JANUARY, 1906. MONTHLY WEATHER REVIEW. 31
The roof of the large auditorium was nearly intact, but near its south-
east end a great hole was torn in it, say twenty feet square, and the
plece, which was intact, seemed to have been blown upward, twisted
almost completely around, and then dropped back into nearly its original
position.
Now in each of these buildings there was a large amount of air inclosed, with no dividing partitions. According to my view the tor-
nado simply took the air pressure off their sides and t,ops, and in cmse-
quence the inclosed air expanded from within and did the greater port.ion
of the damage. It was not the force of the wind outside, but nictiulythe expansion of the confined air, that wrecked the buildings. Suppose that.
such public buildings should be so made t h a t a space of, say, ten feet, all
around just beneath the roof, could yield to a moderate pressure from
within, would not the roof remain intact and the walls reniain vertical?
A few days ago I examined some hailstones under a sinall-power mi-
It has been said that hailstones all have a snowball for a
HAILSTONES.
croscope. nucleus. I think that t h i s is a mistake. The white central
the hailstone, inclosed in its rim of cryst,al, gl
ice. P u t some water in a drachm vial and fr
freezing mixture, consisting of two parts by weight of ice to one of salt,
hold it up to the light, and you will find a central core of white amor- phous ice, with crystalline ice enveloping it on all sides. There is no
snowball to start with in this instance; t.lie freezing always begius on the top, bottom, and sides, and the liquid center freezes last. I fully
believe the hailstone is flrst a spherical ilrop of water; then it,s outer-
most rim reaches 32O F. in the surrounding c,olc\. congeals. ani1 the iwn-
gelation gradually extends inward till the last. of the liquid content
becomes solid. Water can not be frozen in a tuhit or in any sort of way
so that it will not he white in t,he cent.er if the cold strikes it 011 all
sides. Boil water, pour castor oil on it befure it has a cliance t(n reab-
sorb the three per cent of air that iiatiirallg helongs to it, fre(.ze it., and you get amorphous ice (never crystalline.). looking like parafinr. The
central core is larger in the hailstone, in proportioil, than it would be
in a piece of ice of the same diariieter frozeu natiiritlly in a tuI.ie or other
vessel. This is because hail forms four to eight miles above the gruiiiii1
and there is less air in the wat.er a t that height than at the groiinil,
where the pressure is 30 inches.
hail.
cover it with another block of ice, and the two will uuit,e solinlly, eveu
when the temperature outside is above 38O and t,he out,sitlrs t ~f both
blocks are in a melting state.
I think that large hailstones are simply aggregat,ions itntl t 4 i i
Melt the top of a block o f i w so that i t is co\
THUNDERCLOUDS.
A thundercloud is composed of fog particles, thew particles being
much smaller, according to the laws of gravity, at the top than at the
broad black base. It seems to me that meteorologists generally teach
that it is the condenbation and coalescence of these particles that form
raindrops, and that this coalescence takes place IJY the action of cold,
and that it begins when the dew-point is reached. This is true in regard to fog particleh only, and f~ig particles have still further to be condensed
IAoie they 1o*e their spherical hhape, and this requires a much greater
degree nf cohl than any one beems to haw thought necessary so far as 1
can learn. Mists abet e rivers or fvgs on the coast are seen when the
temperature is far lielow freezing. In other words, fog particles will
not c~ctlesce a t temperatures below freezing.
\Ye will suppose the peak o f a thunllercloud to reach eight and one-
half iiiiles. That height ou a suininer day has a temperature of a t least
-5W F., anil yet you see before yuu it nia5S of vapor, boiling and seeth-
ing, jobt as +team from an engiiie doeb on a cold morning. Heat from helow is continually being supplied, and however cold the interior of the
cloiitl may be, it is evidriltly not sutfiuiently $0 to condidate the vapor.
