Williston graphic. (Williston, Williams County, N.D.) 1895-1919, 1904-06-23
STORMS AND THEIR CAUSES
Interesting Facts Regarding the
Sources and Courses Of Atmos-
# rpheric Disturbances.

Few persons who grumble about thu
weather know, or, if Knowing, stop tt
think that the storms which sweep oye1
the country periodically are only thu
result Of the processes which Nature
has adopted to "ventilate" the atmos.
phere OF the earth and make the globe
habitable. Storms are simply wine
movements. and without them the at
mosphere surrounding the earth woul(
become foul and stagnant, says the
Cleveland Leader.
Wind movements are the result Of
varying air pressure, as measured by
the barometer. High pressure is pro.
duced by the condensation of dry, cold
air, and is followed by the precipitation
of atmospheric currents from high al.
titudes toward the earth. Low pressure
comes from the heating of the lower
air strata, and the absorption of moist.
ure, and is followed by rising currents
of air.
On the American continent there is
an air expander as well as an air con-
denser The expander is located over
the equator, while the condenser is
found in the high plateaus of the 6as-
katchewan country, north of thu Da-
kotas and Montana. Air heated over
the equator and filed with moisture
there rises and rolls northward toward
the pole. Near the thirtfeth degree
north latitude it drops toward the earth
and encounters the masses of dense,
dry air, which are continually being
piled up about the polar region.
1t is the continuing conflict between
the low pressure and the high pressure
which produces the storms. Each storm
has center, and that is the point at
which the atmospheric pressure is low
est. The storm center is called the
"low" and it is the progress of the 'low''
across the country which produces
winds that accompany storms. These
winds always blow toward the Glow"
and are high or mild as the Glow"
varies in intensity.
Many of the storms which sweep
across the United States originate in
the Caribbean sea or the gulf of Mex
leo, but a large proportion Of them
start in Montana or across the Cana
dian border. Storms of equatorial or
igin, if they strike the land, follow the
Mississippi and Ohio valleys, as a rule,
and go out to sea over the gulf Of st.
Lawrence Sometimes they 60 up the
Atlantic coast in the form Of hurri
canes, causing north or northwest
winds over the greatest part of the
United States east of the Mississippi.
The storms which originate on the
plateaus of the Rocky mountains are
milder than those that come from the
gulf of Mexico. Sometimes they swing
around over the middle states, but
more frequently cut across Canada
north Of the lakes, and If they take
that course in winter they are followed
by warm weather in the northern
states.
Thesesstorms Of low area, cross the
United States periodically, They aver
age eight month from May to August;
nine a month from September to No.
vember and in April; II month In
February, March and December; and
IL a month in January. The average
velocity of these storms-that is their
forward movement-varies. 1t Is 70
miles an hour between June and Septem-
Der; 20 in October; 80 in November; 81
in December; 80 in January and Febru-
ary; 80 in March, and 26 in April.