Another night of thunderstorms and rainstorm and the fact that the Hong Kong Observatory reported that an El Niño event was very probable this year got me thinking about extreme weather in a Hong Kong. We all know that Hong Kong gets hit by typhoons ( = hurricanes to Americans and British, Cyclones to Australians). You probably also know that typhoon systems form over warm oceans. But you might not know that Hong Kong also has tornadoes that form over the sea. These are so called water spouts and while they are very short-lived (15-20 minutes generally) compared to typhoons (days, even weeks) they are still quite fierce. Other than Hong Kong, I know of at least two other places where water spouts are common: the Florida Keys (saw it on a twister documentary) and the Philippines were I saw 3 in one day in April.
A waterspout occurring on the 21st August 1986 capsized two fishing boats causing four crew members to drown. On 18 August 1982, another waterspout occurred along the southern coast of Tsing Yi Island. Though no one was injured or killed by this waterspout, fourteen or more 4-tonne containers were blown upwards to the sky and the rooftop of a nearby empty house was ripped from its building.
The last water spouts spotted on Hong Kong occurred on two days in July 2010. A water spout was reported off Siu Sai Wan (east Kowloon) on the 22nd of July and a funnel cloud and at least three water spouts were sighted in Deep Bay on the 27th July 2010.
YouTube video of the water spouts in Deep Bay / Shenzhen Bay on the 27th of July 2010
A waterspout occurs over water, whereas a tornado is its equivalent over land. It usually involves a fast rotating column of air extending from the base of a cloud to the water surface. A rotating column of air that does not touch the water surface is called a funnel cloud and is made visible by cloud droplets.
In Hong Kong, there have been a total of 40 reports of waterspouts sighted within 460 kilometres of Hong Kong since 1959. Waterspouts are more commonly seen in June and July, so the season of the Dragon Kings is approaching…Dragon King?
In Chinese mythology there are deities called the Dragon Kings (龍王) which are regarded as the divine rulers of the oceans. They appear often in classical Chinese literature and apart from having shapeshifting abilities and living in an underwater crystal palace, they also commands various marine creatures. They are the rulers of moving bodies of water, such as the sea and can show themselves as water spouts.
Now you might wonder: what this weather phenomenon has to do with marine biology? On the 6th of May the BBC reported that a village in west Sri Lanka was surprised and delighted by an unusual rainfall of small fish. The fish fell during a storm and were believed to have been lifted out of a river during a strong wind. Apparently the “fish fall” had a total weight of 50kg (110lbs). And it’s not the first incident in Sri Lanka – in 2012, a case of “prawn rain” was recorded in the south.
“Scientists say that “fish rain” usually occurs when swirling whirlwinds over relatively shallow water develops into waterspouts and sucks in almost anything in the water including fish, eels and even frogs. The marine life can be carried long distances by buffeting clouds even when the waterspout stops spinning.”
As far as I am aware there has not been any recorded “fish rain” or “prawn rain” in Hong Kong. But now that you now know about water spouts in HK and fish rain, you will be able to explain it to friends if suddenly one June or July you get soaked in sea-bream…