St. Tammany farmer. [volume] (Covington, La.) 1874-current, 1904-06-18
STORMS AND THEIR CAUSES
Interesting Facts Regarding the
Sources and Courses Of Atmos-
pheric Disturbances.

1 .+f zs 8 q tt . ( 81 q 4
| Few persons who grumble about tn
weather know. or, if knowing, stop 4
think that the storms which sweep owe
the country periodically are only tn
result OF the processes which Natur
has adopted to "ventilate'' the atmos
phere Of the earth and make the glob'
| habitable. Storms are simply win.
movements, and without them the at
mosphere surrounding the earth woule
become foul and stagnant. says TIN
Cleveland Leader.
Wind movements are the result o
varying air pressure, as measured b,
the barometer. High pressure is pro
duced by the condensation of dry, COLI
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. w 8
On the American continent there II
an air expander as we'll as an air con.
denser. The expander is located over
the equator, while the condenser is
found in the high plateaus of the Sas-
katchewan country, north of the Da.
kotas and Montana Air heated over
the equator and filled with moisture
there rises. and rolls northward toward
the pole. Near the thirtieth 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 flow
across the country which produces
winds that accompany storms. These
winds always blow toward the low
end are high or mild as the low"
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 2 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 rule,
and go out to sea over the gulf OF st.
Lawrence. Sometimes they go up the
Atlantic coast in the form of huFri-
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 il they take
that course in winter they are followed
by warm weather in the northern
states. as. s,s,,5 ~ sfssss s..,z5 ~
These storms of low area cross the
United States periodically. They aver
age eight month from May to August;
nine month from September to Mo-
vembers and tn April; IL month in
February. March and December; and
IL month in January. The average
velocity of these storms that is their
forward ACKNOWLEDGEMENTS. It is Is
miles an hour between June and Septem-
Der; 20 in October; 80 in November; 50
in December; 80 in January and Febru-
airy; 80 in March, and 26 in April. 5tS