The Union daily times. [volume] (Union, S.C.) 1918-current, 1922-06-23
Secrets of Thunder
Storm, Cloudburst,
And Tornado Barred

New York, June 22.-Territic thun-
der storms, hailstorms, cloudbursts
and "twisters" that often sweep paths
of death and destruction during the
summer months-where do they com,
from and how are they formed?
"Ih"y originate where they cnd-a,
the surface of the Garth says Pop
uIHr Science Monthly, describing in
the July issue the scientific eXplana-
ton for various types of severe sum
mer storms. THE sun warns tire
earth, which in turn heats the lower
air. This warm, moist air, because
it is lighter than the air above, rises
in currents. Ascending, it expands
as the pressure of the surround ng air
d,minishes, and cools into water va
por that accumulates IN clouds and
floats in the air like fog, buoyed up
by rising air currents beneath.
I'm this manner are formed the
storm clouds, of strange shapes and
shades, that under certain conditions
of temperature and moisture assail
us with hailstones, rain by the buck
otfuls,' or whirlng winds.
How Hail is Formed.
"Hailstorms are simply thunder
storms in which the vertical air cur
rents within the storm cloud are Of
unusual magnitude. Hail falls only
IN connection with thunder storms.
Hailstones are formed when raindrops
are carried by the vertical currents up
into the region of freezing tempera-
lures. AS soon as the frozen drops
drift out of the area of strong up
draft, they fall bacl into the region
of liquid drops, where they become
coated with a thin film Of water. Bu;
they are again caught in the updraft
and again carried into the region of
snow and ice, where the new coating
is CONCEALED. This may happen sew
cral times, producing hailstones of
various sizes and structure. Finally
however, they become too large to be
sustained by the ascending currents
whercupon they fall to earth.
'Somctimes the hailstones, whe 4
broken through the center, show
plainly the series of concentric she'll;
manner described.
"CloudburSts are simply heat thun.
der storms in which the rainfall is un-
usually great. Heat thunder storms
are those caused by the rising, coolin"
and condensation of large masses OF
warm, moist air. AS condensation
continues the cloud becomes larger
and larger, finally becoming a thun-
der storm. The drops of water within
the cloud also grow larger and larger
until finally they become too large to
be sustained by the upward currents
whereupon precipitation begins.
The Origin Of Cl0udbursts.
zone interesting hut as yet unox-
planned fact in the movement of thm-
der storms is that they are unable to
cross large rivers. In some cases this
probably accounts for the rainfall
reaching cloudburst proportions. The
storm, reaching the river, is stopped
and held stationary for a time, so
that the unusually heavy rate Of
rainfall usually present near the front
Of the storm, is continued over the
same territory for much longer tim"
than usual. Sometimes large noun.
tains cause the storms to stand still.
thus creating cloudbursts.
"The tornado appears to be causn.l
by an unusually violent development
of upward air movements in clmulo-
rimbus or storm cloud. This upward
rushing of warm air, under certain
conditions may become strong enough
to form a whirl or eddy within. the
cloud. This air whirl, when once set
up within the cloud, readily extends
downward.
"The centrifugal force Of the
whirling air creates at the center a
partial vacuum in which some of the
moisture in the air condenScs, form
ing funel- shaped cloud"