MONTHLY WEATHER REVIEW Editor, EDGAR W. WOOLARD
CLOSED J n N I ? 3, 1935
APRIL 1938 IAAUED JULY 1938 VOL. 66, No. 4 W. B. No. 12%
REPORT ON THE WEATHER BUREAU RADIOMETEOROGRAPH PROGRAM
Ry L. T. S\hlUELS
[Weather Burem. W:t4iington, D. C.1
Remwkable progress l m been iiiadc~ in tllis country
during the past 2 years in the development of radio- meteorograplis ; a t least 5 different types have been
developed. In January 1937, wlien it was necessary for tlie Weather Bureau to decide on its program for tlie
fiscal year beginning July 1, 1937, no one type had been sufficiently developed for regular use in scheduled observa-
tions. It was, therefore, deeiiiecl best to continue the
study of all 5 types in order to explore more thororigldy the best features of each.
A t the Central Office of the Weather Bureau in W'nsh- ington. all of the various types uf ratlioriieteorogrnplis are
being used in an attempt to develop the niost suitable calibration and receiving apptrc:tus, evaliiat8ion nietilods,
Inunching teclinique, etc. A specialist in rdometeor-
ogrnphy has recently been acldecl to the Central Office staff for this purpose.
The designers of tlie 5 types are: (1) H. Diamond and
W. S. Hinman, Jr., and their collaborators of the National
Bureau of Standards in cooperation with the Navy De- partment and Jdien P. Friez and Sons, Inc.; (2) L. F. Curtiss and A. V. Astin of the National Bureau of Stantl-
arcls in cooperation with the Weather Bureau; (3) 0. C.
Maier and L. E. Wood of the California Institute of Technology; (4) I<. 0. Lange, A. E. Bent, and C. R. Pear,
Jr., of Blue Hill Observatory, IIarvard University; and
(5 ) the Weather Bureau in cooperation with Julien P. Friez and Sons, Inc., Bdtiniore, Md.
Development was continued by Dianioncl and his col-
laborators on their instrument; and the Weather Bureau, again this fiscal year, transferred a suiii of money to the National Bureau of Stnndarcls for continuing the develop-
ment of the Curtiss and Astin type. With regard to the
other three types of radiometeorogr,zplis, tlie Wentlicr Bureau set up a program hitving a twofolcl objective: to niaintain close contact between the nianufacturer and the
Weather Bureau personnel lnaliing tlie observations ; and
to operate a station far distant from the manufacturer. In accorclance with tlie program, daily radioiiieteor-
ograpli observations were begun a t the Weather Bureau Airport Station, Burbank, Calif., September 1, 1937, and
are to continue until June 30, 1938. The instruments
used there are known ns the Galcit type, developed a t tlie California Institute of Technology. These meteorographs
are calibrated by the contractor in Pasadena and are delivered to the Burbnnk station in small lots so that an
instrument is available each day. The soundings are
macle, as nearly as practicable, a t the same tinie as tlie airplane observations a t San Diego Naval Air Station so
that coinpnrisons of the data can be nisde. At the Boston Weather Bureau Airport Station, daily
radiometeorograph observations were begun October 1,
1937, mcl are to continue until June 30, 1938. The
72679-301
IIarrarcl type instrument ileveloped a t Blue Hill Obser-
va tory, is being used t h e . While close contitct bet,ween tlia Bureau personnel nncl tlie contractor in Cambridge,
RI:iss., is also possible at Boston, the :irr:iiigeiiients t,liere require the instruiiients to be calibrutetl by t,iie Weather
Bureau iiisteatl of by the contractor. This procedure was
adopted in order to determine wliicli plnn might prove best for future policy. Prior t80 the discontinunrice of t8he
Army airplme observat8ions a t Boston on Dcieiiiber 3 1 ,
1937, the r:dio soundings were mncle at the saixie time for
conipitrison . In connection with an investigation of tlie qtructure ol
polar contiiiontnl air and the developnieiit of cold wares
in North Aniericii, authorized under the Uaiikliead-Jones Act, tlie FYe:i tlier Bureau macle dnily radioinctcorogmpli
observations a t F:iirbaiiks, A h l a , from October 7, 1937, to March 15, 193s. The instruments used there are known
as tlie Weatlier Bureau type and are manufactured in Baltimore. They were shipped in nionthly lots to Fair-
banks, where they mere calibrated by Bureau personnel.
Under this plm, the practicability of transporting the instruments long distsnc,es and of using them under severe
weather conditions was studied. Airplane observations
were made a t Fairbanks every third day during this period
for comparison with tlie radiometeorograph data. The observations are prninptly evduitted and data for
tlie iiieteorologically significnnt levels trnnsriiitted by radio to Washington, and to other stations, where they
nre charted and analyzed in coiijunc tioii with tlie regular a ervlogical reports.
