The Ways of a Waterspout

Sun (Auckland), Volume II, Issue 323, 7 April 1928, Page 22

The Ways of a Waterspout

DANGLING funnel of vapour protrudes downward from the clouds. The water beneath, churned round in violent turmoil, hurls up a

pyramid of spray. The two meet in a slender, slate-grey column that advances majestically over the sea, spinning on its axis like a dancing dervish. Five minutes—lo minutes—and the frail shaft collapses in a momentary deluge of rain. Such is a waterspout. Fascinating to watch at the safe distance of a mile or two, the waterspout, at close quarters, is a thing to terrify the stoutest heart. -m No. mariner runs into one from choice. Records, showing that few vessels, except the smallest, have ever been seriously mishandled by these monsters, cease to be reassuring when the writhing colossus, half a mile high and scores of hundreds of feet in diameter, comes charging down on your ship. After all, the records tell only of the vessels that have survived. writes Calvin Frazer in “Popular Mechanics.”

The visible waterspout is exactly the same thing as the so-called “fun-nel-shaped cloud” of the tornado on land. There is no essential difference between waterspouts and tornadoes. It is a mere accident of language that makes most people think of them as entirely distinct phenomena. It is not uncommon for a tornado to form on land and then pass over water, becoming a waterspout. Or a spout may form off shore and travel inland, uprooting trees, demolishing houses, and giving ample evidence of the fact that it is a fullfledged tornado. The trade-wind belt is a favourite breeding ground of waterspouts, which are formed by the conflict between the easterly trades and the westerly counter-trades blowing above them. When a waterspout is forming, and while the cloud still dangles in midair, the water beneath is suddenly thrown into violent agitation. Often a saucer-like depression can be seen, around which is built up a mound of spray. This means that the aerial vortex has already pushed its way down to the water, though the visible column of vapour does not yet extend so far.

The lifting powers of waterspouts have been exaggerated by some writers and underrated by others. There is a strong updraught of air in the core of the spout. It is undoubtedly sufficient, in a big waterspout, to suck up a considerable amount of sea water to a height of several hundred feet* Tn fact, this water, thrown from the spout by centrifugal force, may often be seen

forming a lofty cataract around the base of the column. Solid objects can also be carried aloft, just as they are in tornadoes. Whether a waterspout could carry up a small boat or <»a sailor, whisked from the deck of his ship, as tornadoes sometimes carry up the roofs of houses, wagons, cattle and human beings, is unknown. Apparently no such feats have ever been recorded. It is not uncommon for waterspouts to appear in pairs or groups, and as many as 20 have been seen at one time. A very unusual case of multiple waterspouts was reported a few years ago to the British Meteorological Office by J. B. Hewitt, chief officer of the steamship Carston. About five o’clock one afternoon, while near Guantanamo, Cuba, the ship ran into a severe thunderstorm. Hardly had this subsided when the clouds began sending down tapering arms on all sides of the vessel, and several of these formed complete waterspouts. Finally there were nine large spouts, perfectly formed, within a short distance of the ship. Then a curious sight was witnessed. Around some of these spouts two or three—and in one case, four—slender, weedy-look-ing spouts were formed. They not only travelled with the big spouts but at the same time circled slowly around them, like satellites revolving about a planet. Their movements were erratic; sometimes they approached the central spout, and sometimes receded from it, at the same time undulating with great violence.

In recent years many accurate measurements have been made of waterspouts, both from ships and from shore. On December 28, 1919, a large waterspout was observed from the British steamship War Hermit. Measurements with a Sextant showed the distance between the base of the cloud and the surface of the sea to be 4,600 ft. The width of • the column tapered from 500 ft at its junction with the cloud to 150 ft at the sea. Spray was thrown up to a height of more than 300 ft over an area 250 ft in diameter. Tn this case the observers reported the spout to consist of a central column inside a hollow tube. When the spout was breaking up, the central column appeared to be lifted as a whole into the clouds, while the walls of the outer tube dissipated into spray. This double structure of waterspout columns figures in several other descriptions, but has never been satisfactorily explained. In ancient times waterspouts were believed to be Jiving monsters—dragons of the deep.