Photos of funnel-shaped clouds spinning were uploaded on social media sites yesterday on the 9th, and it was suspected to be the rare astronomical phenomenon – waterspout, which is a rotating column of water and spray formed by a whirlwind occurring over the sea or other body of water. However, the Hong Kong Observatory pointed out that the clouds photographed by the public did not extend to the land and sea, and hence would only be considered as a whirling funnel cloud instead of a waterspout.
According to the past record in Hong Kong, funnel cloud could evolve into waterspout, and could even develop into the stronger tornado. In 1982, two Hong Kong citizens were carried away and killed by tornado and five were injured. The National Oceanic and Atmospheric Administration from the United States reminds that, one should move 90 degrees away from the direction of the waterspout if he or she spots one. Do not go near and study it as the risk of some waterspouts is similar to that of tornadoes.
Hong Kong citizen, Simon Wong, was in Sai Kung Town around 6:24 pm overlooking Tathong Channel yesterday, and photographed pictures of the bizarre-looking clouds that were suspected to be water tornado and uploaded them to a Facebook group. The senior scientific officer from the Hong Kong Observatory, Leung Yan Yu, replied that waterspout and tornado both belong to whirling clouds, which usually happen between May to October when the weather is unstable.
According to the record of the Observatory, there have been 9 reporting days of tornado in Hong Kong since 1982, whilst there were 35 reporting days of waterspout, which is over three times more. Leung explained that the higher water content in the sea would promote the formation of clouds, which then has a higher chance to develop into unstable weather. The surface area of the ocean is also larger, therefore the frequency of waterspout is higher than that of a tornado on the land.
Although the frequency of waterspout and tornado is not high in Hong Kong, it could kill and injure when it happens. In 1982, the tornado in Yuen Long caused two deaths and five injured. The waterspout in 1986 tossed over two fishing boats and all four people on the boats were drowned and found dead. The latest waterspout in Hong Kong happened in October 2015 near Kau Yi Chau, and fortunately did not cause any casualties.