The I ery nioiuent, h o ~ ever, that the vapor reaches the top edge of the
cloud and en~~~)tiiiters -SOo F. of coltl, eac.11 spherical fog or cloud particle
is so con+trivteil ulion its inclobed, nom much rarefied, air particle that
tlie latter forces its way out just l i b the bursting of a soap bubble, and
nom instead of a flliu of water surrounlling a globule uf air you will have
lett a tiny niasb of Kenuitie, unadulterated water. This has appreciable weight, f d l h duwuward, rnptriring by coiltact in itb descent countless
awentliiig fing particalrs, coalewing m ith them. ancl by the time the base
t>f thr c.lourl is reached a large drop of raiu ha5 been fornied. Thus rain begins a t the very tnp lityer o f the niass of fog particles and nowhere
e1-e. The higher the cloucl, and the greater the nurnller of fog particles encountered 111 the deb ut, the harder the rain. Every thundercloud
zhows the rain streak d ectly helow the peah. A flash of lightning or peel o f thunder is never noticrd till thohe raiu streaks appear below.
We print, the ahore AB coming from a close observer and
logical reasoner, but clonbtless others will differ from him as
to facts and t,heories. The forinat,ion of hail and rain is not
yet well underfitood. We hope that others will contribute to
this subject; observations, theories, and experiments by care-
ful physicists are much to be deSired.-EDITOR.
FOREOASTS AND WARNINGS.
By Prof. E. B. GARRIOTT, in charge of Forecust Division.
North Atlantic weather was not notably severe. Baromet-
ric pressure continued low over the British coasts. After the
4th high barometric pressure and settled weather prevailecl
over the Azores.
Ten areas of low baroiiieter moved eastward over or near
the Canadian Maritime Provinces, one of which advanced from
the Gulf of Mexico, one from tlie subtropical region north of
Cuba, and one from the north Pacific coast of the United
States; the remaining low areas first appeared over the in-
terior of the North American Continent.
Over the greater portion of the United States the month was
exceptionally mild, and in parts of t,he Missouri and Red River
of the North valleys the mean temperature for the month was
10' to 12' above tlie normal. Precipitation was irregularly
distributed, and there was a general deficiency in snowfall.
I n the Atlantic coast States the barometric depressions were
of moderate intensity. Several energetic storms crossed tlie
Great Lakes, those of the 3d--ith, 5-Gth, ancl 14-15th being
the most severe. The principal storms of the Pacific States
occurred during the second decade of the month.
Attending low area I heavy snow fell in New Mexico on the
lst, and heavy rain in the lower Mississippi Valley on the 311.
On the 311 the barometer fell to 38.66 inches a t Madison, TT'is.,
a t 8 p. m., snow fell in Iowa, Minnesota, TVisconsin, and Upper
Michigan, heavy rain generally east of the BIississippi, and a
strong gale prevailed over the upper Lakes. A tornado is
reported as having visited Blbany, Ga., a t 2:30 1'. m. Snow
continued in the Lake region during the 4th. I n conuection
with low area I1 high winds prevailed from the Great Lakes
over the middle Atlantic and New England coasts. During
the passage of low area I11 snow fell in the Ohio Valley and
tlie Atlantic States to and including North C'arolina on the 8th.
From the 12th to 14th low area IV moved northeastward off
tmhe Atlantic coast with gales that attained a reported masi-
inum velocity of GT iiiiles an liour from tlie northeast a t Nan-
tucket, Mass., on tlie 14th. From the 11th to 13th low area
VI caused heavy rain and high winds, on the Pacific coast.
During the 15th and 16th low area VI1 passeed northeastward
over the Lake region, with rain from the loT5er Mississippi
Valley over the Ohio Valley and Cheat Lakes. From the 16th
to 18th low area VI11 crossed the continent from the north
Pacific coast to the Chadian Maritime Provinces. On the 22cl
heavy rain fell in the lower Mississippi Valley, and rain, sleet,
ancl snow in the midclle m c l upper Mississippi valleys, and on
the 32~1 heavy rain was general from tlie Ohio Valley over the
middle and east Gulf Stat,es, aucl snow fell oyer the upper Lakes.
