Typhoon Wipha, the sixth typhoon of the year, strengthened to a severe tropical storm around 5:00 on Saturday, according to the China Meteorological Administration, which renewed a yellow alert.
In the early hours of Friday, a tropical depression east of the Philippines strengthened into Wipha to the level of a tropical storm.
The tropical storm is moving northwestward at a speed of 25 kilometers per hour and is expected to intensify.
It is projected to make landfall along coastal areas between Shenzhen City of Guangdong Province in south China and Wenchang in the southern tropical island province of Hainan between Sunday afternoon and evening.
As Wipha approached, China's Ministry of Water Resources launched a Level-IV emergency response to flooding in the coastal provinces of Guangdong, Guangxi and Hainan on Saturday. Guangdong activated a Level-IV emergency response for strong wind on Friday.
Shenzhen on Friday issued its first red alert for rainstorms this year as the city began to experience heavy thunderstorms and strong winds.
The Guangdong Maritime Safety Administration on Friday activated a Level-IV emergency response to tropical cyclone, which was upgraded to Level II on Saturday morning.
A total of 24 shipping routes and 89 passenger ferries in the province's coastal waters were suspended as of 16:00.
East China's Fujian Province, located in the outer sphere of Wipha, launched a similar emergency response on the same day.
Three sea ports in Haikou, the capital of Hainan, are scheduled to suspend operation starting 21:30 on Saturday.
Maritime authorities in Guangdong are intensifying efforts to evacuate personnel from offshore construction platforms and marine ranches to ensure safety.
So far, a total of 12,000 offshore workers have been evacuated, and 523 offshore fishing boats have returned to ports for shelter.
China has a four-tier emergency response system for flood control, with Level I being the most urgent response, and a four-tier, color-coded weather warning system, with red representing the most severe warning, followed by orange, yellow and blue.
Typhoon Wipha strengthens to severe tropical storm, triggers emergency response
