Page 309

Section 3: Weather and Communications

Page 310

Blank page

Page 311

Chapter 11: The AAF Weather Service

Just as a ground commander must know the terrain over which his troops and supplies move, so did the successful air commander of World War II depend upon uninterrupted and fresh intelligence regarding the atmospheric “terrain” in which his forces operated. The vertical dimension of his three-dimensional battlefield was no less significant than its length and breadth. Atmospheric conditions thousands of feet above the ground determined the pathways open to his aircraft, and weather hundreds of miles away could be of greater military significance than a storm over his own headquarters. For this indispensable information the air commander relied on the delicate instruments and skilled personnel of his weather services. By the end of the war those services had come almost to be taken for granted, so much so that little thought was any longer given to the near-miracle they represented.1

When the war began, modern meteorology, with its special dependence for the purposes of weather forecasting upon analytical study of the movement of air masses, was still a youthful branch of scientific investigation. Its principles and techniques had been developed first by the Scandinavians as a result of having been shut off from customary weather intelligence by the combatant powers in the first World War. The new approach began to influence meteorological studies in American universities and technical institutes only in the later years of the 1920’s, just in time to serve the needs of a rapidly growing commercial air transport system. Systematic and scientific weather reporting was still limited very largely to the European and North American segments of the globe, and wartime interruptions of normal opportunities for communication promised increased difficulty in efforts to extend adequate weather services into more than one strategically

Page 312

critical area. The general tendency for weather to move from west to east, together with the prospect that the Americans would enjoy the full assistance of Britain’s well-developed weather services, promised an advantage over the enemy in Europe. On the other side of the globe, the Japanese had the advantage. The swift and sweeping southward advance of their forces after Pearl Harbor closed to all Allied reporting a vast area of major significance to weather in the Pacific Ocean. On the mainland of Asia, China and India remained in friendly hands, but the weather data that could be secured from those territories obviously would depend very greatly upon such services as could be developed by the Allied armed forces. Similarly, along the more critical of the new air routes, including those across the Atlantic, the facilities for both collecting and disseminating information on weather had to be developed along with the routes themselves.

Although weather could significantly affect a variety of military operations and was especially important to the success of an amphibious landing, weather had its greatest continuing importance for air operations. The Japanese took advantage of bad weather in the mid- Pacific to screen their approach to Pearl Harbor in December 1941. Some fifteen months later, a miscalculation in the Bismarck Sea cost them dearly, when the storm under whose cover their convoy sought to reinforce Lae in New Guinea dissipated, and the Fifth Air Force won a major victory.* On the other side of the world, the heavy concentration of enemy fighters encountered by the Eighth Air Force attacking Schweinfurt on 14 October 1943 was a direct result of accurate forecasting by the German weather services. Because this target lay in the only part of Germany in which daylight bombing seemed to be possible under prevailing weather conditions, the Germans massed their fighters in such a way as to inflict on the Eighth Air Force the highest percentage of loss it had suffered to date.† To take but one other example from tactical operations, the weather forecast determined the timing of the “Big Week” of AAF bombing over Europe in February 1944.‡ Meanwhile, the ferrying of aircraft and the increasingly important development of air transport services depended fundamentally upon the growing military weather services, which became in time quite literally world-encircling.

* See Vol. IV, pp. 141-46.

† See Vol. II, pp. 699-704.

‡ See Vol. III, p. 31 ff.

Page 313

The AAF Weather Service

On the eve of war the U.S. Weather Bureau maintained a modern and efficient system of weather reporting for the continental United States. Although many facets of American life had come to rely on the regular and increasingly dependable reports of this service, the most important of recent developments in the Bureau’s activities had been undertaken in the interest of commercial aviation. Across the country, in thirteen districts, forecast centers were maintained at key airports to provide for pilots route forecasts that added greatly to the safety of aircraft flights, both civil and military. The Army, in whose interest the federal government had first undertaken the development of a weather service, depended also upon a supplementary organization of its own embracing some thirty weather stations in the United States and another half-dozen located in overseas possessions.2 The responsibility for equipping and manning these stations belonged originally to the Signal Corps, but most of them were operated for the special benefit of the Air Corps. Accordingly, the War Department in 1937 had reassigned the responsibility for operation and control of these stations to the Chief of the Air Corps.3 The Signal Corps continued to be responsible for the development, procurement, storage, and issue of meteorological equipment until late in 1945. Coast and field artillery, ordnance, and chemical warfare units might provide for themselves weather facilities peculiar to their needs, but the Air Corps, as chief user, now took over the primary obligation for meeting the Army’s need for special weather services.4

