East Oregonian : E.O. (Pendleton, OR) 1888-current, 1917-09-20
WHAT A TORNADO
is AND HOW TO
ESCAPE INJURY

WASHINGTON, Sept 2O.--The
present season appears to be partic-
ularly favorable to the development
of tornadoes, according to the United
States weather bureau, which issues
a series of warnings and definitions
of tornado conditions.
1t says that tornadoes are usually
preceded by high temperature and
humidity weather condition gem
orally said to be "sultry," Sticky"
or Oppressive" Rain may come be-
| fore, with or after tornado. or
very rarely. there may be no rain at
all. The barometer does not foreteil
tornado though it indicates low
pressure; and tornadoes always oc-
cur in 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 fire.
quency Is in the Plains states and the
Mississippi valley, from April to Sep
tember inclusive. In this region May
| IS the worst month, with April next
East of the Appalachian mountains,
however, tornadoes rarely occur un-
til after July. Generally they come
between $3.50 and 500 p. m. but
they may even come at night.
What to Do.
Persons may somewhat avoid tor
nado danger, by watching the local
signs and reading the weather maps,
which at least show the conditions
favorable to tornado formation. The
local signs are heavy, dark clouds,
first in the southwest. almost imme-
diately followed by clouds in the
northwest and north. A funnel-shape
cloud is a sure sign, though there
may be a tornado when such cloud
is not readily seen. If a funnel cloud
can not be seen, the whirling motion
of the air may be known by a pecul-
lar roaring noise, somewhat like the
rumble of distant thunder or the ap
proach 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 the motion.
The southern margin is usually more
dangerous than the northern, and this
is ordinarily not more than few
hundred yards, though this destruc-
tive diameter may be from some
rods wide to a half mile, or some
times wider. However, the worst
part is comparatively narrow and
safety may be had only a short dis
tance at right angles to the line of
the advance of the tordano.
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
frame building is the next best place.
Brick buildings are not so safe, but
the cellar is probably the safest place
in them. In the Omaha tornado o.
1913 very few brick houses were Sc
riously damaged. These are ordinar-
lily unroofed, though sometimes the
walls crumble or fall outward.
Tornadoes and Cyclones.
Weather men define a tornado as
a violent windstorm with rain or hail,
thunder and lightning, in which the
air masses whirl with great 'veloc-
ity around a central core while the
whole storm travels across the coun-
try in a narrow path at high speed.
The thunder and the whirling motion
have given rise to two theories of
the derivation of the word; as TO
whether it is derived from the Span
ish "tronada," a thunder storm, or
from the Latin "tornare." to turn.
A cyclone. in the definition of the
weather bureau, is not necessarily
windstorm of great velocity. but