What typhoon struck China in 2012 approached within 800 km of Hong Kong and posed a threat of deteriorating conditions in Hong Kong?
Typhoon Vicente: Typhoon Vicente, known in the Philippines as Tropical Depression Ferdie, was regarded as the most powerful storm to strike southern China in recent years, as it made landfall as a powerful category 4 equivalent-typhoon. Typhoon Vicente:  Vicente soon steadily moved into the South China Sea, and began to intensify above warm sea waters, and began explosive intensification early on July 23, and started to charge toward the Guangdong region prompting the Hong Kong Observatory (HKO) to issue the Hurricane Signal, No. 10, the first since York in 1999. Hong Kong tropical cyclone warning signals:  The Hong Kong Observatory issues the warning signal if a tropical cyclone approaches within 800 km of Hong Kong and poses a threat of deteriorating conditions in Hong Kong.
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