The Maryville times. (Maryville, Tenn.) 1884-1944, 1886-02-17
ooip Waves.

- Hb~8so - VAee8S
HSA1s = = IeSe rspesrasu 3
The results q : rsliminAsyse6 al
"Cold Waves "a llsly m l 4 by
First Lieutenant Thornas -. ~ uff,
Fifth infantry, acting dgnal ~ has
been issued In the series Il dgnal.ser-
vice notes. "Cold waves" are defined
rs changes from higher TO lower
temperature, which seem to b lido.
pendent Of the time of day and a. tho
season Of the year and have an sxssnd-
cd progressive movement across tie
couAtry.
lnvanous investig atoms and studies
Lieutenant Woodruff says: 1t has been
shown that a fall of temperature sue.
ceeds or follows an area of law barom.
eter. and . rise precedes such an area:
and that in general the reverse is true
of an area of high barometer, viz: that
a fall precedes and a rise follows it.
We should then. perhaps, have these
questions asked: Is the cold the effect
Of an area Of high barometer, or is the
areaef high barometer due to decrease
Of tenpefatureP The solution of these
questions would, the writer says, make
the study quite simple and give very
safe way Of predicting cold waves, Not
answering these questions, but accept
ing,the two general conclusions above
given, Lieutenant Woodruff passes to
the facts presented upon the tri-daily
temperature charts Of the United States
signal service for the years 1881. 1882,
1888 and 1884, and the months of JAM
uary June inclusive.
! In .arious studios upon the origin
and movements Of areas of high and
low barometer, the Lieutenant says it
haa been shown generally that they
move almost invariably across the
United States from west to east. The
determination OF the movement of the
barometer largely determines the move
unent of the following high. Now most
Of the areas of low barometer are
formed in the region of the Rocky
Mountains, and rs these areas move
eastwardly the high moves in, and we
have accompanying cold wave Of
more or less intensity. Even if the low
area pursue an abnormal track the cir
culation of the winds about the high
and low is such as to produce almost
invariably decided fall in tempera.
ture, if the low be eastward of the high.
An inspection of the charts referred to
shows that during the months named
there were twenty-one cold waves in
1881, twenty in 1882, twenty-six in 1883
and twenty-one in 1884. The cold
waves are most frequent in the first
three months of each year, and the
month of January has more than any
month. No cold wave Is noted in this
enumeration unless it produced an alb.
normal change Of fifteen degrees OF
more in its passage over the selected
stations which were as follows Helena,
Mont; Bismarck, d. T.; st. Paul.
Mimi; Omaha, Neb.; Chicago, III.
st. Louis, Mo-; Shreveport La; Gal
weston. Tex. Nashville, Tenn; Buffalo.
NY; New Orleans, La; Jacksonville.
Fla; Boston, Mass. and Washington,
u. G.
ADAbout fifteen per cent. o: the cold
~es'Uhserved come from the Pacific
coast and .eighty.five per cent. origi.
mated east,of the Rocky mountains. OF
came down the east side OF these mount.
aims from the British Northwest Terri.
tory. All of the cold waves traced on,
during these six months in each year
appeared first at Helena, Mont, except
i've, which five were felt at Bismarck
d. T., before being felt at Helena; and
We must conclude says Lieutenant
Woodruff, that they have their origin
in the vast regions Of ice and snow
near the Arctic circle, far to the nortt
Of the observing stations. With re
spect to the time Of day of the appear
ance Of cold waves in the Northwest
1t is found that there is no absolute rule
and that they are quite Independent
Of the diurnal changes of Temperature
due to the alienation of day and night
Forty made their first appearance upor
the three p. nj. washington time)
temperature charts, which in the North
west corresponds to about the warmes
part Of the day, and ten first appeared
upon the eleven p. m. charts.
In respect to their progressive mo
ton, Lieutenant Woodruff divides colo
waves into three classes. Of tn
lightweight observed twenty-five be
longed to the first class or to those tina
move directly across the country from
west to east, and which follow an al
most invariable path along the chair
of great lakes and across New Englan,
| and do not extend to the States soutl
Of the Ohio river. To the second elias
! those which move in southeastern,
direction and cover the entire cOuntr,
in their progress-he assigns forty
seven out Of the eighty-eight and he as
signs nineteen to the third class-thos
which move southerly from Montan
and Dakota to Texas, thsncej through
the Gulf States, and then southeastern
over the Atlantic coast States. i
sometimes occurs with the third elias
that the cold wave Is first felt at 81
Louis and Shreveport before being fel
at st. Paul and Chicago, and that tbel
the cold wave takes the general hQYe
ment eastward Of the sseend class.
In commenting upon results and In
6uenceS\ of .ce4d waves, Lieutensn
Woodruffsats: 1t often happens that
cold wave lets in from the extrem
Northwest, and upon reaching tn
1