Boat skipper trawling a boat with his crew members for tuna fish about 57 nautical miles off the Ghora Bari coast of Sindh recorded the rare weather phenomenon of waterspout earlier this week, the WWF-Pakistan said on Tuesday.
The oceanic spectacle that shows up rarely and resembles the tornado, skipper Saeed Zaman captured through lenses last Monday, Jan 21, 2019. "This rare weather phenomenon was previously reported by fishermen on 28 February 2016 near Sakoni off Kalmat Khor, Balochistan," the WWF-Pakistan said.
Unfolding the story, Zaman said that he sighted in the morning to a massive waterspout swirling to his boat suddenly but succeeded to drift away, saying that it first looked like a huge patch of cloud. He said that the waterspout was latter seen descending. None of the other boats fishing in the same area also were unmoved to reach the waterspout.
Muhammad Moazzam Khan, Technical Advisor on Marine Fisheries at the WWF-Pakistan, the waterspouts are usually formed along the cumulus type of clouds. "This type of waterspout is generally not associated with thunderstorms which usually dissipate in short time," he said, adding that waterspouts have long been recognized as serious marine hazards. Stronger waterspouts pose threat to small boats.
He said that fishers maintain a considerable distance from such a phenomenon. "The average spout is around 50 metres in diameter, with wind speeds of 80 kilometres per hour," he said, adding that "the most waterspouts last for up to one hour, though the average lifetime is just 5 to 10 minutes".
The formation of a waterspout takes place over five stages; the first stage is the formation of a disk on the surface of water, known as a dark spot; the second stage is a spiral pattern on the water surface; the third stage is a formation of a spray ring; the fourth stage is where the waterspout becomes a visible funnel; and the lifecycle ends and fifth stage where the waterspout decays.
WWF-Pakistan appreciated the alertness and vision of the fishermen who have been trained to record such rare events including release of endangered marine animals. Contrary to its name, a waterspout is not filled with water but is a column of cloud-filled wind rotating over the ocean's surface.
It descends from a cumulus cloud and the water inside a waterspout is formed by condensation in the cloud. There are two types of waterspouts including tornado and fair-weather.
The clouds from which waterspouts descend are not fast-moving, so fair-weather waterspouts are often static. Both waterspouts require high levels of humidity and a relatively warm water temperature compared to the overlying air. Waterspouts are most common in tropical and subtropical waters but this is the second authentic record of its occurrence from Pakistan coast.