As war became imminent, the original plans for expansion of the AAF’s weather services were extremely modest. Personnel needs fell into two general categories: (1) men sufficiently trained to serve as forecasters and (2) those who had the skill to serve as observers for the collection of data pertinent to exact forecasting. Standards for recruitment were high. Not only did the performance of these tasks demand a high order of intelligence and some background in mathematics and physics but also policy gave preference in the training of forecasters to officers who were experienced pilots. Especially qualified pilots who applied for the training were sent at the rate of eight each year to study at the Massachusetts Institute of Technology and the California Institute of Technology. In September 1937 a special school was opened at Patterson Field for the training of enlisted men

Page 314

as forecasters in a six-month course. Approximately fifty men were graduated each year. Observers at first received their training on the job at AAF weather stations. In September 1939 a special school for observers was established at Scott Field, with an entering class of seven men who were committed to a three-month course of study.5 Early in the next year the two schools were moved to Chanute Field and incorporated into the Air Corps Technical School.

By the summer of 1940, when France fell and the fate of England hung on the Battle of Britain, it became apparent that all previous planning for the weather services fell far short of the need. In July a special committee representing the Weather Bureau, the Army, and the Navy reported an inventory of qualified forecasters in the nation distributed as follows: the Weather Bureau, 150; civil airlines, 94; Army, 62; Navy, 46; educational and other institutions, 25. Immediate requirements for increases in these numbers showed for the Army 175, for the Navy 80, and for the Weather Bureau from 25 to 30. It was recommended that the government seek the co-operation of universities offering suitable programs in meteorology as the best way to meet these deficiencies.6

Negotiations for this purpose already had been opened with the Massachusetts Institute of Technology, the California Institute of Technology, the University of California at Los Angeles, New York University, and the University of Chicago, all of which had well-established programs of study in meteorology. An original plan for the Air Corps to enroll 40 students in these institutions was modified by the end of August, at General Arnold’s insistence, to provide for a total of 150. Recruitment of qualified applicants was to be pressed among “washouts” from pilot training and among students in educational institutions on a promise of training in cadet status. Additional help in the event of war was expected from a program, inaugurated simultaneously under the leadership of the Weather Bureau and the sponsorship of the Civilian Pilots Training Program, for the training of an additional 100 meteorologists. By October 1940, the Air Corps had almost 150 recruits launched on a nine-month course of study at one or another of the participating universities.7 The members of the first class had been assigned to duty several months before Pearl Harbor, and the second class of 180 had been in school long enough to be graduated in February 1942, six weeks ahead of schedule.

Page 315

This addition gave the AAF some 330 trained weather officers, but it was now estimated that total needs would be 1,000. By downward adjustment of educational standards for recruitment and with the aid to recruitment that came from the outbreak of war, the AAF entered 440 cadet students in March and another 400 in September. By that time the estimated requirement for weather officers had jumped to 4,000, and at the end of the year, as plans for a 273-group air force became firm, the goal had been placed at 10,000 weather officers by 1 January 1945.8 The hope of meeting any such goal as this depended upon finding some solution to the problem of recruitment. Because of the special educational qualifications that were required for advanced meteorological training, this problem had been considered acute almost from the beginning of the program. Recruitment by other services and the drafting of young men at the age of eighteen promised that the supply of candidates having the academic prerequisites for study of meteorology would soon be exhausted. Accordingly, the AAF entered into agreements with some twenty additional universities and colleges for the inauguration in 1943 of an elaborate program of premeteorological training. Enlistment of applicants in an enlisted-reserve status was intended to assure protection of the students from the draft until they were qualified for admission to cadet status.9 The plan, after some opposition in the Air Staff, was approved in November 1942.