On the 26th heavy precipitation attended the passage of low
area SI northeastward 08 the Atlantic coast, and snow was
reported in the interior of South C'arolina and Georgia.
The first and most important cold wave of January advanced
over the interior and eastern parts of the country from the
19th to 24th, breaking a period of exceptionally high tempera-
ture that had continued generally east of the Rocky Mountains
from the beginning of the month. During the 30th and 31st
a moderate cold waye arlvancecl from RIanitoba over the Red
River of the North and the upper Mississippi valleys.
Heavy frost occurred on the iniddle coast of tlie Gulf of
Mexico on the h t , 9th, 14th. 23~1, and 3dth, and on the Texas
coast on the 34th anil 25th. Freezing temperatures mere re-
ported a t New Orleans, Nobile, and Pensacola on the 9th, 2313,
32 MONTHLY WEATHER REVIEW. JANUARY, 1906
and Nth, and at Coi-pus Christi on the 23d and 24th. From the
1st to 6th heavy frost was reported daily in southern California.
The mean temperatures of the month were decidedly above
normal in all sections, and the maximum readings that occurred
from the 21st to the 24th were among the highest recorded in
the January official observations. The warm weather during the
period mentioned caused buds to start on some trees ancl leaves
to appear on shrubs in sheltered placeb in central aud southern
sections. Ice disappeared from many streams and pondn.
There was an absence of severe storms, with the exception of
the storm of the 14-15th, when wind velocities of from 40 to
67 miles an hour occurred at coast stations. So far as known
at this office no damage resulted from the gales. The pre-
cipitation of the month was generally much below the
monthly arerage, and the greater portion of i t occurred as
rain. The light snowfall was unfavorable to the lumbering
interests, and, owing to the prevalence of inilil weather, there
has been little ice harvested. There were no storms during
the month with high winds for which warnings were not
orderecl.4. Ti'. Sttii//t, L)istric.t Forecastrr.
BOSTON FORECAST DISTRICT.
NEW ORLEANS FORECAYT DISTRICT.
High winds prevailed along the west Gulf coast on the 9th
and 22d, for which tiniely warnings were ishuecl. No high
winds occurred without M arnings. Two general cold waveb
passed over the district during the month, one on the 8th and
9th and another on the 21bt aud 23d. Frost or freezing teni-
perature warnings were issued for tlie sugar and trucking
regions of Texas ani1 Louisiana for every injurious condition
that occurred during the month.- I. Jf. C'linr, District Fwrrxstw.
Advices of impending stornis were sent to open ports on
Lake Michigan during the month. A well-marked storm
developed in the southwest early in the iuontli and reached
the middle Mississippi Valley on the morning of the 3d, at
which time messages advising the rarious interests that se\ ere
and dangerous gales would occur were issued. The storm
continued to develop great energy and moved directly across
the Lake region, accompanietl by general galeh for 24 hours.
Advices were sent out on the 4th that the storm would gratlu-
ally lose force. There was no other severe storm until the
15-16th. Advisory messages mere issued in advance of this
storm. The storm which appeared in the Pacific coast region
on the 17th moved very slowly southeabtward and thence
northeastward over the Lake region, reaching the Lakes by
the morning of the 22d and causing high winds until the
morning of the 23~1. Advices were sent out 34 hours in acl-
vance of its occurrence.
There was no general cold wave during the month, althougli
the temperatures were very low in the northwest from the 2lst
to the 23d. Cold-wave warnings were issued on the lCJth,
20th, 21st, ancl 23d, resulting finally in a display at all statious.
The warnings were verified at the majority of the stations, and
a remarkable fall in temperature occurrett at practically all
points, although limiting temperatures were not reachecl in
some cases. No other general cold-wave warnings were issued.
The chief value of the warnings lag in the fact that a1)normally
high temperatures for the season had previously prevailed.
This storm was accompanied by rain, changing to sleet ancl
snow, which caused great dainage to telephone and telegraph
lines. The temperatures were, as a rule, far ahove the normal
over the greater portion of the district, and it was the warmest
January since 1880.-H. J. Cox, Prqfrssor slid District Forwadrr.
