A tropical wave, which had formed off from the western African coast on October 15, moved to the Caribbean Seaand reached the Windward Islands on October 19. The wave slowly strengthened and organized into a tropical depression about 180 miles southwest of San Juan, Puerto Rico, on October 22. Later that day, despite wind shear from powerful Hurricane Wilma nearby, it strengthened into a tropical storm as it moved west-northwestward. On the morning of October 23, it made landfall on the Dominican Republic with 50 mph (85 km/h) winds, then moved over to Haiti.