Typhoon Prapiroon, known in the Philippines as Tropical Storm Henry, was a minimal typhoon which caused deadly flooding in southern China in August 2006. Prapiroon developed out of a persistent area of convection accompanied by an area of low pressure on July 25 about 120 km (75 mi) west-southwest of Yap. Two days later, both the Japan Meteorological Agency (JMA) and PAGASA classified the system as a tropical depression, with PAGASA giving it the local name 'Henry'. By July 31, the Joint Typhoon Warning Center (JTWC) classified the system as Tropical Depression 07W. A strong subtropical ridge located to the north of the depression led to a west-northwest movement for most of the storm existence.