MONTHLY WEATHER REVIEW
The inception of these depressions is due to special conditions on the Adriatic slo e. We may a r m these
arison with those of adjoining regions, followed by Secreases in pressure. I n this case, under the influence of important de ressions existing over northern Europe,
consider as secondaries. If an anticyclone is present at the same time in north or northwest Europe, the depression develo s more
creased almost equ y in t e various sectors, and, coin- cident with an extension of the area of the cyclone, the pressure decreases, and the cyclone moves toward the east, while the anticyclone likewise shows a movement, but toward more southern 1at.itudes. However, if the western antic clone, which we may
of these secondary de ressions, the other anticyclone,
is not less important. We mag regard this anticyclone as an indefinite one, because it does not represent in general more than a zone of relatively high pressure as
com ared with that of adjacent regions. T%e two currents of air, the one cold, the other warm, which, according to the theory of Bjerknes, are necessary to the formation of a de ression, may be engendered by
the other in southeastern Europe. [Details of depres- sion of December 20 and 21, 1923.1 These de reasions form preferably during the winter months an a are entirely lacking in summer, for the dis- tribution of air temperature at that season facilitates their formation in the valley of the Po. Thus, the conditions favorable to the formation of these secondar de ressions would be the following:
areas of high pressure extending, the one over the British Isles, the other over the Levantine Sea [eastern Medit,er- ranean]. The depressions, as soon as they are formed, move as a function of the nioremont which the antic -
Levantine Sea thus exercises the major influence.
conditions to be, very limited t R ermal differences in com-
there form on t T l e Adriatic depressions which one may
deeply and forms a r y y cyclone. The gra B ients in-
assume to be well developed, in I uences the movement
which exists over the I! evant, exerts an influence which
these two anticyclones, w R ich lie, the one in northwestern,
A very marke B f cyc one over northern Russia, and two
clones undergo. The nnt,icylone dominant in t z c
NOTES ON THE WEST INDIAN HURRICANE OF OCTOBER 14-23, 1924
By CHARLES L. MITCHELL
[United Staten Weather Bureuu, Wmhlngton, D. C.1
Rdcent reports indicate that the hurricane of October 14-23, 1924, was one of great intansity. Dr. Jose C. Millas, director, Observatorio Nacional, Habana, Cuba, writes: “I believe that this hurricane is one of the most severe ever m erienced in our latitudes.” Doctor Mil- las has forwar ed a number of hotograph clipped from El Mundo, Habana, taken in os Arroyos and Arro os
de Mantua, Pinar del Rio Province, which suggest tgat the force of the wind was almost comparable to that in a tornado. The steel wireless tower at La Fe was blown down. It is, indeed, fortunate that this hurricane passed over no land areas other than the extreme w&tern end of
Florida. f i l l been received reporb indi- cate that in Arroyos de Mantua about a dozen persons were killed and 50 injured and that almost every building
E B
in the town sustained heavy damage, besides the severe damage done to the tobacco crop. A maximum wind velocity of 72 miles an hour from the south was regis- tered at Habana at 10 p. m. of the 19th, although the barometer fell little, if any, below 29.50 inches. The lowest pressures observed at a number of stations in western Cuba and also very complete barometric data from the S. S. Toledo, all kindly furnished by Dr. Millas, are given below:
CUBAN STATIONS. OCTOBER 19. I924
Jnches Gunne ____. . . ____ __ _.__. ____. . -. .____ ._______ _______ ___. 28 m Dlmas ________________________________________----------- Z54
La Fe- - - - - __ - __ __ - __ - - ___ - - - __ - _______ ____ __ 35 Pinnr del Rlo _________. __________________________________ 29.28
nfantua --______ ___________ _____ __ ___ _______________ _____ 28 15 Loa Arroyos. - - ___ _____ -. ______ ____ ______________. _______ 27.52
8.6. “TOLEDO” NEAR JUTIAS CAY (OFF THE NORTHWBSTERN COABT)
__ ___
The following extracts are from a report of an inter- view that the meteorologist of the Panama Canal Zone had with Ca tain Burmeister, master of the United Fruit Steam &up Reredia:
