Tropical Storm Helene was a long-lived tropical cyclone that oscillated for ten days between a tropical wave and a tropical storm. It was the twelfth tropical cyclone and eighth tropical storm of the 2000 Atlantic hurricane season, forming on September 15 east of the Windward Islands. After degenerating into a tropical wave, the system produced flooding and mudslides in Puerto Rico. It reformed into a tropical depression on September 19 south of Cuba, and crossed the western portion of the island the next day while on the verge of dissipation. However, it intensified into a tropical storm in the Gulf of Mexico, reaching its peak intensity while approaching the northern Gulf Coast. The storm rapidly weakened before moving ashore near Fort Walton Beach, Florida on September 22. It produced heavy rainfall along the Florida Panhandle that reached . The rains flooded hundreds of houses and caused the Sopchoppy River to reach a record crest. Gusty winds left about 5,000 people without power, though the rains alleviated drought conditions. In South Carolina, Helene spawned a tornado that killed one person and injured six others; heavy rainfall in the state also led to a death when a driver hydroplaned into a tree. The rainfall extended northeastward into Delaware. Overall damage in the United States was estimated at $16 million. Helene emerged from North Carolina as a tropical storm, and re-intensified to near-hurricane strength before being absorbed by a cold front on September 25. Meteorological history A tropical wave moved off the African coast on September 10. Shortly thereafter, it lost most of its atmospheric convection and initially showed few signs of development as it moved westward. On September 14, convection reformed near the center of the system. It continued to organize, and the next day the National Hurricane Center (NHC) classified it as Tropical Depression Twelve. At the time, it was located 470 mi (765 km) east of the Leeward Islands. By this point, the depression had a weak circulation and ragged convection. An anticyclone to its north caused the depression to move generally to the west, and upper-level conditions were forecast to be favorable for intensification. However, the circulation moved away from the main area of convection before a Hurricane Hunters flight indicated that the depression degenerated into a tropical wave on September 16. Although there was not a closed circulation, the flight observed flight-level winds of to the north and