36
Timeof lowest began barometer
MONTHLY WEATKER REVIEW
OCEAN GALES AND STORMS, JANUARY, 193bContinued
Low- est "le ba- ended rom-
eter
JANUARY, 1930
direction
Voyage
Shift8 of wind
near time of low- est barometer
Position at time of
I loweat barometer
11 ._____
11 ______ 9 _._____
12 ..____
12 ______ 12 ______ 13 ______ 13 ._____
13 ______
13 ______ 13 ._____
14 ______
V d
1
From- I Tc- llatitude
-~____
Inchca 1 p., 11 ____ 13 ______ 30.02 Zp., 15 ____ 16 ______ 29.30 Noon, IO-- 10 ______ 29.68 Sp., 12 ____ 13 ______ 29.68 2 a ., 15 ____ 16 ______ 29.57 Noon, 15-- 17 ______ 29.57 8 a., 14 ____ 14 ______ 28.60 5 a,, 13 ____ 14 ______ 28.96 4 a., 14 ____ 14 ______ 29.85
1 p.. 16 ____ 16 ______ 28.81 -, 16 _.____ 21 ______ 29.08 1 p., 14 ____ 15 ._____ 29.16
I I I D ,
North PmdEe O m -
Continned
San Francism Honolulu---- San Pedro.--- Honolulu---- San Francisco Coos Bay---- Victoria.---.- Kobe __.______
_____do ________ Seattle _______ Los Angela.- San Francisco ___-.do ________ Seattle _______ _____do ________
Courageous, Am. M. S--
Emp. of Asia, Br. 8. S---
Lubrico, Am. 6. 6 _______
33 23 N 27 49 N 38 07 N 47 50 N 34 12 N 47 09 N 49 41 N 33 10 N 33 aS N 49 40 N 33 20 N 40 40 N 39 58 N 60 29 N 44 00 N
Do __________________ _____ do _______ _____ do _______ 23 00 N KaIsho Mar- Jap. 6. 6-. Mumran _____ Vanconver-.- 49 60 N Hawaii MaruJaD. 8. 6.. Ban Pedro ____ Yokohama--- 30 05 N
Lowest
-.
Inches
ao. 60 29.14
ao. 00
29.60 29.72 29.18 29. as 29.06 29.75
ao. ia
Wilhelmina h: 8. S---
Tahchee, B;. 6. S ________ Cin alase Prince, Br.
d8 -. Seattle Am. 8. 8 ________ Hagodate ____ Seattle _______ 60 a0 N Glentdorth Br 8. S ----I San Pedro ____ I Kobe- __ _____ I a3 36 N Kurohime 'M&u. JBD. Wakamatsu-. Gram Harbor, 50 00 N
Longitude
e ,
120 56 E 148 E4 W 146 45 W 1M 30 W 151 00 W 175 00 W 131 16 W 172 13 W 175 40 E
152 26 W 170 58 W 158 30 W
16400w 147 00 W 158 55 w 125 45 W 179 06 E 168 40 E 166 00 W 169 50 E
178 40 E 155 20%' 152 29 E 160 25 TV
159 48 W 157 00 E
164 33 E
NORTH PACIFIC OCEAN
By WILLIS E. HURD
A very unusual average pressure condition character-.
ized the weather of the central and northern portions of the North Pacific Ocean during January, 1930. The
Aleutian cyclone, which ordinarily appears centered over
the Gulf of Alaska or nearly along the chain of the Aleu- tian Islands, now lay farther southward in midocean.
To its eastward the California-Pacific anticyclone, al-
though a t times occupying its normal position, was for the most part restricted to extreme eastern and north-
eastern waters. The average oceanic maximum of about
30.30 inches covered the upper eastern part of the Gulf of
Alaska and British North America. The average barom- eter at Juneau and Kodiak was, respectively, 0.56 and 0.45 inch above the normal. This anticyclonic condition gave
the lower Alaskan coast, as exemplified by Juneau, the
clearest skies on record for any month. Over the central and west-central parts of the ocean, between latitudes 30'
and 50' N.,the low pressure was associated with extraordi-
nary meteorological activity, marked by high winds, fre-
quent rains, snows, and hail squalls, departures from the usual prevailing winds, and the extension of abnormally
low monthly pressures into tropical latitudes. At
Honolulu the negative pressure departure was slightly more than a tenth of an inch. At Midway Island the
average pressure was 29.89 inches, which may be com-
pared with the value of 29.81 inches in January, 1916,
when the absolute minimum of record at that station occurred. In the Far East more normal conditions prevailed.
Several minor cyclones appeared in various parts of the
sea, but during most of the month high pressure overlay China and the adjoining coastal waters, with the result
that the northeast monsoon prevailed from the Eastern to the China Sea with few intermissions.
