The sun., 1888-02-12
THE sWEnr OF THE COLD WAVE
sene Resuits ef efObservatiess Csneernins the
Career OF the Grea Aueriean BiisssrA.

Some Results sf Observation Cencern,nr the
Career OF the Great Arerican Bnss.rS.
Prom the st Puu, rsor,er P,~ss
As In the case OF the tornado. the direct
1t Is known that a majority Of cold waves make
their appearance In the Northwest east Of the
t It also S PrS S
cold air from the regions OF perpetual snow and
leo at the north. But why that region should
north pole than .other sections, where cold
waves. form less frequently or not at all. is an
Theories have been advanced based upon the
vastness OF the plains In that region and their
capacity for absorbing and giving of heat. but
no theory on the subject has been generally ac-
cepted. and tho greatest meteorological author
tiles In the country do not attempt to, explain
may form ut any moment. They seem to de-
pend not at all on the time Of day. and but TO
limited extent on the season OF tho year. They
Lieut.. Thomas n. Woodruff the ofiicer in
charge OF tho indications office. in st Paul.
connected come with. the chief weather ofilce In
Washington, and the results OF this study are
hotes h series, published d in 1855. ha The pamphst h
with reference to, this subject. Lieut. Wood
charts Of the years 1851 to 1854 inclusive. After
stating in general way that q iall Of tempern-
eter; that a rise precedes such an area, and
that with respect TO an area OF high barome-
ter the rise % and isll qt 81 temperature temp usually
Areas Of high and low barometer move almost
Invariably across tho United States from west
to east, Most areas Of low, baromete.r are form
ed In the region east of the Rocky Mountains:
and as these low arsas move eastery, tho high
snS we ,Ss hare es Tod wave Of or
Then it Is shown that in the four years under
consideration. IA Of tho cold waves observed
cam 9 down the east side OF these mountains
from the British Northwest Territory. while "a
ether Soa sI aH E
cold waves in the Northwest appeared first at
Helena. Mont. and these few exceptional ones
Conclude" conc 5 adds s. Lieut. Woodruf. that these these
waves have their origin in tho vast regions Of
Ice and snow near the arctic circle far to the
With respect to their progressive motion,
cold waves are divided into three classes:
country from west to east, and which follow an
almost invarin5le path along the ehnin ir. OF
do done not extend to the States south Of the Ohio.
Second-Those which move In a southeaster-
!y direction and cover the entire country in
.Third-Those which move southerly, from
Montana r., and % Dakota r 10 Texas hsnse
~ t over the m Atiant c coast States. It sometimes
occurs with this class that the cold wave is first
felt in st. Louis and Shreveport before being
felt at st. Paul and Chicago. and that then the
ward Of tho second class,
Inc SecOnu CLASS was tn0 most numerous IN
was very variable. Considering Helena rs tho
first point of observation. there were six cases
at ST. Paul and Helena 10 in which It reached
st. Paul s hours after its appearan at Helena.
in ~ hours in Is hours % and Il in = Il hours
From this it will be seen that Of all the cold
waves that reach st. Paul from Helena, "a. per
rule 1t is found that the maximum effect Of
cold wave occurs at each station In very short
erally within twenty four hours, and often at
the northern and western stations at once.
There are many other curious facts CON-
instances occur, says Lieut.. Woodruff. where
the temperature at given station. at the time
northwest is lower than the minimum after.
ward produced BY the cold wave. 1t often
shat cold sets in the
Mississippi Valley divides. q part going ing
horth,esasterly. to the lower lake region f, and
greatly diminished. This action S'' 'soems gen.
orally to be due to the sudden M deyelonment nt
sight energy remains in Kansas Missouri. and
tardine. or even totally destroying cold wave
Again, when a cold wave is retarded in this
raps
feature is that after a cold wave commences
west and another wave Is formed entirely
distinct from the first, from which it becomes
separated by warm wave. Tho warm wave
Is only a narrow belt, but the cold waves are
perfectly distinct.
The tables prepared by Lieut.. Woodruff show
severe in the months of January. February.
and March although some very severe ones do
mako their appearance in other months OF the
year. Also It appears that the most decided
changes Of temperature appear upon the 3 p.
NJ. charts of the Signal Service. and that the
mo n onStS
low severe storms. The prediction Of the prog.
ress of cold wave is attended with n good
deal OF difficulty, largely on account OF the fact
that there Ia no way Of determining which Of
the three paths IL will take