The Bridgeport evening farmer., 1917-09-17
IS TORNADO SEASON WEATHER
 BUREAU WARNS
Tells Time They Occur With
 Causes and Effects.

Washington. D. C., Sept. 1.-The larly favorable to the development of tornadoes, according to the United States Weather Bureau, which issues a series of warnings and definitions of tornado conditions
 It says that tornadoes are usually. preceded by high temperature and humidity-a weather condition gener- ally said to be 'sultry,' sticky" or oppressive" Rain may come be- fore, with, or after a tornado, or, very rarely, there may be no rain at all. The barometer does not fore tell a tornado though it indicates low pressures; and tornadoes always oc- cur in low area.
 The season in which tornadoes may be expected varies according to the re- zion. They may visit the Gulf States in winter, and as the season advances the region of greatest frequency is ! the Plains States and the Mississippi Valley, from April to September in- elusive. In this region May is the worst month, with April next East of the Appalachian Mountains, how ever, tornadoes rarely occur until af- ter July. Generally they come be- tween s.30 and 500 p. m., but they may even come at night.
 What to Do.
 Persons may somewhat avoid torna- do danger, by watching the local signs and reading. the weather maps which at least show the conditions which favor tornado formation. The local signs are heavy, dark clouds, first in the southwest, almost immediately fol- lowed by clouds in the northwest and north. A funnel-shaped cloud is a sure sign, though there may be 9 tor nado when such a cloud is not readily seen. If a funnel cloud cannot be seen, the whirling Lotion of the air may be known by a peculiar roaring noise, somewhat like the rumble of
 distant thunder or the approach of a heavy train of cars.
 If one can see the cloud and get an idea of the direction in which it is
 moving, the zone of safety is at right angles to the direction of motion The
 southern margin is usually more dan gerous than the northern, and this should be remembered in seeking a place of safety. The width of the path of greatest destruction is ordin- ari1y no more than few hundred yards, though this destructive diame- ter may be from some rods wide to a half mile, or sometimes wider. How ever, the worst part is comparatively narrow and relative safety may be had only a short distance at right an- gles to the line of the advance of the | tornado.
 In some of the plains states there are so-called "cyclone'' cellars, and where these are not available the southwest corner of the cellar of a frame building is the next best place. Brick buildings are not so safe, but l the cellar is probably the safest place l in them. In the Omaha tornado of 1913 very few brick houses were seri- olrs1y damaged. These are ordinarily l unroofed, though sometimes the walls l crumble or fall. outward.
 Tornadoes and Cyclones. l Weather men define a. tornado as a I violent windstorm with rain or hail,
 thunder and lightning. in which the air masses whirl with great velocity around central core while the whole
 storm travels across the country in a
 narrow path at high speed. The
 thunder and the whirling motion have 1 given rise to two theories of the deri-
 vation of the word; as to whether it is l derived from the Spanish tornado, ,'
 a thunder storpn, or from the Latin | "tornara," to turn. I,
 l A cyclone; in the definition of the | Weather Bureau, is not necessarily a windstorrn of great velocity, but rath- CT widespread storm that moves
 with no great aspeed. It's width may cover several states. This cyclone | or area of low pressure-indicated as l low on the weather map-gives con- I ditions essential to, tornadoes. Many l cyclones never develop a tornado, but
 a tornado never develops without the 1 cyclone, and almost invariably the tor
 nadoes occur in the southeast quar- ter of the low area. About 120 cy- I clones pass across the United States
 each year, moving in a general way l from west to east: They are of great I benefit because they induce a move | ment of surface air from the south and southeast, and the rainfall that
 makes the great interior valleys rich ! agricultural region is dependent upon | theseg southerly, moisture -bearin | winds.
 Practically all of the cyclones of l the warm season give rise at some time or place to thunder storms, or l hail or violent winds. These winds | may be violent enough to cause de- struction, but unless they have the l whfrling column of air they are not l tornadoes- In the East it is not al- ways easy to distinguish the funnel l shaped cloud, but the lay of the de- | bris after storm will tell whether there has been twisting motion Tornadoes almost invariably move | in an easterly direction and generally | from southwest to northeast. The average length of the path of destruc- l ton is about 25 miles, and this path l may not be continuous, if the funnel cloud is not in contact with the earth during it's whole course. Sometimes | it rises and goes for a considerable dis l tance before descending again. | CENTRAL AVENUE MAN