Unhappily, the whole program rested upon a gross overestimate of actual needs. How gross was soon made apparent to Maj. Gen. Barney M. Giles, Assistant Chief of Air Staff, Operations, Commitments and Requirements (OC&R), who in May 1943 insisted that by the end of that year the AAF would have enough weather officers to meet all its needs through 1944. The estimated number, counting in the graduates of December 1943, was 4,500 – less than half the total called for in existing programs.10 This estimate of needs did not take into account the possibility of expanded requirements in 1945, but experience proved it to be a far more accurate figure than any which had been used for planning since the earlier days of the war emergency. After a good deal of discussion, it was decided that the class entering upon advanced training in October 1943 would be the last. Even so, the AAF trained many more weather officers than it needed. Of the approximately 6,200 who were trained, over 1,800 were assigned to other duties.11 The inexperience of staff officers in a

Page 316

new area of military activity, miscalculation as to the most effective organization of weather services in combat zones,* the keen competition for especially qualified personnel during the hasty upbuilding of the armed forces, and the extraordinary size and complexity of the AAF’s total expansion-these and other factors contributed to this costly blunder. In looking back, it may be well to recall the psychology of the first months of war. A weather officer responding to General Giles’s criticism of the program in 1943 could insist, quite seriously and with some impunity, that wars were lost through shortages, not overages.

Whatever else may be said about the AAF’s meteorological training program, it promptly met the needs of a rapidly expanded weather service. After the transfer of responsibility from the Signal Corps, a Meteorological Section had been established in the Office of the Chief of Air Corps. The United States was divided into three (later four) weather regions, in each of which was stationed a meteorological squadron broken down into such detachments as were required to man its several stations. For administrative purposes the squadrons functioned under a group headquarters located at Bolling Field, Washington, D.C. As the service developed, weather stations of different types were taken over from the Signal Corps or were organized to meet new requirements in an expanding Air Corps. Some of these, as at major air bases, provided forecasting services through 24 hours each day. Others maintained regular observing services and provided forecasts as required. Still others functioned only for the purpose of accumulating data on the weather pertinent to the forecasting operations of other stations. The allotment of personnel to each station varied greatly and according to need. At major installations a station weather officer was in charge. At others a noncommissioned officer as station chief bore the responsibility.12 By the time of Pearl Harbor the service could boast a personnel roster of 4,300 officers and men.13

The pattern of organization developed for the Zone of the Interior had been extended overseas by a TAG letter of 18 November 1941 .14 Weather detachments in the Philippines, the Caribbean, Hawaii, and the North Atlantic were redesignated, respectively, as the 5th, 6th, 7th, and 8th Weather Squadrons and were given control of all

* It had been assumed, for example, that weather officers would have to be assigned at squadron levels, but experience later argued against this practice.

Launching a weather 
balloon – Marianas Islands

Launching a weather balloon – Marianas Islands

Reading meteorological 
instruments

Reading meteorological instruments

Theodolite operator, 
Greenland Base

Theodolite operator, Greenland Base

Page 317

weather activity in their respective regions. The squadron commander in each region thus became, as was the practice in the continental US., the regional control officer. To provide better services along the increasingly busy South Atlantic air route, a ninth region and squadron were activated in July 1942. A 10th Weather Region, embracing India, Burma, and China, had been established in the previous month, and the 11th had been created in May 1942 for Alaska, where the AAF shared responsibility with the Weather Bureau, the Civil Aeronautics Administration, and the Navy for observation and forecasting in an especially difficult area. The 12th Weather Squadron assumed the responsibility for serving the Twelfth Air Force in Northwest Africa late in 1942. And so it went. By the end of 1942 a total of nineteen regions had been established.15 This number was subsequently increased and regional boundaries were redrawn as experience seemed to require. By the spring of 1945 the AAF was operating all told some 900 weather stations, of which more than 600 lay outside the continental United States.16

