New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1899-04-29

The tornadoes and thundsrstorms which occurred
In Missouri and Iowa Thursday evening belong
TO type Of disturbance peculiar to warm weather.
They local in character. but bear a well-de-
fined relation TO the large general areas Of low
barometer that are forever crossing the country
from west to east. The parental depression was
central on Thursday morning just north Of East
ern Montana. and the barometer there read about
$50 inches. The low area was wedge shaped and
its tip reached down over the Rio Grande into
Mexico On It's eastern front the temperatures
were high and the air moist owing to the prev
alence OF generally southerly winds On the west
ern flank the air was cold and dry and the winds
northwestery. At the hour Of simultaneous OBJ
servation In the morning. the Thermometer stood
at 70 in Des Moines and 36 in Miles City. Mont.
Sharp differences OF temperature and humidity.
such were here indicated. are the usual con-
ditions preceding outbreak OF local storms. And
although II Is not practicable to predict with pre-
csion just where they will occur. 1t is noticed that
they most frequent In the southeastern part OF
depression. from 300 to 900 miles from the centre.
An abundance OF thunderstorms was developed
in the lower Missouri and upper Mississippi val
leys Thursday. but II Is not quite clear that
more than two fullhedged tornadoes were formed
One, passing in an eastery direction in Northern
Missouri, swept through Sullivan and Adair coun-
ties. first visiting Newtown in the former and then
Kirksve in the latter. These two places are about
forty miles apart. The tornado itself probably do
not exceed quarter OF mile In diameter. and Its
track may not have been much more than fifty
miles in length At any rate It is not easy to iden-
tfy 1t with any other disturbance reported As
the average rate of progress Of these "twisters
the country is something like twenty-five miles
an hour the Missouri tornado may have lived
longer than most OF these storms do and had a
corporate existence for nearly or quite two hours.
But the length Of its stay in any one village could
not have been more than a minute or so.
The other wel-defned tornado made It's appear
ance In the extreme western part Of Iowa. further
west and more than 100 miles further north Onawa,
where It seems TO have made its debut. is In Mo-
mona County. and there are indefinite accounts OF
damage wrought by II in the next county eastward
Crawford. That this second disturbance was less
destructive than the first does not indicate that IT
was less severe The most natural explanation
of the difference Is that the path OF one Jay over
II would not be al ali strange II other tornadoes
formed substantially the same time as these TWO
but bs h Western ss people are fond
calling a cyclone although the storm winch
fsr@is the most severe and the narrowest Of all
local weather disturbances. thunder;showes often
Il advances eastward and It has depth OF mile
more from front TO rear When once boer ia o9
over II is suspected that circulation OF AIR taxes
place in It something like horzon.a ~ r9 1bs earth
seldom has diameter of over 1000 or ZOO feet II
lives sGgT II h e 5w deve
ment II is practically vertical c1umh m. more OF b
less distorted by swayng motion IKE tns, VI w
taperng part OF balloon. The awfu violence 90, Oh
which It is capable is due not TO its progiesSsIve
motion which Is the same that OF thunder
suua but to It's terrific rotatove power. tne[s Il
'twster but It has been estimated that Tor an IN,
slant something like speed OF 800 or Luz" miles IN
| hour Is manifested - ,.u...~r,
Although the tornado, thundersorm hailstor ars
winds0uaII and other related local disturbances are
very short lived II occasionally happens tnat new s
crop generated each afternoon ana ts esh nw
! OF which they are all the offspring moves across
| the continent. The most violent CONCENTRATIONS
! however, are usually confined 10 Single ua''