The Democratic advocate. [volume] (Westminster, Md.) 1865-1972, 1885-10-31
Something About Tornadoes.
How They Originate, What They Are,
and Their Area Of Destruction.


lieutenant Finley, Of the Signal Corps,
recently described the known phenomena
of tornadoes, and the ends toward which
present researches are directed. These
storms have distinctly marked characters
tics, and are by no means to be COMPOUNDED
with hurricanes, billiards" cyclones or
northeasters. Their tracks are never more
than few hundred yards wide, and their
forces are generally exhausted by the time
they have Travelled course of forty or fifty
miles, though, in this latter respect, they
are quite variable, some having been traced
by their lines of devastation more than one
hundred and eighty miles. Their rotary
motion, which is greatest toward the CEN
ter, sometimes reaches the enormous rate
Of two thousand miles an hour, while their
forward movement, always from southwest
to northeast, ordinarily does not exceed
forty or fifty miles. They are usually un-
accompanied by electrical disturbances, and
are believed to be uninfuenced by electri-
cal conditions, though violent thunder
storms sometimes follow them few miles
away. There is a distinct and curious re-
lationship between the tornado and general
storm center, which is always apparent in
their uniform relative positions the torna-
do always occurring enthusiastically from
the center Of low barometric pressure, and
at a distance Of from one to six hundred
miles. The shape of the general storm
center, the direction in which its longest
diameter lies, and the appearance of the
upper and lower clouds, enter as minor
clements into the problem out of which the
weather experts hope to work complete
system of tornado warnings. The visits of
the tornado are commonly between the
hours Of two and six o'clock in the after
noon. It's home is an area which includes
the whole of Iowa, all Of Missouri, except
the southeastern corner, the northwestern
corner of Arkansas, the northeastern part
of the Indian Territory, Eastern Kansas,
Eastern Nebraska, Southern Minnesota,
Southern Wisconsin and Western Illinois.
Here its season extends from April to Au-
gust, inclusive 1t is frequent visitor to
two other regions One is strip along
the gulf and South Atlantic coasts, which
takes in the central portions Of Alabama,
in Mississippi and North Carolina, over
which its devastations are confined to the
months OF January, February and March.
The other includes portion of Southern
and Central Ohio, a large part of Pennsyl-
vania, a small area in Maryland, strip
across New York, and corner each of
Massachusetts, and Connecticut, where it is
in season only during the months of August
and September
The conditions which are favorable to
tornadoes are present when cool dry cur
rent of air meets warm moist current,
bringing wide extremes, both of tempera-
ture and humidity into close proximity.
The cool dry currents come from the north,
but such that flow over the great lakes pick
up in their course both moisture and heat,
and their destructive forces are thus neu-
tralized. Those blowing from the far
northwest down over the dry plains of
Manitoba and Dakota carry something of
their Arctic characteristics far south, and
if in their course they meet one of the heat
and vapor-laden breezes coming up from
the Gulf, the war of the elements begins at
the point of contact The storm always
has its birth in the upper air, its first visi-
bic manifestation being the ominous fun
nel-shaped cloud, whose pendant trunk is
in form not unlike that of an elephant.
Within it the furies are confined, and when
and where its point touches the earth the
path of destruction begins When the
isotherms of the morning signal map shows
the advancing columns of air, with their
wide contrasts of temperature, in proximi-
ty; when the general storm center is in that
relative position which seems necessary to
the exercise of its mysterious influence;
when the pressure is low toward the east,
disclosing vacuum, into which the defect
ed currents may advance without obstruc-
tion-when all these conditions combine,
it should become but simple problem for
the experts to determine with reasonable
probability from the wind velocities whether
the threatening line of contact will have
advanced to or beyond the tornado's ac-
customed haunts by the time of day when
the powers of mischief shall be loosed.