Super Typhoon Mangkhut is predicted to be one of the strongest storms to ever hit the city and presents a “great danger to Hong Kong”, a top weather expert said.
The storm, which is forecast to be more powerful than any of the previous typhoons warranting Hong Kong’s highest warning signal, is predicted to pass within 100 kilometres of the city on Sunday.
Queenie Lam Ching-chi, senior scientific officer at the Hong Kong Observatory, said even if the super typhoon was further away, it could impact the city.
But, the forecaster’s tracking system shows a 70% chance the tropical cyclone will deviate from its predicted path over the next four days.
According to the latest update at 8am on Wednesday, the super typhoon is expected to be closest to the city on Sunday, about 100 kilometres southwest of Tsim Sha Tsui, where the Observatory has its headquarters.
Lam Chiu-ying, a former director of the Observatory, said there was still a lot of uncertainty about Mangkhut’s path because it needed to first pass through the narrow Luzon Strait between Taiwan and the Philippines before hitting Hong Kong.
“Its intensity can be reduced if it hits land on either side [of the strait],” Lam said. “Since it’s still so far away from Hong Kong, its path can easily deviate several hundreds of kilometres from the predicted path.”
Lam, meanwhile, said it was still too early to say whether Mangkhut would directly hit the city.
“But it could be very close to Hong Kong,” she said. “It has a large circulation with intense winds, so even if it’s not a direct hit, there could still be an impact on Hong Kong.
“It can constitute a great danger to Hong Kong.”
Lam said the weather on Sunday would be “relatively adverse”, with low-lying areas facing risks of flooding and seawater intrusion. She advised citizens to take typhoon precautions beforehand.
She added that the Observatory would issue “appropriate warning signals based on the actual situation”.
A typhoon is often referred to as hitting Hong Kong directly if it passes within 100 kilometres of the city.
Forecasters predict that if it maintains its present course then at 8am on Sunday the typhoon will be about 240km southeast of the city, with winds reaching some 220 kilometres per hour.
However, while the forecast path of Mangkhut indicates the most likely track the super typhoon will take, the actual path may deviate significantly, especially considering the typhoon is at least three days away.
The Observatory’s tracking system shows a 70% probability that Mangkhut could deviate within a 500 kilometres radius from its predicted position closest to the city, leaving a lot of uncertainty over the next few days.
Even so, the forecast wind speed is predicted to be the strongest since records began in 1946, and stronger than any of the 15 past severe or super typhoons that warranted the highest No 10 warning signal.
Under the tropical cyclone classification system, typhoons have an intensity of between 118 and 149km/h, severe typhoons range between 150 and 184km/h, while super typhoons see a maximum wind speed near the centre of 185km/h or above.
A No 10 tropical cyclone warning signal indicates that a typhoon’s intensity is expected to reach at least 118km/h, and gusts may reach 220km/h.
Super Typhoon Hato in August last year, for example, prompted the Observatory to issue the No 10 signal. It reached 185km/h at its peak intensity.