During the first 132-clay period a t Burbank, 97 radio meteorograph records were obtniiied ; of these, S i percent
exceeded 5 kni, 42 exceeded 10 km, and 13 esceeded 15 km.
The maximum heidit attained at Burbank was 19.5 km. During tlie first 92-day period ut Boston, 77 raclio-
meteorograph records were obtained; of these S7percent es-
ceeded 5 h i , 25 exceeded 10 kin, and 4 esceecled 15 km. The rnasiiiiuiii height attained nt Boston, was 22.2 kin.
During the first SG-clay period a t Fairbanks, 60 radio-
meteorogrnph records were obtained; of these, 75 percent exceeded 5 kin, 13 exceeded 10 h i , nncl none reached
15 lim. The niaxhiiuni height attained a t Fairbanks was 12.9 kni.
In table 1 itre sliown the percentages obtained for
differences of the temperatures indicated by the mdio- nieteorograpl!s froin those shown by tlie nirpiane observa- tions at the sigriificaiit levels for the period of observation
eiicling December 31, 1037. Becsiuse of tlie distmce
bet\$ een Burbank and S:in Diego, the data below 1 krn a t these 2 stations were not iiiclucletl in this comparison.
The figures in the upper left corners of tlie first colunins for each station iiiilicat,e the total number of cases on which
the percentages are bosecl.
93
94 MONTHLY WEATHER REVIEW APRIL 1938
surface temperature is indicated and each abscissa interval
corresponds to loo C. The numbers adjacent to the
TABLE 1
1 Burbank 1 Boston 1 Fairbanks curves are relabive humidities.
September---.-.
October. - - - - - - -
November---.-.
December-.---.
Total-.--.
0'10
65
116
107
139
35
35
31
27
32 427
LO-20
25
22
22
30
I n table 2 are shown the percentages obtained for a
comparison of relative humidities using the same method as for temperature. Humidity comparisons were made
for temperatures above 0' C. only as well as for all
>20 00-10 10-20 >20 - 00-10 10-20 >a0
--------
40 __________ ______ ____._ __________ ______ ._____
43 21 25 54 37 11 52
47 45 26 29 39 10 51
43 37 m 35 26 24 50
178 48
173 39
1% 58
temperatures.
63
147
41 Above 0" C ___________________ 38 24 10 7 137
All temperatures _____._______ 34 22 1 G 6 4 75 0 25 0 Above 0' C __.________________
Above 0' C _________________._ 41 29 s 11
All temperatures _____________ 34 23 17 15
October:
November:
December:
im All temperatures ____________. 29 14 18 9
A11 temperatures _______ 32 20 17 10
108
401
6 Total: 52 18 14 Above 0' C _____________
September: Above 0" C __________________
3 S
3 S
5 15
9 13
0 0
8 ?:!
3 7
7 14
All temperatures- __------- -- October: Above 0' C __________________
October: 15
34
November: 0
Above 0' C __________________- 20 20 20 20
All temperatures _____________ 18 23 20 18
All temperatures _____________ 50 14 19 6
Above 0' C ___________________ __________ ________ ________ ____.___
36
1
0 0 0 0 Above 0' C __________________- 39 All temperatures _____________ 38 28 10 13 16
109
December:
Total: Above 0' C _____________ 10 10 10 10
All temperatures _______ 36 22 16 .13
All temperatures _______-----
Above Oo C __________________
November:
1 13
9 12
________ ________
3 8
1M) 0
3 8
7
5 9
53
All temperatures- - - - _____ __-
Above 0' C __________________
December:
All temperatures _____________
Above 0' C ________----
All temperatures.-- ___
Total:
TABLE 2
BURBANK
58
68
s3
113
72
106
81
141
294
4%
31
31
35
34
28
28
28
7.6
31
30
33
34
22
19
28
24
28
26
27
28
24
24
18
11
22
23
17
16
19
1s
-
620%
7
l G 7
19
12
12
9
11
11
12
&25%
-
5
4
9
10
3
5
9
S
6
7
>'I&"
-
0
0
6
7
7
8
11 13
G
7
BOSTON
FIGURE 1.
600 544 5.48 613 859 RAOB TIYE 547 5.47 544 7:OO 6:03 621 724 6'10 APOB 6:19 64.5 636 DAY 14 -' I5 17 20 2.l 29 28 31
FIGURE 2.
-10 -10 IO -20 -20 RAOB TIMEpm. 200 200 300 200 4:OO
APOB 2:oo 2:oo 200 200 4:oo ' DAY 14 IS 20 24 26
FIQWE 3.
Before conclusions can be drawn from these results,
however, a number of factors must be taken mto account.
