A mesoscale convective complex, or large circular area of thunderstorms, developed in the Ethiopian Highlands of Africa on July 28. The complex moved west-southwestward through the continent, waxing and waning until persisting along a tropical wave on August 2. The next day, the wave emerged into the Atlantic Ocean from Guinea. Once over the open Atlantic Ocean, the wave quickly developed and became Tropical Depression Three later that day. The depression moved to the west-northwest and was upgraded to Tropical Storm Alberto early on August 4. Alberto continued to strengthen, but moved to cooler waters late on August 5 and weakened briefly. However, the storm strengthened again early on August 6, and it was upgraded to hurricane status as an eye became visible. The upgrade was accompanied with a brief westward turn. However, Alberto continued to move to the west-northwest later that day, reaching its first peak intensity of 90 mph (150 km/h) on August 7.