Democratic Sentinel, Volume 20, Number 15, Rensselaer, Jasper County, 17 April 1896 — HOW A STORM IS BORN. [ARTICLE]

HOW A STORM IS BORN.

lt» Parent is the Sun, While Rain and Snow Are Only Its Companions, How storms are born and how they start on their journeys, is something few persons besides weather sharps know anything about. Sergeant aud “Farmer" Elias B. Dunn held forth most interestingly the other afternoon ou this subject. The wind was blowing at.the rate of sixty to eighty miles an hour through the streets, and. it seemed, with even greater force up outside the tower of the Manhattan Life building. Overhead was the bluest sort of sky, the weather was crisp and cold, and save for the sharp whistling and crackling of the | wind it would have been a perfect win-| ter’s day. "Yet," said Sergeant Dunn, "this is | what is scientifically known as a storm, i People generally think that a storm is the rain and snow, but they are not ' the storm itself, only occasional accoin- : paniments of it. Storms are the movements of great currents of air over vast ; areas. The sun begins them all, its i beat gathering up the moisture and whirling it through the air. Storms are the battles between great areas or banks of low and high pressures." “Now, as to what causes or brings about the birth of a storm. Storms are generated where there is excessive heat and moisture. They are built up in various ways, at times being formed rapidly and at times slowly, .lust how they start, just what is their very beginning, it is not always possible to say, for on occasion they are formed In a great circle, and again in a very small center. But the general principle Is this: From some cause or other, the heat of the sun gathers up so much moisture that at a certain point in the air there begins to be a great bank of atmosphere that is warmer and damper than the current immediately surrounding it. The heat, carrying the moisture with it, ascends in a column, and as it rises and commences to spread gathers with it more and more moisture. "These are called centers of low pressure. They are to be found In till parts of the atmosphere, near the earth, or miles above It. It Is quite possible for a , storm to l>e raging up hi the clouds, ami yet not. be felt on the surface of the ground. So, nTso, there might be a serious storm near to the earth that would have no effect upon the upper currents of air. Science. It. Is interesting to know, has never liven able to determine precisely how far the atmosphere extends above the earth. It Is commonly believed among sclent Hie meu now that the atmosphere’s height varies according to certain conditions. It is thought to be nt least fifty miles above the earth, and it Is supposed that at times It may extend two hundred miles up. lam talking now, understand, with regard to cyclones only. These low pressure areas of storm are in vast extent, and they have two motions—first, their progressive or onward motion from west to east nt a rate of about twenty-tflve to thirty miles an hour; and, second, the spiral centripetal movement of their moisture-soaked air currents at eighty to ninety miles an hour. “As this great bank of winds of terrific force, with its curving, circling motion, moves along, the heated air feeds on the moisture It can pick up in its flight. The more moisture it can get the greater the intensity of the storm. Should its course lie over dry and arid regions, little by little the violence of the winds would decrease, but if it is moving over a seaboard district, where it can suck moisture from the surface of the water, its power may grow to almost tiny point. "Opposed to tills are the areas of high pressure, banks of cold, dry air, which condense the moisture when they come in contact with It. That is, they will condense unless the area of low pressure Is too strong and is under too favorable conditions to be done away with. This is the great battle thait is constantly taking place In the air •a'bove us. "The high pressure areas keep forcing themselves upon those of low pressure, their currents of cold,dry air having a tendency to dissipate and destroy the moisture-laden clouds of the cyclone, or to drive it onward. “Tornadoes are a different sort of storms. They are formed on the south, or southeast quadrants, or portions, of fln area of low pressure in the warmest part of the day, and in some instances are caused by warm, moist air from the south clashing with currents of cold, dry air. These two currents are frequently thirty to forty degrees of temperature apart. Their clashing causes an almost instant displacement of the air, ami the battle between them is brief while often terrible in its effects. This conflict of the currents is the tornado. Its conflicting and battling Winds may be likened to an enormous screw witli Its point resting upon the earth and moving along at an enormous rate of speed.”