The Waxahachie daily light. [volume] (Waxahachie, Tex.) 1894-current, 1908-05-22
HOW TORNADOES COME TO LIFT,
Atmospheric Freaks Occurring in
| the Spring or Summer Months

Atmospheric Freaks Occurring in
the Spring or Summer Months
The late violent storms in the
south are believed to have been at
tended with the loss of 500 lives.
The damage was done partly by hur-
ricanes, partly by tornadoes, often
though wrongly, called cyclones,
says the Galveston Tribune.
In modern usage the cyclone is
vast atmospheric eddy about cen
ter of light air which is indicated
by low barometer. The heavier
air rushing toward the center from
all sides produces the same sort of
an eddy that follows the removal of
a stopper from a washbowl. The cy-
clone is usually from 1000 to 1900
miles in diameter The winds it
causes, vary from a gentle breeze to
a gale. Their violence depends on
the difference in air pressure in the
center from about the circumference
Into its swirling vortex are sucked
| the moisture laden currents from the
Gulf of Mexico, so that the passage
| of cyclone gives southerly winds
and under proper conditions rain.
| The tornado is one of the COM
paratively rare incidents in the his
tory of a cyclone when set
of peculiar conditions are satisfied,
| 1t is mass of air from 100 to 1000
| feet in diameter revolving at terrific
speed. Usually it travels only few
miles before it disappears
This freak of nature occurs ordi-
narily only in the spring or early
| summer. when the earth and the
stratum of air Immediately above it
are. heating rapidly The upper air
is still intensely cold from the eff
fects of winter. Warm air expands
and SO becomes light and tends to
rise. Cold air contracts, is heavy
and falls.
Ordinarily the different strata of
air coming gently with no distur-
bance. But sometimes the great ed
dy of the cyclone brings down mass
es of cold air from it's western side
upon the hot surface winds of the
southeast quarter. Then there is
trouble.
The hot, rarefied, air surrounded
by heavy cold envelope shoots up
ward. The heavy air rushes in to-
ward the semi-vacuum in the center
Once more there is the effect of the
wash bowl with the stopper out
AS the water nears the center of
the bowl circles with increasing ra-
pidity so the air particles move with
accelerated speed near the center of
the tornado so that the energy de-
veloped sweeps away houses and up
roots trees The velocity of the air
close to the center is known at
times to equal that of a modern rife
bullet
The weather bureau outlines four
conditions as essential to the forma-
ton of tornado near any given
place. First, a cyclone, or area of
low barometer the center of which
is to the north of northwest; second
a temperature of about 70 degrees
at O'Clock in the morning; third.
great humidity; fourth that the
time of year be between April | and
July l.
The conditions are so we'll known
that the various weather stations
are able TO send out effective warn
lngs. For instance, on the morning
of May p, 1896, the day of the St.
| Louis tornado, the abnormal heat
and humidity and the aspect of the
area of low barometer on the map
caused the bureau at 10 O'Clock to
send out warnings through Missouri
and eastern Kansas.
The hurricane is an enlarged tor
nado. It's diameter is usually from
! 100 miles to 500 miles and the whirl
is correspondence less violent than
the tornado's. The storm that de-
wasted Galveston in September, 1900,
was hurricane. 1t was first observed
September l off Porto Rico. Three
days later its center reached Cuba,
September it was at Key West,
the next day east of New Orleans
and September at Galveston. 1t
curved then to the north through
! Oklahoma City and then travelled
northeast by way of Des Moines,
| Milwaukee and Lake Ontario.
The weather bureau storm warn
! ings were of enormus value to ship