Typhoon Saola, a powerful tropical cyclone packing the force of a Category 4 hurricane, was moving northwest through the South China Sea on Thursday toward Hong Kong and the Chinese mainland.
Saola was about 229 miles east-southeast of Hong Kong on Thursday afternoon, the Chinese territory’s meteorological agency said in a warning, adding that it anticipated violent winds and heavy showers there starting on Friday.
Hong Kong issued a wind signal on Thursday afternoon that indicated winds of 25 to 38 miles per hour were in the forecast. The Chinese mainland was already under the highest level of alert under a four-tier typhoon warning system.
Saola was generating sustained winds of 155 miles per hour on Thursday, according to the Joint Typhoon Warning Center, a meteorological service operated by the U.S. Navy. That is 2 m.p.h. below a Category 5 storm on the five-tier wind scale that is used to measure tropical cyclones in the Atlantic.
Hurricanes and typhoons are tropical cyclones with sustained winds of at least 74 m.p.h. The term “hurricane” refers to tropical cyclones in the Atlantic basin; “typhoon” refers to ones that develop in the northwestern Pacific and affect Asia.
Saola has been moving through the region for days, prompting evacuations in the Philippines and school closures and travel disruptions in Taiwan. But it has not been linked to any deaths or injuries.
The storm, named for an elusive species of wild ox that is native to parts of Southeast Asia, was one of three tropical systems in the Northwest Pacific on Thursday. The others, Kirogi and Haikui, were swirling farther east, and far from land, as tropical storms.
Forecasters say it is hard to say exactly where — or if — the storm will make landfall. That is partly because Tropical Storm Haikui might influence its trajectory. Saola could also be influenced by the annual summer monsoon.
The Philippine meteorological agency said that Saola would likely move parallel to the coast of the southern Chinese province of Guangdong on Saturday, and that a landfall in mainland China was possible on Sunday.
Either way, the agency said, the storm was expected to weaken as it moved through the South China Sea, becoming a tropical storm by Monday.
There is consensus among scientists that tropical cyclones are becoming more powerful because of climate change, and that the likelihood of major ones is increasing. Climate change is also affecting the amount of rain that storms can produce.