* * * A t about 7 p. m. (October 18) all three ships (the Sun Bruno, Turrialba, and Heredia) left Havana Harbor and preceded toward Cape San Antonio. At first there was practically no wind, but as they steamed west the wind went around to east
and northeast and gradually freshened up. There was a fairly heavy following sea. The wind gradually became heavier and the sea higher. At about 3 a. m. (October 19) the master of the Sun
Bruno * * * decided that the center (of the storm) was to the westward and he radioed the other ships that he was going to turn around and steam toward the northeast. After debating at some length, Captain Burmeister also decided t o turn around. At this time the ships position was about 23’ 50’ N. and.84’ 10‘ W. The ship was headed north-northeast for a while and then north. The pressure dropped steadily. At 4 a. m. the barometer read 29.56 inches and the wind northeast force 4. At 6 a. m. the sea was so high that the captain decided to heave to. A measage to that effect was sent t o the two other ships. At 8 a. m. the pressure was 29.44 and the wind had risen to northeast 8. The ship was empty and i t bobbed around like a cork. At 11 a. m. the pressure wsa 29.15 and the wind northeast 11. * * * At noon the barometer read 28.10 inches. This was a drop of 1.05 inches in one hour. At that hour the wind was blowing from the northeset force 12. The following is a vivid description of the storm at its hefrht by Captain Burmeister: The whole sea was a boiling, seething mass. It was impossible to see any distance. It appeared as if the surface wme covered with a mais Qf turbulent steam. The sea waa breaking in such manner that it was impossible t o tell whether the water in the air
was rain or sea water. I estimated the wind t o be blowing 120 m. . h. I ordzred every pound of steam to be used in keeping her unler control.
498 MONTHLY WEATHER REVIEW O ~B E R , 1024
There was water in the staterooms and even in the captain’s room on the bridge. The following note was written in the log at about this time: “Hurricane winds with high seas. Ship laboring heavily. Taking heavy seas over forward and after decks.” The pressure dropped t o its lowest point a t 1 p. m.. 28.05 inches (a test of this barometer at 28 inches showed that i t was reading too high by 0.20 inch, making the corrected reading 37.85 inches). From 11 a. m. t o 2 p. m. the wind blew with hurricane force, and waves were mountainous. After 1 p. m. the pressure rose quickly and by 4 p. m. it was 29.30. A t 5 p. m. there was noted a backing of the wind, although the velocity was still high, nort.li-~~ortheast
10. As the wind continued to back the velocity decreased. By midnight the pressure had risen t o 29.55 and the wind blew froni the northwest with a force of 6.
The following is quoted from the report of the oificial in charge of the Weather Bureau office at Key West,:
The storm’s center at its nearest approach to Key Wrest was 90 miles distant. This was about noon of the 20th, when the center
Notwithstanding the strong and consistently increasing winds which began during the night of the 19th and which culminated at 2 p. m. of the 20th with a maximum velocity of 66 miles an hour from the southwest, this storm caused no damage in Key West aside from some little damage to trees and shrubbery. There was no damage to shipping whatsoever. This was unusual in the face of a wind that for 17 hours maintained a velocity averaging 51 miles an hour, with gusts ranging from 54 to 74
miles an hour, and can be ascribed only to timely and persistent warnings issued by the Weather Bureau. Taking advantage of these warnings, all vessels, large and small, were made secure, windoas and doors battened, and in a number of cases trees trimmed in order to lessen the wind effect and possibly save them. As a result of warnings broadcast by radio, several vessels Rought refuge in port. All P. & 0. steamers were held on advice from this office. The following vessels were held in ort pending the passage of the storm: Steamers W. F . Btwdell, 3. R. Gordon, Roarroke, Eslrada Pnlina, Henr M . Flagler, Joseph R . Parrolt, Mianti, FPilliam Islam, and dovernor Cobb, and the schooner Mary Thompson. The bureau’s work on this hurricane has called forth much praise from outside sources. bore northwest.