Barometric data for several island and coast stations
in west longitudes, including Point Barrow on the Arctic Ocean, are given in the following table :
29.09 29.64 29. 07 29.54 29.25 28.45 29.18 29.52 29.52 29.32 29.51 3 .7 2 28. 78 28. 76 29.18
lowest gale b% I barometer I ended
NNE, 9---
w ,9 _-__-- wsw-w. SE, 9 ______ SE-SSW. NW, lo--- SW-NW. E 12------ 4 pts N'W, L-- NWIWNW. N 9 _______ N b 11 ... W-NW. NW: 9---- WSW-W.
N E 11 .... E-ENE.
E,'ll______ ESE-E. I
w i2-----
TABLE 1.-Averages, departures, and extremes of atmospheric pressure at sea level at indicated hours, North Pacific Ocean and adjacent waters, January, 1930
Average pressure Stations
I-
Point Barrow 1 f _______________ Dutch Harbor 1 __._____________
St. Paul 1 ...................... Kodisli. 1 ._____________________
Midway Island 1 4 _____________ Honolulu 6 ..................... Juneau 6 _______________________ Tatoosh Island 6 6 ______________ San Francisco 6 6 .______________
San Diego 1 6 __________________
__
Inchca 30.25 29.79 29.82
29.89 29.89 30.33 30.05 30.04 30.03
30. 20
normal
-
Date
0th. 17th. 19th.
29th. 28th.
4th. 10th. 11th.
aist.
aist.
1 P. m. observations only.
2 For 26 days. And on 28th.
4 For 30 days.
8 A. m. and p. m. observations.
6 Corrected to %hour mean.
Few, if any, months since our special studies of the weather of the North Pacific Ocean began have been so
generally stormy as was January, 1930, winds of storm to hurricane force in themselves occurring on at least 11,
and probably more, days. On the American-Hawaiian routes, though none of the deep cyclones characteristic
of more westerly areas occurred there, several active
depressions formed and the accompanyin gales of force
first 16 of the month. These were largely experienced some 10 to 20 degrees northeast of the islands, the fre-
quency lessening considerably thence toward the Cali- fornia coast. In the vicinity of Hawaii gales occurred on the 13th and 15th, being of force 10 from the northwest
in the lee of Oahu Island on the 13th. At Tatoosh Island, Wash., winds of force 11 were re 'stered at the Weather Bureau station on the 16th anf17th, and lesser high
velocities on several other days. Over the eastern part
of the ocean there were fewer days with gales on the upper than on the lower routes this month. The eastern-
most gales to attain hurricane force occurred on the 15th near the fiftieth parallel between 150° and 160° west
longitude. This was in the region of greatest pressure gradient between the Alaskan anticyclone and the ex-
tensive mid-Pacific cyclone of that date.
S to 10 were encountered on a t least 13 2 ays out of the
JANUARY, 1930 37
The area of most intense and longest-sustained storm
was embraced between latitudes 30' and 50' N., =f%q+tudes 170' W. and 155' E. Here the Aleutian
Low largely concentrated, and into this vast expanse of
depressed barometer poured the most of the moderate disturbances which originated in Asia and in Asiatic
waters. Here on no less than 10 days winds of major
intensity-force 11 to 12-were developed, beside whole gales on several days, and fresh to strong gales almost
daily throughout the month. Here also individual pres- sure readings were made a t times that were practically an inch lower than the minima of about 29 inches observed
at either Dutch Harbor or St. Paul in the heart of the
normal winter low pressure region. Between longitudes 180' and 170' W. winds of storm to hurricane force were
encountered on the 2d, 4th, loth, 13th, 16th, and 17th, and west of 180' on the Ist, 2d, 4th, 24th, 25th, and 30th.
The first four days of January formed an exceptionally
stormy period, the severe weather covering an immense area. From the 13th to 17th another period of sustained
severity occurred, this one irregularly affecting half the ocean, but concentrating its greatest energy between the
thirtieth and fortieth parallels north of Midway Island.
After the 25th the weather moderated in east longitudes, although on the 29th and 30th wind forces of 10 or 11
were reported from small areas at steaming distances of a day or two east of Japan. Strong northeast'monsoons of force 7 to 9 were reported
on several days along the entire China coast.
I n the Gulf of Tehuantepec northers of force 8 to 9 were reported by seamen on the 3d, 4th, 5th, 23d, 24th, 30th, and 31st. At the port of Salina Cruz Tehuante-
pecers of force 9 were reported on the 3d, and of force 10
on the 4th, 5th, loth, 23d, and 30th. The unwonted pressure alinement over the Pacific
caused the prevailing wind a t Honolulu to be from the
north for the first time on record for any month since
MONTHLY WEATHER REVIEW
CLIMATOLOGICAL TABLES
the establishment of the station in 1904. The maximum velocity was at the rate of 35 miles an hour from the south-
west on the 15th, during the prevalence of the low pressure wave which covered the greater part of the ocean.