Problems of liaison and control were many and varied. A Defense Meteorological Committee, representing the Weather Bureau, the Army, and the Navy, functioned from as early as the summer of 1940 to co-ordinate civil and military programs. Later, in 1942, this committee found formal place in the developing organization of the Joint Chiefs of Staff as the Joint Meteorological Committee. Under the Combined Chiefs a Combined Meteorological Committee effected necessary liaison with our British ally on such matters as the exchange of weather information, security regulations, codes, and avoidance of unnecessary duplication of services. After the liberation of France, the rehabilitation of French weather services and co-ordination of their activities with the then well-established Allied services paid good dividends. Less successful were efforts to win the co-operation of our Russian ally, although the Russian attitude relented somewhat after 1943. In North America and in the South and Southwest Pacific cooperation with the Canadians, Australians, and New Zealanders was close and effective. Typical of such co-operation was the establishment of jointly administered regional weather controls, stations organized and equipped for meteorological study and forecast for a large geographical area.17

More difficult were questions involving command relations within the Army and even within the air arm itself. From the beginning,

Page 318

experienced weather officers in the Air Corps recognized the central importance of developing a well-integrated and unified service. But the very dichotomy which marked the organization of the Air Corps after the establishment of the GHQ Air Force in 1935 brought up troublesome questions. The obligation to organize, train, and equip weather units belonged to the Office, Chief of Air Corps (OCAC), but the GHQ Air Force, as the combat organization of the Air Corps, controlled bases and tactical units to which weather personnel were assigned. What control over the operations of widely dispersed weather units could OCAC exercise in the interest of common procedures and an indispensable exchange of serviced And what influence could GHQ Air Force properly have over the development of doctrines and policies which molded the weather units assigned to its command? These were questions already familiar in more than one department of the Air Corps’ activity.* Some aid to their solution came with the decision in 1939 to make the Commanding General, GHQ Air Force, subject to the “supervision” of the Chief of the Air Corps and from the establishment of the AAF in June 1941, when the Combat Command, successor to the GHQ Force, was made subordinate to the Chief of the AAF.† Help was also found in the concept of technical supervision, through which a headquarters not having command over a particular unit might prescribe common procedures for all such units in “technical” matters.‡ More or less successful efforts were also made to protect especially trained personnel from assignments, including temporary ones, that were wasteful of their special skills. But the problem lingered on until the abolition of the Combat Command in the reorganization of March 1942.18

Thereafter, the more important of such issues involved units assigned to overseas theaters. Traditionally, the prerogative of the theater commander in a combat zone was inviolable, and yet the effective operation of a world-wide weather service necessarily required a measure of centralized supervision and control. Weather units committed to overseas service were assigned originally to the several theaters or area commands, with no reservation other than

* See, for example, Vol. I, p. 32; and Vol. VI, p. 364.

† See Vol. VI, pp. 11-35, for a study of organizational developments from 1939 to 1942.

‡ In an amendment to AAF Regulation 105-2 of 3 February 1944, technical supervision was for the first time officially defined for the weather service as that “normally exercised through technical orders and specifications necessary for the control and supervision of operating procedures peculiar to the AAF Weather Service.”

Page 319

that of technical supervision by the appropriate AAF agency. There were a variety of ways in which the AAF could exert a helpful influence. It could secure by negotiation protective clauses in War Department Regulations that were in some particulars binding on all theater commanders. The growing autonomy of the AAF as a service having separate representation on agencies of the Joint and Combined Chiefs of Staff provided other and helpful channels of influence. Nevertheless, the problem found no clean-cut resolution until virtually the end of the war.

