The Indianapolis journal. [volume] (Indianapolis [Ind.]) 1867-1904, 1902-01-28

was not an over abundance OF gas made IL
seem all the colder. At o'clock last night
the announcement made at the
Weather Bureau that the thermometer
would probably go from to 10 degrees be-
low zero before morning.
ORIGIN OF COLD WAVES.
To the average person a cold wave mere
ly means a cold snap which strikes the
section of the country he lives in. remains
a few days and then moves on. People
do not commonly understand that this
wave is composed of various air currents
which combine to create IT, and that IL has
a distinct origin and termination. Very
often in the weather predictions one reads
that a cold wave is coming from a dis
tant section of the country along a we'll
defined route, but how this wave is formed
or what are its sources he knows little or
nothing about Only those who des6Is
their entire time TO the weather. as. for in
stance, the men connected with the United
States weather service. really comprehend
the cold wave. w. 7. Blythe. who is at
the head of the local Weather Bureau.
in talking TO a Journal reporter on the SUBJ
ject of cold waves, said:
Il may say, briefly, that cold waves orig
mate in the British Northwest Territory:
or. TO be little more exact, about IS per
cent. of them originate on the eastern
slope OF the Rocky mountains in the Ca
madam possessions and about Is per cent.
are first felt in the United States on the
Pacific coast.
''As TO the origin of cold waves IL can
not be so easily determined, IL involves
a discussion OF the great problem OF air
circulations. What we call lows that is,
atmospheric eddies. frequently designated
by the Weather Bureau storm centers,
centers of depression and cyclonic areas
or cyclones. and higher or anti-cyclonic
fVV1FnC fFh
reau charts indicate the center of areas
covered by greater barometric pressure.
at times during the late autumn, winter
and early spring, are preceded and ac-
companied by such marked and rapid falls
in temperature as to be called cold waves"
WEATHER BUREAU BULLETIN
At this juncture Mr.. Blythe took from
his book shelves Weather Bulletin No ia.
1886, which was compiled by Professor
Frank H. Bigelow. from which he read:
ION the eastern slope of the Rocky noun
tains in the Canadian possessions. in the
neighborhood of lis degrees west longitude
and 50 degrees north latitude. there ex-
lists a peculiar mechanism whose work
is TO turn out a series Of highs and lows
following each other in apparently for
tuitiOus sequence which then advance over
the United States This Northwest
region is of especial interest I'm the meteor
ology of the United States, for IL is prac-
ticallN the heaft OF the ClrculdUOnS or air
that passes eastward. and, II IL is possible
10 fully understand the action OF the forces
operating there. IL will become much easier
TO generalize safely concerning many other
problems I'm the physics OF the atmosphere.
The leading feature In the meteor
ology of the earth is the fact that the
suns radiation warns the tropical and
temperate zones, leaving the arctic regions
cold. From this unequal temperature there
are produced CONGREGATIONAL currents. OF
which the primary are the tropical trades
blowing westerly AMI the current in
the temperate zones blowing easterly.
Recommending on this subject I'm 1900 Pro-
fessOr Willis L. Moore, chief Of the United
States Weather Bureau. says: Our storms
simply great eddies in the air that
are carried along BY the generally easterly
movement Of the atmosphere In the middle
latitudes Of the northern hemisphere.
The highs are attended by dry, clear and
cooler weather and by vertical action or
their centers. They are drawing down the
cold air from great attitudes above the
clouds df any and causing IL To flow away
laterally along the surface OF the earth in
all directions from the center Although
these intense high pressure areas first ap-
pear I'm the extreme Northwest. they do not
depend upon the land OF their birth for the
cold that they bring 10 us. They are not
simply immense rivers Of air that have
been chilled by flowing over the great snow
and ice fields OF the arctic region. was
once thought.
TERMINATION OF COLD WAVES.
Where do cold waves terminate and
what causes their determination? Mr..
Blythe asked.
TO make answer 10 this question inteili-
gently IL Is necessary 10 revert TO the fact
that highs and lows drift across the
try from west 10 east successfully. that
while the highs are invariably preceded or
accompanied by cooler weather. only a conI-
paratively few are attended by such
marked rapid falls In temperature as 20
warrant the change being called a cold
wave and 70 explain that for forecast pur-
poses I'm connection with cold waves the
country east Of the Rocky mountains IL
divided into districts according 20 the rela-
tive frequency and intensity Of the waves.
The region most marked In this respect
embOdes the Northwestern States. and
that least marked includes Florida and the
gulf coast. The temperature falls required
10 verify a cold-wave forecast vary with
the district and the season OF the year. In
the district which includes Indiana a fail
OF - degrees 10 a temperature OF 10 de-
grees. lower In twenty-fOur hours Is re-
Quirod 20 verify a cold wave during the
month1fof December. January and Febrsl-
airy Inclusive During the remainder or the
year. from March 10 November. a twenty
four hours fall OF 20 degrees 10 a tempera-