The Republican journal., 1914-02-05
The Weaker Bureau.
How II Forecast. storms, Frosts and Flood.

l 49,
How II Forecasts Storms, Frosts and Floods.
WASHINGTON, D. c., Feb. 2, 1914.
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 OBJ
servers must necessarily get their data
by reading the planets. the stars and
the moon. As matter of fact the fore
caster of the Bureau foretells the coming
of disturbances in businesslike way.
very similsr to that in which q man who
has ordered shipment of goods would
estimate the date of its arrival
Suppose business man had ordered a
carload of pineapples from the Ha-
waiian 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
nun Der 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 steam
ship 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 cable, Geographic or wireless no.
tice of foreign storm. Station after
station, or vessel after vessel reports
the storms arrival in its neighborhood,
SO that the general direction and rate of
progress can be determined very early.
In fact the arrival 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 a day in our latitudes. As the
lines of equal pressure Gsobars) 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 disturbances are report
ence 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 At
lantic coast in seven or eight days.
Unexpected conditions may delay
storms or divert them from the straight
track just as a refrigerator car may be
thrown off its schedule or be shipped by
accident on wrong road. Some of
these storms deplete themselves by rum
ming into regions of high barometer
which are of greater magnitude and ex-
tent than the storm itself. Some of
them, however, travel completely around
the world.
To keep tab 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 ard 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 a 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 headwaters 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
determined by successive gaging sta
lions. Past records establish how much
height, say of 20 feet at Dubuque,
Iowa, will produce at Davenport, anoth-
er station 80 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
tributaries, and from additional and To-
cal rainfall. As result of these obser-
vations in the recent flood, the people of
Cairo had warning week or ten days in
advance. The Pittsburg district can be
given only IL to "a hours notice, because
a food is upon them within "a hours
after heavy rain storm