The month was unusually mild ancl fair, there being only
two periods, 8 4 t h and 23tl to 26th, when the temperature was
below normal. On the 20th and 21st the temperature was 70'
to 80' over the greater portion of Kentucky and Tennessee, the
highest generally for January since the establishment of the
CHICAGO FORECAST DISTRICT.
LOUISVILLE FORECAST DISTRICT.
National TiTeather Bureau Service. Thunderutorms were quite
general on the 15th. Three general storms passed across or
near the district during the month, giving rain and high winds;
these occurred 2-311, 14-15th, and 20th-22d. The month was
remarkably free from snow, there being only one snowstorm,
on the 8th, over any great portion of tlie district. On the 26th
snow fell quite heavily in the mountain portions of Kentucky
ant1 Tennessee, but none elsewhere in either State. Cold-wave
warnings were issued the night of the 7th and morning of the
Stli, and again on the 20th and 21st. These warnings were
fully justified.-F. J. H'ak, District Forecaster.
DENVEH FORECAST DISTRICT.
I n western Montana and in the inountnin districts of the
mesteru slope the month mas cold, with here ancl there an ex-
cess of precipitation, while mild and dry weather was almost
continuous in the plains region of the eastern slope. In south-
western Colorado the stormy period of the 18th, 19th, and
2Oth, which was forecast, was followed by the most destruc-
tire snow slides in the history of San Juan district. Five lives
were lost fron~ this cause, ancl the Denver and Rio Grande
Ridroad was hlocked for thirteen days in Animas Canyon.
The greatest depth notetl in connection with these slides was
63 feet. The most iiuportant cold wave of the winter followed
tlie low pressure area that overlay the middle Rocky Mountain
r?gion on the morning of the 20th. Timely warnings were
jiiven f ill1 distribution in southern T17yoming, northern Arizona,
southwestern and eastern Colorado, ancl northern and eastern
New Mexico, which was the area covered by the cold wave.-
F. H. B i .~~i ~f l ~,/~b i i ~.!~, District Fow.c~trster.
SAN FRANCISCO FORECAST DISTRICT.
The iiionth, as a whole, was pleasant, the condition during
the early portion being favorable for heavy frost generally in
the interior of California. Ample warning mas given to fruit
growers, ancl losses due to frost were therefore small. On the
morning of t,he 11th a general warning of rain and southerly
winds was issued, and the storm that followed broke a pro-
longed dry period that was beginning to seriously interfere
with farming operations. Ample warning was also given to
river interests concerning the probable effect of the heavy
rains upon rirer heights. The third decade, like the first, was
dry.- A . (+. XcAd ir, Pr?fessor and District Fowcaster.
PORTLAND FORECAST DISTRICT.
The storniy period of the month was between the 11th and
the 25th, during which time four noteworthy disturbances
passed across the district. The third one evidently resulted
from the coalescence o f two minor disturbances, which were
first noted over Nevada and western British Columbia, respec-
tively. I t moved east across the southern portion of the
district. The last one made its appearance off Cape Flattery
on the evening of t,he 21st, and moved slowly northeastward.
The steamer Thlrwia \vas wrecketl on Vancouver Island during
the passage of the last storin and 117 lives were lost. From
the 35th to the end of the month, the weather was controlled
by a stagnant high pressure area which settled over southern
Idaho, and hut little precipitation occurred thereafter. Timely
warnings were issued for all gales. No cold waves occurred
and no cold-wave warnings were issued.-E. 8. Reals, District
Forrcastrr.
RIVERS AND FLOODS.
Owing to the continued absence of normal winter condi-
tions, rirer stages were generally higher than is usual during
the month of January. Temperatures were high and rainfall
abundant, and, as a consequence, the great rivers were well
supplied with water, while moderate floods occurred in many
of the smaller rivers. Danger-line stages were exceeded in a
number of these floods with the usual accompaniment of
flooded lowlands. Along the headwaters of the Tennessee