Super Typhoon Ragasa - the strongest storm of the year is about to make landfall: Hong Kong braces itself to cope, Southern China evacuates hundreds of thousands of people

People have flocked to supermarkets to stock up on essentials, leaving many shelves empty amid fears that stores could close in the next two days.

In homes and office buildings across the city, windows are taped shut in hopes of minimizing damage if the glass breaks.

Typhoon Ragasa, with winds of up to 220 km/h, is posing a "serious threat to the coast of Guangdong", the financial hub's neighbouring province, the Hong Kong Observatory said.

The typhoon is expected to maintain super typhoon intensity as it moves closer to the Guangdong coast and will affect Hong Kong, mainland China and Taiwan after passing north of the Philippines on September 22. It is expected to make landfall on the Guangdong coast between noon and late September 24.

Guangdong provincial authorities have evacuated more than 370,000 people, Xinhua news agency reported on September 23.

At 2:20 p.m. local time, Hong Kong issued a typhoon signal number 8, the third highest level, requiring most businesses and transport services to cease operations. More than 700 flights were affected, including in Macau and Taiwan.

The weather is forecast to deteriorate rapidly later on September 23 and the Observatory said it would assess whether to issue a higher warning late on September 23 or early on September 24.

Sea level rise warning

Strong winds offshore and over high ground are expected in Hong Kong on September 24, along with heavy rains that are expected to cause significant storm surges and sea level rise. The observatory warned of sea level rise similar to that seen during Typhoon Hato in 2017 and Typhoon Mangkhut in 2018, both of which caused billions of dollars in damage.

Water levels will rise by about 2 metres along Hong Kong's coastal areas and maximum water levels could reach 4 to 5 metres in some areas.

Reaction from the regions

In mainland China:More than 11 cities in Guangdong, including the tech hub of Shenzhen and the coastal city of Zhuhai, have suspended work, transport services and schools. The China National Environmental Forecasting Center said the waters off Guangdong would see huge waves of up to 7 meters high.

In Macau:Bracing for significant impacts, all casinos will be forced to close by 5 p.m. local time as the special administrative region raises its storm signal to level 8.

In Taiwan:Nearly 60cm of rain was recorded in the eastern mountains and 25 people were injured, while transport disruptions continued for a second day with 273 flights cancelled.

Hong Kong's stock exchange will remain open, after changing its policy late last year to continue trading regardless of weather conditions.