Elmore bulletin. [volume] (Rocky Bar, Idaho) 1889-1906, 1896-06-03

WHYTHE MONTH or MARCH rs OFTEN
CLUSTERING AND STORMY.
Some Facts About Weather Changes Cold
Currents From the North and Warm
Ones From the South Efrects of Mag

netic Force.
March impresses itself upon the dwell
er III the rorthern half of the United
States as "A particularly windy and dis
agreeable month, with strong alterna.
lions of wintry and mild weather. This
is due to the breaking up Of the condi-
tons that have prevailed since Decem-
Der and the processes Of return to spring
and summer. There is in the arctic zone
an enormous amount Of cold material to
be disposed of, covering the northern
regions in the foym of ice and snow. At
the same time the southern zone is be-
coming decidedly warmer in conse.
quence of the advance Of the sun to the
northern side of the equator
The United States is peculiarly the
theater of this contest between the
giants of cold and heat, and they stag.
ger back and forth over this territory rs
one or the other is for the time being in
the strongest form. The cold waves
launch themselves from the north and
carry their icy chill to the warm south.
ern states; or, on the other hand. the
warm currents of air from the south ad
vance far into the north, and this alter.
nation causes rapid variation in the
temperature and the other weather con.
ditions at stations OF the middle lati-
tudes
An examination of the storm tracks
for March gives very definite evidence
OF the effect of this struggle for suprem-
acy.' Instead of being confined to the
neighborhoud of the mean tracks. it is
found that they spread ont over the en-
tire territory of the United States from
north so south. The phenomenon of
looping southwark along the Rocky
mountain slope before recurring north
eastward to the gulf of st. Lawrence 10
most pronounced.
The storms which first develop in AL
berta or ON the north Pacific. coast may
advance directly eastward over the lakes
to the gulf, or they may be pushed south
and recurve in Colorado, Missouri, south
efn Illinois or southern Indiana, in or
der to move to the St. Lawrence val
ley, or else they may be propelled still
farther south along the Rocky mountain
slope to Texas and the gulf coast, whence
they proceed to the south Atlantic coast,
and then turn northward to Newfound-
land. Not a few of these storms dissi-
pate in the lake region or the Ohio val
ley; others will persist in path of
nearly 5000 miles, from Alberta to
southern Texas, South Carolina and
finally to Newfoundland. The unequal
distribution Of the tracks of the storms
in March is therefore due to the irregu-
lar propulsion of cold masses of air from
the arctic regions into the middle of the
North American continent.
A popularity of continental action is
that in summer the interior is warmer
than the borders, but in winter the in
terror is colder than the coasts. The up
per lake region and the upper Mississip-
pi valley are especially remarkable for
this feature. Between the 80 degree and
100 degree meridians, and between par
allels so degrees to 55 degrees, the
change in temperature is the greatest
known i'll North America: it is coolest in
winter there, and also it may become
the hottest part of the country in sum-
mer; the range of temperature may be
from As degrees below zero in winter to
l05 degrees above zero in summer,
range of 15o degrees. The encroach-
ments of spring upon the winter in
North America proceed from the ex-
treme southwest, the gulf of California
and the Colorado river valley, and adj
vance toward the northeast.
This leads to description of one of
the most characteristic features of the
advance of the summer upon the North
American continent. In winter the lines
of equal normal temperature, that is. !
the isotherms, are grouped about the
cold pole in quite symmetrical mau
ner, bending southwark i'll the interior
as they pass from the Atlantic to The
Pacific coast. This confguration may be
regarded as normal from November to
March inclusive III the summer the
formation is somewhat inverted. the
lines bending northward from the coasts
toward the interior, though the crest is
now farther west i'll the dry Rocky
mountain region. The pnlf of Califor-
mia is the central region Of heat, and
the crest extends from Yuma A. T.,
northeastward toward the Dakotas.
The magnetic force seems to be eff |
eient in producing meteorologi effects
in proportion as it can operate in cold /
conditions. Hence the en- |
croachment Of warm air from the south
ern Rocky mountain districts, as spring I
comes on is unfavorable for this kind /
of action, and it seeks to transfer its l
seat TO the portions of the interior of
the continent that still retain low tenn
peratnres, namely. to the Hudson bay
districts. Finally MS the summer heat
this cold territory, the winter
high passes away entirely, and the
whole arctic region is covered by low
pressures.
The unsettled weather of the month
of March, especially i'll the northeastern
portions of the United States, with its
rapid alterations of warm and cold
winds, often reaching considerable vio-
lence. is, therefore, the parting salute
Of the cold winter that has prevailed
for five months throughout the northern
cap. most impressive feature of this
change, as deduced from close study
Of the barometers and temperature read
ings of the weather bureau. is the sud
denness with which the struggle is CON
cluded in the northwest, for March of
ten comes in with very violent action.
and this is almost certain to end about
the goth of the month with moderate