APRIL 1938 MONTHLY WEATHER REVIEW 95
These include: differences in the paths followed by the air-
plane and the balloon and therefore possibly even different
air masses encountered ; the limited experience of persomiel
in the technique of calibrating and of mnking regularly scheduled observations of this kind; differences in time,
in some cases, between the airplane and radiometeoro-
graph observations; diiferences in rate of ascent and lag of
radiometeorograph and aerometeorograph ; possible changes in the aerometeorograph since last calibration; and possible
differences between the initial temperatures of the instru-
ments. It is planned in the near future to obtain comparisons by
sending aloft the vnrious types of radiometeorographs
simultaneously from the smie place, ulth recording, i. e.,
nonradio, meteorographs attached to the same balloon. This method of comparison is considered to be more re- lidble than the airplane observations used so far. In view of the promising results being obtained with
radiometeorographs and because of the great value of the observationnl data, it is planned to increase the number of stations to six next fiscal year. To do this, it will be
necessary to re,place airplane with radiometeorogrnph
observations a t some place,s, since additional funds were not made avnilable for this work. An important factor
in this connection, which should reduce the cost materially
a t favorably located stations, is the large percentage of
instruments which will be found and returned. The per- centages of recovery for some of the past sounding balloon series made in this country wit,h recording meteorographs,
i. e., the nonradio types, are given in table 3.
TABLE 3
Piace
93
Q4 91
83
91
84
76
Q2
65
With the experience which will be gained during the next fiscal year, it seems probable that inost of the airplnne
observations d l be replnced by rntliometeorographs after --
June 1939. It is desired to acknowledge the assistance of R.I. E. Crawford of the Aerological- Division for drawing the
graphs shown.
RECORD-BREAKING ANNUAL PRECIPITATION, 1846-1850
By LEON J. GUTHRIE
[Weather Bureau, Dayton, Ohio]
Available records for the yenrs of 1846 to 1850 establish
the fact thnt over limited nreas of northeastern United States remarkably heavy annual precipitation must hnve
occurred. For instance, southwestern Ohio experienced
wetness that has never been approached since that tirye; a peak of 63.96 inches was recorded a t Dayton durmg 1846 ancl 65.18 inches n t Cincinnati during 1847. Cor-
respondingly heavy precipitation apparently fell a t points
as far west ns St. Louis, where 65.36 inches were recorded during 1848. A curious feature is the time lag of a year
between the maxiniuin amounts n t each of the three stations. The siiriilaritp of these maximum figures tend
to bear out tlie authenticity of the data, $though gagEs or methods of measurements might have differed materi- ally in those clays. At Steubenville, Ohio, it is also to be
noted that there was a surplus for which we find no equnl in later records of southeastern Ohio.
Judging by graphs of all the above stations, not only
did copious rains occur but the yearly variation was more erratic than it has ever been since. This condition lastecl
until about 1860; a t least one bad drought is evident
between 18.50 ancl 1860. It is interesting to note that
extreme positive departures for precipitation a t the above stations were never offset by negative depnrtures ?f equal or greater magnitude. One cnnnot reach any definite con-
clusions from the foregoing data because of the paucity of
records prior to that time nnd the fact that nenrby stations disagree in some of the main characteristics. At Dayton the old record was-kept a t Coopers Sem-
inary, which is remembered as having had a good standard for education51 work. Originally this old part of the
record was omitted from precipitation charts as seemingly
doubtful, but more recent studies indicate that it should
be included. It is presented in the accompanying graph with missing years adapted from the Woodwnrcl High
School record a t Cincinnati. This is on the assumption thnt it gives a genernl idea of the trend for the missing
years ; the normal annual difference be tween Dayton and Cincinnati is only 0.69 inch.
The extremely wet years were preceded and followed by
subnormal rains in 1845 niid in 1851; thus, rain diagrams show a shttrply defined positive area for the intervening
years. At St. Louis precipitation decreased considerably after 1848 but increased again to the all time maximum of
6S.S inches in 1858. In eastern Ohio, and as far east as
Pittsburgh, the ye:m 184G to 1850 reveal similar charac-
teristics for precipitation except that the nmounts nre not nearly as excessive as in southwestern Ohio. Annual fluc- tuations were more marked subsequent to the early years
mentioned and down to the year 1890. To the south, Springdale, Kentucky, showed an average excess for the
period 1846 to 1850 of 5.33 inches. Much farther south, a t New Orlenns, rain was below normal within the wet
interval, while as far east as Rochester, N. Y., it was just slightly in excess.
The above figures would serve to uphold the tradition tlint it doesnt rain like it used to, a t least for a few
sections in the Northeastern States. For sout,hwestern
Ohio it looks as if bnck in the years 18.16 to 1850 rain making forces within the atmosphere reached their
maximum of recorded history. Annual amounts of 56
inches or more appear in the records as late as the year
1890, but after that they are exceeding rnre. The mcom- panying graphs of precipitntion a t Dayton, Cincinnati,
and St. Louis were taken from the Climatic Summary
of the United States, 1930 edition.