Juniata sentinel and Republican. [volume] (Mifflintown, Juniata County, Pa.) 1873-1955, 1882-06-21
Storm Scrence.

/ All atmospheric cOndltlOnS. anu no.
tably storms, are controlled by unvary-
ing laws thst are easily comprehended
and susceptible of application by any
intelligent observer, who, noting the
conditions that exist, may reason there
] from to the conditions that must ensue
In other words, by understanding the
laws Of meteorology and considering the
observations daily reported in the news
papers, one may make his own forecasts
the value of which will depend only ON
the carefulness of his predictions. 1t
must be understood, in the first place,
that storm is not of local origin. For
instance, a storm does not form at one
point at the same time another is form
ing at Cairo, Omaha, Buffalo or Duluth.
This Is a popular error. and the cause
CT mfny delusions. On the contrary,
ninety-nire out of every hundred storms
In the United States originate on the
arid plains east of the Rocky Mountains,
and from there move eastward. The
process of the origin of q storm, now
well understood, consists of the forma-
ton of ''storm CENTER" or area of low
barometer, terms which are practically
synonomous.
The atmosphere is n varying depos-
itory of sun-heat acquired directly from
the suns rays and fiom the heated sur
face of the earth. On the barren and sandy
plains this acquisition of heat is aug
mented by the more powerful reflection
of the sand, and presently a body of ar,
many miles in circumference, will be-
come super-eharged with heat, which
induces a greater absorption of moisture
from the earth's surface and surround
ing atmosphere. This heated body of
air, true 10 that law which causes the
lighter heated atmosphere 10 ascend
(nowhere better demonstrated than at
the ordinary chimney commences to
rise; other air rushes in below, which,
encountering the same heating surface
Is i'll turn heated, rises, ard gives place
continuously to other air. This is a
storm center and the country over
which this operation is going is an area
of low barometer (and high thermom-
eter,) called so from the fact that the
atmosphere. having an ascensive mo-
ton, counteracts In measure Its down.
ward pressure, and for other minor rea-
Sons not necessary to detail. This ris-
ing body of air, highly charged with va
por (another name for moisture) ascends
until it passes the dew-point, which Is
the point where the moisture III the at
mosphere viii begin to resolve itself
again into water and descend in rain
This operation of the condensation of
moisture from vapor is noticeable on the
outside of pitcher Of ice-water, on the
water-pipes in houses, or on any metallic
surface in a damp house where there Is
no fire.
The ascending body of atmosphere at
each point of its ascent encounters col
der AIR, and the latent heat, released by
the condensation of vapor augmenting
its temperature, its progress upward Is
increased instead of diminished, until
finally reaching the higher strata of air,
it spreads outward, on top as it were,
piling up, if the expression may be used
and so deepening at the circumference
of the storm, which, together with the
fact that the atmosphere has a slightly
onward motion at the same point, creates
a circle of high barometer, or great air
pressure outside the storm.
The operation of condensation of
moisture manifests itself to the eye by
the formation of clouds which is an in
termediate stage between vapor and
water, and which, with the significance
of their varied formations in relation to
future weather, will be treated below.
The atmospheric disturbance outlined
is storm, and no sooner is 1t formed
than it begins to move eastward. All
well-desloptedstorms in the United States
move from west to east, DETECTING
slightly to the north. This northward
direction is more noticeable III winter,
almost disappearing in summer. Occa-
sionaliy storms depart from their east
ward course and move directly north,
but as these are freaks, and Ofrare occur
renee, they cannot be said to be more
than equivalent to railway train get
ting off the track owing to some unna-
tural condition of, or obstruction on, the
track, and can rarely be predicted, but
must be taken into consideration as
possible contingencies, Storms vary IN
circumference and shape. In Europe
they are more nearly round than in
America, where they are of more
irregular, oval form. In size they vary
from diameter of few miles to those
that reach from the Gulf to beyond the
lakes.