$3 7 /.5 0 ci (oz.) NOTES, ABSTRACTS, AND REVIEWS
WETTERVORHERSAQE (WEATHER F0RECASTING)l
This volume is No. XI in the series of natural science ublications brought out by Dr. Ra hael Ed. Leisegang,
structor in meteorology in the University of rnnldurt and has written a number of papers on met.enrologica1 subjects, especially within the last few years. After sketching in Chapter I the development, of
weather forecasting since the time of Dove and indicating the synoptic weather re orts available to European fore-
ing them, t.he author proceeds, in Chapter I-The de-
pendence of the weather on pressure forma.tions and air streams induced thereby-to discuss the prohlenu of weather forecasting from synoptic weather charts. His method of developing the subject is quite naturally that, of an instructor in meteorology. He begins with the fundamental concepts of air niove- ment as dependent upon the pressure distribut.ion with such modifications as are introduced bjr surface friction, the rotation of the earth on its axis, and other influences,
9
hankfurt-am-Main. “he author, 8 octor Geor ii, is in-
K
casters, together with t E .e means of collectin and chart-
agraphs. According to Exner, in the original stationary condition the isotherms and the isobars run parallel to each other. North of the line of discontinuity pressure is relatively high; south thereof relatively low. Normally po1a.r air masses have an east-west movement. These winds, how- ever, meet obstacles to their free and unobstructed west- ward movement, as on the east Greenland coast, Spitz- bergen, and elsewhere in high latitudes. The winds are then deflected toward the south by the configuration of the earth’s surface.
1 Wetterwrhersage, W. Oeotgii, Dreaden und Leipzig, 1924.
Since these masses of cold air by reason of their greater density are associated with higher pressure, the isobars in accordance with the cleflection of the winds become curved toward t.he south. In the advanced stage the tongue of cold air forms more and. more an inclosed center of high pressure with anticyclonic movement. The warm west winds which here have been lifted from the ground by the cold air masses still blow (aloft) over the tongue of cold air and on it.s front side cuerts a suction effect on the lower masses of warm air similar to that observed on the leeside of inountains on the passage t,heroover of t.lie wind. A s a result, this suction effect will protluce on the front! side of the tongue of cold air a dynamic pressure ciiminut.ion which intensifies the already present low pressure thermally caused. On the front side there are supplied to this cyclone thenceforth additional warm air masses. Thus, the cyclonic information acquires new energy through the intensifying of the temperature contrast.. Finally, the up er wind blowing over the tonoue of cold? togclther wit{ the movement of the lower cord and warm air illasses resulting froni the cyclonic formation, prodiice a inigrat.ion toward t.lw east. After the tongue of cold air lias moved eastward of t.he point of invasion the earlier stationary condition gradually reestablishes itself until marked temperature contrasts have again developed, which prnduce a further sudden advance of cold. In this way t.he inrushes of cold and the cyclonic forma- tions become a periodic process which recurs at int.emals at cert,nin definite places on the earth. Since the cold air niasses disengage themselves droplike from the polar reservoir of cold, Exner’s theory is called the “drop” theory of cyclones in contrast to Bjerknes wave theor The auttor makes the distinction tliat both the B’erknes and the Eamer theories explain the ori in only o / one group of cyclones, viz, that which is foun% in the lower levels-2 to 3 km. where t-he pressure differences me thermally produced. I t is not clear just how a distinction is to be made in uctud forecast,ing between the influence of the two res ective groups-those originat.ing in the lower levels
aii s those having their origin in the stratosphere. The closing chapter on !‘long-range weather fore- casting’, brings forward little that is new or suggestive, perhaps for the very good reason that witsh the exception