a tropical wave exited the west coast of africa on july 22 and headed toward the leeward islands, where the system nearly developed into a tropical cyclone but was inhibited by vertical wind shear. by july 31, the system was classified as tropical storm erin while just west of the turks and caicos islands. despite effects from wind shear, erin continued to strengthen as it moved northwestward and was upgraded to a hurricane later on july 31. further intensification occurred, and erin reached winds of 85 mph (140 km/h) before making landfall near vero beach, florida, on august 1. the storm emerged over the gulf of mexico after weakening back to a tropical storm, though it quickly re-strengthened into a hurricane. shortly before making landfall near pensacola beach, florida on august 3, erin briefly intensified into a category 2 hurricane. after moving inland, erin slowly weakened as it tracked across the southern united states and midwestern united states. by august 6, erin merged with a frontal system over west virginia.