Warren sheaf. [volume] (Warren, Marshall County, Minn.) 1880-current, 1914-01-28
HOW THE WEATHER BUREAU
Il FORECASTS STORMS, FRosTs
AND FLOODS.

Washington, D. c., Jan. % Many
people have an idea that there is
something mysterious and occult
about the work of the Weather Bu-
reau 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 in a business like way,
! very similar to that in which man
who has ordered shipment of goods
would estimate the date of its arri-
wal
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 I'M
| 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 steam
ship might be delayed by fog, or the
cars might meet with an accident.
Storms, like pineapples, as 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
weather bureau gets cable, telegra-
phic or wireless notice of foreign
storm. Station after station, or YES
| sci after vessel reports the storms
arrival in its neighborhood, so that
the general direction and rate of pro-
1 gress can be determined very early.
| In fact, the arrival of some storms
can be foretold 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 east
1 ward drift of about $50 miles day
4 in our ATTITUDES AS the lines of
4 edual pressure (isobars) around the
4 low center crowd closer together, the
1 winds attending the storm increase
! in force. The forecaster determines
/ the direction 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 the Atlantic coast. For
4 example, if a storm coming from ST.
IBERIA 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 may delay
storms or divert them from the.
straight track just as refrigerator
car may be thrown off it's schedule
or be shipped by accident on a wrong
road. Some of these storms deplete
themselves by running into regions
of high barometer which are of great
er magnitude and extent 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
reau studies the Canadian weather
Iceland, the British Islands and Con-
tinental Europe, and daily reports
come from St. Petersburg on the con-
| ut''iuS III ItuSSld ctuu OlUCIld
The same businesslike system used
in tracing the track of storm is ap-
piled in determining the arrival of
| frOsts.
| Flood forecasts are made in much
| the same way. Information as to
the amount of rainfall at the headwa-
tiers Of streams that cause floods are
covered by telegraphic reports sent
by local observers. AS this rain
reaches the main channel, the height
of the water in the channel is deter
mined by successive gaging stations.
Past records establish how much a
| height, say of 20 feet at Dubuque, To-
wa, will produce at Davenport, an
other station 80 miles down the Mis-
sisippi. 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 local rainfall AS
a result of these observations in the
recent flood, the people of Cairo had
warning a week or ten days in ad-
vance. The Pittsburg district can
/ be given only II to "a hours notice,
because flood is upon them within
"a hours after a heavy rain storm
l D,e$or Doei1nc z