Evening star. [volume] (Washington, D.C.) 1854-1972, 1882-02-25
Foretelltmx the Weather.


studied and recorded the weather. know best
that beyond two or 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 woful failures in guessing.
Everybody has full liberty to guess what the
weather will be at any time in the future. But
when anybody undertakes to label his guesses
for weeks or months ahead ''predictions,n and
to issue them as guides for the farmer, or the
traveller, or the clothing dealer he in the Ian
guage of Shakespeare, ''Writes himself down an
ass When he undertakes to get money for
doing this. he shows himself a sWndler ON q
level with 9th er 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 of doubt And not only can this
be done by the trained observer at the signal
station, but it may be attempted with good sue
cess by any Intelligent person who has access to
the daily weather maps, or even to the full daily
report. 1t would be great gain to the COM
munity 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 mate
dog-fghts, and police courts.
The Whole theory OF fOretelling changes In
IN.
based upon the fact that our weather changes
come, as general rule, from the west and not
from the east: that the great waves of barO-
metric pressure, which We name high and low,
and whose alterations produce our storms move
across our country from west to east and
almost never in the opposite direction SO that
Tor our weather tomorrow we look to see what
1t is to-day to the west of u.s. with very little
interest as to what is going on to the eastward.
mus In New England, northeast snOw-storm
is OFTEN teiegraphed as coming from the south
west, from New York. or even from Virginia
or the CarOlinas or even from farther SOUTH
The pressure of the atmosphere in the temper
ate zone varies about one pound per square
inch. and is Indicated by the barometer varying
from 20 inches QOw) to 81 inches (high) as the
extremes. the ordinary variations being only
about half as great. Now the stom-center isat or
near the place of low barometer where the
pressure is least. the air from all sides rushing
toward this with rotary motion, which IN
very severe storms is named a cyclone. Some
times, however, the areas of high and low ba-
rometer 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
sometimes from the lakes to the Gulf. The
greatest fall Of rain or snow is usually little
In advance OF the stOrm-center while the ba-
rometer is falling. When the center has PASSED
the barometer begins to rise. and clearing
weather may be expected, generally with north
west winds.
These stOrm-centers, or ''areas of low barome-
ter. OF Low pressure oftenest make their APP
pearance little east of the Rocky mountains
very often in Dakota, and then move with
greater or less raDldity toward the Atlantic,
generally due east. Occasionally a storm
center develops IN Texas and moves northeast
More rarely cyclones make their appearance in
the West Indies and follow along the course of
the Gulf stream, the outer edge sometimes
reaching the Atlantic coast, very rarely extend
ing inland.
Out Of 100 stOrm-centers noted during 1879,
one moved north. three southeast "a northeast,
and - nearly due east. Their velocity varies
from 70 to 20 miles per hour. 80 that either
stOrm-centers or cold waves travel from the
mountains TO the sea in from two to five days,
then passing off upon the ocean. frequently TAX
ing n0rthcastery direction after reaching the
coast. Sometimes storm may be detected
from It's course, or spend its force mid
way, or Increase in severity. as 1t moves
eastward. 1t is these possibilities. together
with the varying velocity of the wave. when
render Us dependent on the telegraph for its
record OF daily OF even hourly progress. and
which sometimes contradict tie best-GDtintled
predictions. But with all these possibilities of
error, 80 to 30 per cent OF the predictions are
verified. and upon perhaps IS per cent our re-
ance may be almost perfect. At times either
on land or sea, single warning NAV
save property to an amount greater than the
whole annual expense of the bureau to say
In general terms, comes from the west and
when we read in the papers that IAN area of
low pressure with heavy rain and severe gales is
developing in the upper Mississippi. or upper
lane REGION" the farmer had better
not begin his hay or his harvest
ing. and the Traveller had better not
set ont by way of the lakes or the ocean until it
has passed by. While if in the fall or winter
you read that IAN area of high pressure with
violent winds and rapidly falling temperature is
prevailing In the same regions. the farmer had
better look to his young stock and make all
snug about cellar and barn. and the traveller
will do we'll to take his heaviest oyercoat
Bearing in mind these few simple facts. every
farmers boy who has access to the daily ''indica-
lions and reports" or better still! to the daily
weather maps, may become. to great extent,
his own weather prophet for two or three days
ahead, aud thus neither be taken in by the
guesses Of those who make predictions to sell.
nor fail Of advantage which may often be gained
by toleraby definite and reliable knowledge Of
what Ort of weather is coming