Part of the difficulty lay in the inability of the AAF to settle certain of its own internal problems of organization.19 In the reorganization of March 1942 the responsibilities of the earlier Weather Section devolved upon the Director of Technical Services, in whose office at AAF Headquarters was established a Directorate of Weather, The new Director of Weather, Col. Don Z. Zimmerman, within a few months had taken significant steps toward integrating all weather personnel and units within the United States into an organization directly responsible to the directorate. Base units and tactical units theretofore belonging to the Combat Command were transferred to the control of one or another of the four weather regions. Some thought had been given before March 1942 to the creation of a separate weather command, but one of the principles on which the reorganization of that month rested was a belief that AAF Headquarters could function for both the shaping of policy and the direction of operations. This belief, however, was soon abandoned. The policy governing another reorganization, effective in March 1943, was to get operations out of Washington. Consequently, the directorates were abolished, and responsibility for direct supervision of the AAF Weather Service (so designated in 1942) was transferred to the newly created Flight Control Command with headquarters in Winston-Salem, North Carolina. For the exercise of this responsibility, the command activated the Weather Wing on 14 April 1943 and soon thereafter located the wing’s headquarters in Asheville, North Carolina.20

In July 1943 the Weather Wing became an independent unit by its reassignment to the direct control of AAF Headquarters, where a newly created Weather Division in OC&R assumed supervisory responsibility for the AAF Weather Service.21 The Weather Wing at Asheville controlled all weather units assigned to the AAF but

Page 320

had no authority over units assigned to combat theaters except for the technical control it exercised over certain procedures. Through the next two years there was much discussion of the organizational and jurisdictional problems presented by these arrangements, and, finally, in July 1945, a thoroughgoing reorganization was begun. The Weather Wing became Headquarters, AAF Weather Service (AAFWS) ; the Weather Division was abolished and its personnel assigned to Headquarters, AAFWS, at Asheville; a new Chief of the AAF Weather Service, with office in Washington, was made directly responsible to General Arnold and would serve as Arnold’s top adviser on all questions relating to weather service. The concept was one already adopted in the fields of air transport and air communications: to concentrate full responsibility in a single command and to give to it operational control of all pertinent services. As the war came to an end a few weeks later, action had been begun for the reassignment of weather units throughout the world to the operational control of the new command.22

Operations – Europe, Africa, the Far East

The most impressive achievement of the AAF Weather Service was the extension of its vital activity overseas. That story falls naturally into two parts: (1) the extension of weather services eastward across the Atlantic to battle stations in Europe and Africa and thence across the Middle East to India, Burma, and China and (2) the extension of these same services westward from the United States across the Pacific.

Early flights along the South Atlantic air route depended very largely for weather intelligence upon the meteorologists of Panair do Brasil, subsidiary of Pan American Airways. During 1941 the AAF activated nine weather stations in Puerto Rico, Panama, the Canal Zone, British Guiana, the Virgin Islands, and the British West Indies. But when war came, just after the establishment of the 6th Weather Region,* the AAF still operated a very incomplete service, and shortages of equipment and personnel continued for several months thereafter to plague responsible officers. Local training of edited forecasters at Albrook Field in the Canal Zone provided some help in meeting the shortage of personnel. Gradually, needed equipment came through, and the creation of a 9th Weather Region in

* See above, p. 316.

Page 321

July 1942 helped to solve administrative problems attendant upon an expanding service to ATC and tactical units flying out by way of Brazil to Africa, the Middle East, and the Far East.23

The first American weather personnel to serve along the North Atlantic airways arrived at Gander Field, Newfoundland, on 9 March 1941, to support the 21st Reconnaissance Squadron, then on antisubmarine patrol. Three weather officers and ten enlisted men worked alongside Canadian personnel and used Canadian facilities until American equipment became available. Within two months they were turning out synoptic maps of the North Atlantic. With American occupation of the Atlantic steppingstones and the development of an air ferry and transport route to Great Britain, Gander Field ultimately became the nucleus of a weather net that reached from North America to the British Isles.24

The many Atlantic storms originating in the Far North underscored the need for timely and reliable weather data from northern Canada and Greenland. To help fill this gap, six enlisted men accompanied the United States Marine Corps task force that landed at Narsarssuak (BLUIE WEST 1) on 6 July 1941 to assume protective custody of Greenland. Their mission was to establish a weather station and support flight operations at the air base to be built there. Three months later a weather detachment arrived at BLUIE WEST 8, on Greenland’s west coast just above the Arctic Circle. This station provided a strategically located post for the observation of air masses moving out of the polar region. Before the end of the year, the third Greenland weather installation was established at BLUIE EAST 2, near Angmagssalik, on the east side of the big island. Danish stations in Greenland, with new American radio and meteorological equipment, became integral parts of the AAF weather net.25

