They explained the city’s geographical position made it less likely tornadoes would form and that buildings in Hong Kong were also strong enough to stand up to the high wind speed of most tornadoes.
“The key atmospheric ingredients that lead to tornado potential are warm, moist air near the ground, with cooler, dry air aloft, and wind shear,” Leung Wing-mo, a former assistant director of the Observatory, said.
“All these factors have to perfectly exist at the same time to promote the development of a tornado.
“As a matter of fact, the most severe tornadoes in China often occur in the plain region in northeastern China.”
Concerns about a possible tornado strike on the city heightened after a suburban area of Guangzhou, the capital of Guangdong province in mainland China, about a 2.5 hour drive from Hong Kong, was hit by a tornado last Saturday, which killed at least five people and injured 33 others.
More than 140 factories were damaged, although no houses collapsed, the state-run Xinhua news agency said.
A weather station in the area registered a maximum wind gust of 20.6 metres per second, or about 74km/h (46mph).
They are intense columnar vortices in the shape of funnel clouds with very strong winds and very low pressure near the centre.
They usually develop from intense thunderstorms and are severe localised phenomena which can also be accompanied by heavy rain or severe squalls.
Aaron Bok Kwok-ming, a former president of the Hong Kong Institution of Engineers, agreed there was no need for the public to become alarmed.
Hong Kong told to brace for more wet weather in week ahead
Hong Kong told to brace for more wet weather in week ahead
“The buildings in Hong Kong follow a code of practice designed to make sure they can withstand winds of speed of 200km/h,” he said. “For some skyscrapers, they are designed to withstand even strong winds of up to 300km/h.
“The tornado in Guangzhou had a wind speed of about 70km/h only – there is no need for citizens to be overly worried.”
The Observatory said tornadoes and waterspouts in Hong Kong were fairly infrequent and on average there was only one report of either about every one to two years.
The Observatory said records showed there were just 10 days with reported tornadoes between 1982 and 2023.
It added many of the reports were made during May and September. The last time the weather forecast agency received a tornado report was in September 2020.
The one before that was logged in October 2005.
Hong Kong hit with heavy rains and high winds as thunderstorm moves east
Hong Kong hit with heavy rains and high winds as thunderstorm moves east
But a tornado hit the city’s airport in September 2004 after one developed amid thunderstorms and struck at 6pm.
In a span of just a few minutes, gusts in excess of 60km/h overturned a van, injuring one.
Cargo was lifted and thrown towards a plane as it was being refuelled, damaging a fuel pipe, which caused a spill.
Waterspouts, however, are more common in Hong Kong.
There were 42 days with reported waterspouts between 1959 and last year, mainly in June and July.
The Observatory said it received a report of a waterspout off Clear Water Bay in Sai Kung last week, but that there were no reports of injuries.
