Rock Island Argus. (Rock Island, Ill.) 1893-1920, 1914-01-22
NOTHING OCCULT
IN FORECASTINC
How Weather Bureau Learns
About Impending Storms,
Frosts and Floods.

Washington, ID. c., Jan. 22.-Many
people have an idea that there is
something mysterious and occult about
the work of the weather bureau in
forecasting the coming of storms,
frosts and floods. Not a few think
that the observers must necessarily
get their data by reading the planets,
the stars and the moon. AS a matter
of fact the forecaster of the bureau
foretells the coming of disturbances
that in which a man who has ordered
shipment of goods would estimate
the date of its arrival.
Suppose a business man had order
ed a carload of pineapples from the
Hawaiian islands. He would know
the average time it would take the
steamer to make the trip to the Pa
cific port, the average time for un-
loading and loading into refrigerator
cars and the average number of days
to be allowed these cars for their trip
across the continent to New York. His
estimate. however, would be subject
to error because the steamship might
be delayed by fog, or the cars might
meet with an accident.
Storms, like pineapples, as a rule do
not originate in the United States.
They come to us, some from the Phil
ippines. Japan, Siberia, Alaska, Can
ada or the Gulf of Mexico. The wealth
er bureau gets cable, telegraphic or
wireless notice of foreign storm.
Station after station, or vessel after
vessel reports the storms arrival in
it's neighborhood, so that the general
direction and rate of progress can be
determined very early. In fact, the
arrival of some storms can be fore
told ten days in advance.
The forecasters watch for the re-
gion of low barometer which is the
storm center around which the winds
blow This whirl or eddy moves bod
lily forward with the general eastward
drift of about $50 miles day in our
latitudes. As the lines of equal pres
sure Gsobars) around the low center
crowd closer together. the winds at
tending the storm increase in force.
The forecaster determines the direc
ton of movement of the storm and its
velocity.
When weather disturbances are re-
ported, the forecasters know from ex-
perience about how long it takes them
to reach our Pacific coast, and then
how long after they will reach the At
lantic coast For example, if a storm
coming from Siberia drifts eastward
around the north pole and reappears
in. Alaska, 1t should appear in Wash
ington and Oregon in about two days;
should get to the Great Lakes in six
DAYS and to the Atlantic coast in sew
en- or eight days.
Unexpected conditions may delay
storms or divert them from the
straight track just as refrigerator
car may be thown off it's schedule or
be shipped by accident on wrong |
road Some of these storms deplete I
by running into regions of |
high barometer which are of greater |
and extent than the storm
itself Some of them, however, travel |
around the world.
To keep tab on cold waves that
come into the United States from Can
ida and Alaska, the weather bureau
studies the Canadian weather reports.
England sends reports from Iceland,
he British islands and continental
Europe. and daily reports come from
st. Petersburg on the conditions in
Russia and Siberia.
The same businesslike system used
n tracing the track of a storm is ap-
lied in determining the arrival of
rosts.
Flood forecasts are made in much
he same way. Informa. ion as to the
mount of rainfall at the head waters
f streams that causes floods are COW
red by telegraphic reports sent by
peal observers. AS this rain reaches
he main channel, the height of the ,
Tater in the channel is determined by
uccessive guaging stations. Past rec ,
rds establish how much a height, say !
20 feet at Dubuque, Iowa, will pro- ,
uce at Davenport, another station so :
lilies down the Mississippi. This plan !
followed all the way down the river :
nd at each point full allowance is :
ade for the effects of water from ;
obituaries and from additional and
'cal rainfall AS a result of these 7
observations in the recent flood, the ;.
eople of Cairo had warning a week :
: ten days in advance. The Pittsburgh
strict can be given only Il to "a T
ours notice, because a flood is upon !,
lem within "a hours after a heavy .
lin storm.