Ellsworth American. [volume] (Ellsworth, Me.) 1855-current, 1914-02-18
WEATHER FORECASTING.
How the Weather Bureau Predicts
Storms, Frosts and Floods.

How the Weather Bureau Predicts
Storms, Frosts and Floods.
Many people have an idea that there is
something mysterious and occult about
the work of the weather bureau in fore
casting the coming of storms, frosts and
floods. Not few think that the obser-
reading the planets, the stars and the
moon. As matter of fact, the forecaster
of the bureau foretells the coming OF dis
turbances in a business-like way, very
similar to that in which man who has
ordered shipment of goods would esti-
mate the date OF its arrival.
Suppose a business man had ordered
Islands. He would know the average
time it would take the steamer to make
the trip to the Pacific port, the average
time for unloading 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
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 Philippines,
Japan, Siberia, Alaska, Canada or the Gulf
of Mexico. The weather bureau gets
able, telegraphic or wireless notice OF
foreign storm. Station after station, or
vessel after vessel reports the storms ar
rival in its neigh borhood, so that the gen.
eral direction and rate of progress can be
determined very early. In fact, the ar
rival Of some storms can be foretold ten
days in advance.
The forecasters watch for the region of
low barometer, which is the storm center
around which the winds blow. This whirl
or eddy moves bodily forward with the
general eastward drift OF about $50 miles
day in our ATTITUDES. AS the lines of
equal pressure Qsobars) around the low
center crowd closer together, the winds
attending the storm increase in force.
The forecaster determines the direction of
movement of the storm and its velocity.
When weather distur Dances are reported
the forecasters know from experience
about how long it takes them to reach our
Pacific coast, and then how long after
they will reach the Atlantic coast. !
For example, If a storm coming from
Siberia drifts eastward around the North
Pole and reappears in Alaska, it should
appear in Washington and Oregon in
about two days; should get to the Great
Lakes in six days and to the Atlantic
coast in seven or eight days.
Unexpected conditions NAV DELAY
storms or divert them from the straight
track just as a refrigerator car NAV be
thrown off its schedule or be shipped by
accident on wrong road. Some of these
storms deplete themselves by running
into regions of high barometer which are
OF greater magnitude and extent than the
storm itself. Some of them, however.
travel completely around the world
To keepstab on cold waves that come
into the United States from Canada and
Alaska, the weather bureau studies the
Canadian weather reports. England
sends reports from Iceland, the British
Islands and continental Europe, and daily
reports come from St. Petersburg on the
conditions in Russia and Siberia.
The same business-like system used in
tracing the track of storm is applied in
determining the arrival of frosts.
Flood forecasts are made in much the
same way. Information as to the amount
OF rainfall at the head waters of streams
that cause floods are covered by tele-
graphic reports sent by local observers.
AS this rain reaches the main channel. the
height OF the water in the channel is de-
termined by successive gauging stations.
Past records established how much a
height, say of twenty feet at DUBUQUE.
Iowa, Will produce at Davenport, another
station eighty miles down the Mississippi.
This plan is followed all the way down
the river, and at each point full allowance
Is made for the effects of water from trib-
utaries, and from additional and local
rainfall. As result of these observations
In the recent food, the people Of Cairo had
warning week or ten days in advance.
Inc Pittsburgh district can be given only
twelve to twenty four hours notice. be-
causela flood is upon them within twenty.
four hours after a heavy rs;n e+orr