Fog occurred on only two or three days over the western part of t,he ocean. Over the eastern part fo
scattered, but formed on three to five days in some ocali-
ties along the northern and central routes. On the coast of the United States there was a considerable
decrease from that of December, the occurrence off middle
California falling from about 50 to about 20 per cent, and from about 25 per cent to 10 or lower north and south of
this central coastal area.
5 "Bp
PAMPERO
The following account of a pampero which occurred on
January 1, 1930, at the mouth of the Parana River, Paraguay, was furnished to the Weather Bureau by
Mr. W. A. Farrell, second office.r and observer of the British t'anker Sun Macedonio, Capt. J . W. Tozer, Rio
de Janeiro to San Pedro, via Buenos Aires:
January 1, 1930, 4 p. in., civil time, whilst proceeding up the Parana River about 10 miles from where i t enters the River Plate, the sky was observed to be very heavy with thundershowers t o the west. Thunder and lightning were observed for one hour before the pampero struck the ship. The pilot advised all awnings to be taken in, and a t 4 p. m. with a rush and a roar from the SSE. the wind and rain came at hurricane force, i t being BO strong that i t steered the ship toward the weather bank of the river (this being a tanker with the funnel aft, the funnel acted as a sail and caught most of the wind above the trees). The engines were put full astern and the anchor let go, and the ship swung across the river head to wind, there being plenty of room at this part of the stream. It continued to blow for quarter of an hour with the temperature a t 6 6 O , which was a drop of 22' in as many minutes, the barometer remaining steady at 29.52. The wind then eased off, and the barometer slowly rose, but fairly heavy rain continued until midnight. Through the
rain was seen a glorious orange sunset low down on the horizon. By morning the sky was perfectly clear and the barometer had risen to 29.60, the ship being now with an ESE. breeze, force 4.-V. E. H
DESCRIPTION OF TABLES AND CHARTS
Table 1 gives the data ordinarily needed for climntologi-
cal studies for about 184 Weather Bureau stations mRking
simultaneous observations a t S a. m. and 8 p. 111. daily, seventy-fifth meridian time, and for about 31 others
making only one observation. The altitudes of the in- struments above ground are also given.
Beginning January 1, 1928, movement and velocity of the wind are printed as recorded by the 3-cup anemom-
eter which has replaced the 4-cup pattern.
Table 2 gives, for about 37 stations of the Canadian
Meteorological Service, the means of pressure and temperature, total precipitation, depth of snowfall, and
the respective departures from normal values except in
the case of snowfall. The sea-level pressures hrtve been computed according to the method described by Prof.
F. H. Bigelow in the REVIEW of January, 1902,30: 13-16.
CHART 1.-Temperature departures.-This chart pre-
sents the departures of the monthly mean surface temper- atures from the monthly normals. The shaded portions
of the chart indicate areas of positive departures and
unshaded portions indicate areas of negative departures. Generalized lines connect places having approsimat ely
equal departures of like sign. This chart of monthly
surface temperature departures in the United States was first published in the MONTHLY WEATHER REVIEW
for July, 1909, but smaller charts appear in W. B. Bul-
1 h n TJ for 1873 to June. 1909. inclusive.
CHART 11.-Tmcks qf centers of ANTICYCLONES; and
CHART III.-Trclcks of centers of CYCLONES. The Roman numerals show the chronological order of the
centers. The figures within the circles show the days
of the month; the letters a and p indicate, respectively, the observations at 8 a. m. and 8 p. m., seventy-fifth
meridian time. Within each circle is also given (Chart 11), the last three figures of the highest barometric
rending, or (Chart 111) the lowest reading reported at or near the center at that time, in both cases as reduced
to sea level and standard gravity. The inset map of Chart I1 shows the departure of monthly mean pressure from normal and the inset of Chart 111 shows the change
in mean pressure from the preceding month.
The use of a new base map for Charts I1 and I11 is begun with thisissue. Instead of showing the 12-hour move-
ment of cyclones and anticyclones, only the 24hour move-
ment is shown. CHART IV.--Percentage of clear sky between sunrise and gun- set.-The average cloudiness a t each Weather Bureau station is determined by numerous personal observations between
suniise and sunset. The difference between the observed cloudiness and 100 is assumed to represent the percentage of clear sky, and the values thus obtained are the basis of
this chart.
CHART V.-Total precipitation.-The scales of shading with appropriate lines show the distribution of the
monthly precipitation according to reports from both
regular and cooperative observers. The inset on this
The chart does not relate to the nighttime.