Category 4 Typhoon Saola is lashing Hong Kong and mainland China

Typhoon Saola – the equivalent of a Category 4 hurricane – is battering Hong Kong with a deluge of rain, destructive winds and a possible record ocean surge. The intense typhoon is also poised to lash coastal southeast China. Transportation, government, businesses and schools have come to a halt across the region.

As Saola neared one of the world’s largest coastal cities, the Hong Kong Observatory issued a Storm Signal No. 10, the highest level on its 1 to 10 scale.

“The eyewall of Super Typhoon Saola is now moving across Hong Kong, posing a high threat to Hong Kong. Hurricane force winds are affecting the eastern part of Hong Kong,” the observatory wrote in an online bulletin Friday evening local time. “Members of the public should stay on high alert. You are advised to remain where you are if protected and be prepared for destructive winds.”

The eyewall is the ring of torrential rain and destructive winds that surround the typhoon’s calm center or eye. Hong Kong is now under the western side of the eyewall as the center remains just offshore.

Gusts more than 110 mph reached Waglan Island, just offshore of Hong Kong, on Friday evening, the observatory reported.

The storm is bombarding the area as a weakening but powerful typhoon after a peak intensity of 150 mph Thursday, when it was briefly considered a super typhoon.

Still packing 140 mph winds, Saola was about 20 miles offshore of Hong Kong early Friday evening local time and moving toward the west around 10 mph, according to the Joint Typhoon Warning Center.

Typhoons in the northwest Pacific are the same as hurricanes in the tropical Atlantic. Typhoons whose maximum winds reach at least 150 mph are called super typhoons.

Schools, businesses and the Hong Kong stock market closed Friday in advance of the storm, according to Reuters. The city’s chief executive, John Lee, posted to Facebook that he has requested all city units be deployed to manage the storm threat.

China has suspended 121 passenger trains in the region through Sept. 6, according to the Associated Press. The AP also said that fishing boats were called to port, while cities near the potential landfall point in Guangdong Province stopped most activities until an all-clear.

While very intense, Saola is a fairly compact system. The most recent advisory showed hurricane-force winds are confined to within 25 miles of the center and tropical storm winds largely within 100 miles of the center.

In addition to the strong winds, flooding rainfall of 6 to 12 inches is a risk in the hardest-hit spots around Hong Kong and Macao, then inland around Shenzhen and Jiangmen in Guangdong Province. The rapid accumulation of heavy rain may cause urban and river flooding, as well as landslides.

A life-threatening storm surge – a rise in ocean water above normally dry land – is expected for low-lying coastal areas, regardless of any weakening. “The maximum water level may reach a historical record. The worst hit areas include Sha Tin, Tai Po, Sha Tau Kok, Sai Kung, etc. There will be serious flooding, the flood depth in some areas may be more than [3.3 feet],” the observatory warned.

Waves were up to 46 feet high around the center of the storm early Friday, according to typhoon warning center reports. The observatory said that “seas will be phenomenal with swells. Members of the public are advised to stay away from the shoreline and not to engage in water sports,” the observatory said.

The storm may be among the most intense to make landfall in the region in modern history. Even a scrape from such a storm is significant.

The broader region sees a tropical storm or typhoon threat about once every two years on average. Hong Kong is a rather small target. Its last direct storm landfall was Nuri in 2008, which hit as a tropical storm after peaking as a Category 3 typhoon earlier.

Typhoon Hato in August 2017 caused the closure of much of Hong Kong as it passed to the southwest, causing numerous injuries and leaving widespread damage across the region. Dujuan took a path across northern Hong Kong as a Category 2 typhoon in September 2003, but the worst conditions affected areas to the north in mainland China.

Trailing Saola is yet another typhoon. Named Haikui, it is forecast to sweep across Taiwan on Sunday and then slam into China on Tuesday, well to the north of the zone being affected by Saola.