that night a well-defined eye formed.
This eye was accompanied by strengthening as the storm continued to move northwest towards Haiti.
Before reaching the island, Gustav's strengthening pattern raised it to hurricane strength.
Its prominent and organizing central dense overcast belied persistent strengthening which continued until Hurricane Gustav made landfall on Haiti's southwest peninsula about 10 mi (16 km) west of Jacmel, at around 1800 UTC on August 26, with winds of 80 mph (130 km/h) and a minimum central pressure of 992 mbar (29.29 inHg).
On August 18, 2008, a tropical wave which had left the coast of Africa five days previously, developed into a significant low pressure area about 600 miles (970 km) west-southwest of the Cape Verde islands. This wave moved westward across the Atlantic in conditions that were not favorable for development. As it began to approach the Windward Islands conditions improved and it showed some signs of organization, but no circulation. Upon reaching the windward islands on August 23, bringing showers, thunderstorms, and generally squally weather, wind shear over the system decreased and atmospheric conditions improved. Over the eastern Caribbean Sea, about 250 miles (400 km) south of Santo Domingo, a low level circulation began to form. Hours later well-defined curved bands and an improving circulation at the surface warranted that the system be designated a tropical depression.
The depression formed a small inner wind core 12 mi (19 km) in diameter which allowed it to rapidly organize, and on the afternoon of August 25 it was upgraded to a tropical storm and first given the name Gustav. A renewed period of disorganization proved to be very short lived, and that night a well-defined eye formed. This eye was accompanied by strengthening as the storm continued to move northwest towards Haiti. Before reaching the island, Gustav's strengthening pattern raised it to hurricane strength. Its prominent and organizing central dense overcast belied persistent strengthening which continued until Hurricane Gustav made landfall on Haiti's southwest peninsula about 10 mi (16 km) west of Jacmel, at around 1800 UTC on August 26, with winds of 80 mph (130 km/h) and a minimum central pressure of 992 mbar (29.29 inHg).
Meteorological history of Hurricane Gustav