Pine Bluff daily graphic., 1917-09-23
WEATHER SHARES
 ISSUE WARNING
 AGAINST STORMS
Federal Bureau Experts Say Season Favorable for De-
 velopment of Tornadoes.

l season is particularly favorable to the development of tornadoas, according te the weather experts of the department of agriculture, which has issued 6 bulletin giving warnings and descrip- tlons of storm conditions.
 It says that tornadoes are usually preceded by high temperature and humldity-a weather condition gener- ally said to be "sultry," sticky" ol Oppressive" Rain may come before with, or after tornado, or, very rare lly, there may be no rain at all. The barometer does not foretell tornado though it indicates low pressures; and tornadoes always occur in a "low'' area.
 The season in which tornadoes may be expected varies according to the region. They may visit the Gulf states in winter, and as the season advances, the region of greatest frequency is in the plains states and the Missis- sippi valley, from April to September inclusive. 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 3:30 and p. m., but they may even come at night.
 Persons may somewhat avoid tor nado 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 immedi- ately followed by clouds in the North west and North. A funnel-shaped cloud is sure sign, though there may be a tornado when such a cloud is not readily seen. If a funnel cloud cannot be seen, the whirling motion of the air may be known by peculiar roaring noise, somewhat like theI rumble of distant thunder or the ap- proach of heavy train of cars.
 If one can see the cloud and get an idea. of the direction in which it isl the zone of safety is at right angles to the direction of motion, The 1 southern margin is usually more dangerous than the northern, and this should be remembered in seeking a l place of safety. The width of the path of greatest destruction is ordin- arify not more than a few hundred | yards, though this destructive diamc- ter may be from some rods wide to a half mile, or sometimes wider.
 In some of the Plain states there are so-called "cyclone" cellars, and where these are not available the southwest corner of the cellar of a frame build- ing is the next best place. Brick buildings are not safe, but the cellar IS probably the safest place in them.
 Weather men define a tornado as l violent windstorm with rain or hail. thunder and lightning, in which the air masses whirl with great velocity .round a central core while the whole storm travels across the country in a narrow path at high speed. /,
 A cyclone, in the definition of the 1 weather bureau, is not necessarily a vindstorm of great velocity, but rath- ( r widespread storm that moves with 10 great speed. Its width may cover everal states. This cyclone, or area t # low pressure-indicated as "low" on ' he weather map-gives conditions es- entlal to tornadoes. Many cyclones W ever develop tornado, but a torna- $ o never develops without the cyclone, nd almost invariably the tornadoes CCuI III CuC SOutHcdSC quarter or the ow area. About 120 cyclones pass i cross the United States each year, f 1oving in general way from west to ast. They are of great benefit be- l. ause they induce movement of sur- f. ace air from the south and southeast, n nd the rainfall that makes the great ! lterior valleys rich agricultural :, ,gion is dependent upon these south v rly, misunderstanding winds. ' Tornadoes almost invariably move ! an easterly direction and general 7 from southwest to northeast. The verage length of the path of destruc- :, on is about twenty-five miles, and z lis path may not be continuous. if the ~ ~ lnnel cloud is not in contact with the a' arth during it's whole course. Some mes it rises and goes for a consider si ole distance before descending again. ei el A VALUABLE HEALTH HINT.
 Foley Cathartic Tablets keep the h. h.