The Bossier banner. [volume] (Bellevue, Bossier Parish, La.) 1859-1952, 1882-06-22
How to Foretell the Weather.

How to Foretell the Weather. ~,
Those who have longest and mos,
carefully studied and recorded the
weather know best that beyond two OF
three days no predictions can be made
possessing the slightest reliability, or
that should be taken into account in
making our plans. There may be lucky
guesses, as there may be woeful failures
in guessing. sd
Everybody has full liberty to guess
what the weather will be at any time in
the future. But when anybody under
takes to label his guesses for weeks or
months ahead !" predictions and to
issue them as guides for the farmer, or
the Traveller, or the clothing dealer,
he, in the language of Shakespeare,
''writes himself down an ass" When
he underta kes to get money for doing
this he shows himself swindler on a
level with other quacks.
But for one or two, or even three DAYS
ahead the weather may be foretold two
thirds of the time with great certainty:
the other third with more or less doubt.
And not only can this be done by the
trained observer at the signal station,
BUTT may be attempted withgood sue
cess by any intelligent person who has
access to the daily weather maps or even
to the full daily report. It would be a
great gain to the community if our daily
papers would give us these reports in full
as they are sent out, instead of cutting
them down to mere Indications for
their own vicinity, even if they had to
lessen the space given to horse-races,
baseball matches. dog-fights and police
courts.
The whole theory of foretellino
changes in the weather with the. aid Of
thetelegraph is based upon the fact that
our weather changes come, as q general
rule. from the west and not from the
east; that the great waves of barometric
Pressures which we name high andslow,l
and whose alterations produce our
storms, move across our country from
west to east, and almost never in the
opposite direction, so that for our wealth..
er tomorrow we look to see what it is
to-day to the west OF US, with very little
interest as to what is going on to the.
eastward. Thus in New England q
northeast snow-storm is often telegraph
ed as coming from the southwest from
New York. or even from Virginia or the
caroiinas, or even from farther South.
The pressure of the atmosphere in the
temperate zone varies about one pound
per square inch, and is indicated bv the
barometer, varying from twentY-nine
inches Cow to thirty-one inches 1hieh)
as the extremes, the ordinary variations
being only about half as great, Now the
storm-center is at or near the place of
low barometer, where the pressure is
least, the air from all sides rushing to-
ward this with rotary motion. which
N very severe storms is named cyclone
Sometlnes, however, the areas Rof high
and low barometer extend in long lines,
across the country from north to south.
but moving from west to east, as in MANY
of our "cold waves" extending some
times from the lakes to the Gulf. The
greatest fall of rain or snow is usually
little in advance of the stornlcenfer.
while the barometer is falling. When 4
the center has passed the barometer be-
gins to rise, and clearing weather NAV.
be expected, generally with northwest
winds.
These storm centers, or ssareas of low
barometer, or Glow PRESSURE oftenest
make their appearance a littleeast OF. the
Rocky Mountains, very often i in Dakota.
and then move with greater or less
rapidity towards the Atlantic, generally
due east. Occasionally storm-centre
develops in Texas and moves northeast.
More rarely cyclones make their appear
ance in the West Indies and follow alonp
the course of the Gulf Stream, the outer
edge sometimes reaching the Atlantic
coast, very rarely extending inland.
Out OF LOO storm centers noted during
1879, one moved north, three southeast.
twenty-four northeast, and seventy-two
nearly due east. Their velocity varies
from twenty to forty miles per hour. SO
that either storm centers or cold waves
travel from the mountains to the sea in
from two to five days, then passing of
upon the ocean, frequently. taking a.
northeasterly direction after reaching
The coast. Sometimes storm may be
detected from its course, or spend its
force midway, or increase in severity as |
It moves eastward. 1t is these possibili- 1
aes, together with the varying velocity |
Of the wave, which render us dependent /
on the telegraph for its record of daily
Or even hourly progress. and which some |
Times contradict the best-founded predic-
lions. But with all these possibilities Of |
error, eighty to ninety per cent. ofsthe /
predictions are verified, and upon per-
maps seyenty-five per cent. our reliance |
may be almost perfect. At times. either
On land or sea, awarning may save prom /
srty to an amount greater than the whole
annual expense of the bureau, to say notIf- /
ng OF life and comfort. Our weather. I
hen, in general terms, comes from the +
vest, and when we read in the papers
hat '4an area of low pressure with heavy /
ain and severe galesis developing in the
upper Mississippi or Upper Lake region,p I
he farmer had better not begin his hay
ng or his harvesting, and the traveller
lad better not set out by way of the lakes
n the ocean until it has passed BY. While /
I IN the fail or winter you read that ian
lrea OF high pressure with violent winds
md rapidly falling temperature is pre-
in the same regions, y the farmer
lad better look to his young stock and
make all snug about cellar and barn, and I