In the meantime, on 1 September 1941, an air weather detachment of seven men which landed with the first American task force in Iceland had started operations at Reykjavik. For several weeks weather data available there were meager, even when they included reports secured by walking to the British station a mile away or by rowing out to an American destroyer in the harbor. Fortunately, the demand for weather services in Iceland did not become pressing until the great increase in air traffic over the North Atlantic route in the summer of 1942.26

The three Crystal stations, in northern Quebec and on Baffin and

Page 322

Padloping islands, were favorably located to observe the movement of polar air masses.* If and when the projected Crimson Route from western Canada across Hudson Bay to Greenland were opened, these Crystal stations would be needed to support flight operations.27 This completed the growing roster of weather installations in or near the North Atlantic at the end of 1941. Weather and communications from Iceland to the British Isles remained a British responsibility.

Approximately fifty American weather officers and men were on duty in the north. In effect, each station provided a more or less independent forecasting service tailored to meet the needs of an individual base. At best, such a disunited weather service could be of but limited value to users of a transoceanic ferrying and transport route. Forecasters still drew weather maps on the basis of data they knew to be almost fragmentary. But, gradually, the more serious gaps in the weather-reporting net were filled by the opening of new stations and the improvement of communications facilities. The Azores were included in 1943 with the opening of the station at Lagens.28

Men assigned to the lonely and rugged North Atlantic weather stations had to be hand-picked for emotional stability and physical stamina. Those who pioneered BLUIE WEST 8 had no contact with the outside world, except by radio, from the departure of the last surface vessel in December 1941 until the arrival of the first aircraft on the newly built airfield four months later. Men at other northern stations endured comparable intervals between mail calls. Stations at Mecatina and Indian House Lake, in Quebec, were completely inaccessible by land and water and had to be established and supplied wholly by air. Subzero weather and high winds played havoc with housing and with equipment designed for use in more temperate climates. But there were compensations. Wild game occasionally offered welcome variation of diet. The men were kept busy and so physically fit. At BLUIE WEST 8 the commanding officer taught his men to ski. Almost everywhere, morale was reported good.29

To assist fighter aircraft headed for the British Isles as part of the BOLERO movement in the summer of 1942, weather reconnaissance flights were first tried. Experience emphasized the desirability of a regular weather reconnaissance program to support all air traffic, and by 1943 three B-25 type aircraft shuttled between Presque Isle, Goose Bay, and Gander on weather flights, while three B-17’s based in Newfoundland

* See above, pp. 93-94.

Page 323

provided coverage from 500 to 800 miles eastward over the Atlantic.* Beginning in January 1944, three specially equipped C-54’s flew between North American bases and the British Isles, to fill the mid-ocean gap where storms could maintain themselves without revealing their behavior. Each C-54 carried two weather officers specially trained to observe weather from the air. The aircraft generally flew directly across the Atlantic but might return to the United States by way of Iceland or Greenland or along North African–Azores routes if necessary because of bad weather. Qualified observers also made in-flight observations from regularly scheduled C-54’s crossing the Atlantic. Navy and Coast Guard vessels stationed along the airways provided additional coverage at surface level.30

Aerial reconnaissance as a regular feature of operations along the southeastern route did not start until the spring of 1943. Forecasters carried on Air Transport command flights in both directions between Atkinson Field, in British Guiana, and Belém transmitted on-the-spot weather reports to ground stations and to aircraft in flight. Improved weather briefing was an incidental benefit, as weather personnel learned to talk the language of the aircrews and acquired a firsthand understanding of their needs. In spite of such advantages, route weather missions flown one or two hours ahead of scheduled flights proved disappointing; they were too early to benefit other aircraft by air-to-air radio and too late to provide detailed information to forecasters.31 By contrast, area reconnaissance, when begun in 1944, proved so successful that weather became thereafter a negligible cause of aircraft losses. Weather stations at Waller (Trinidad), Belém, and Morrison fields each had two aircraft used for area reconnaissance, and a seventh was kept in reserve at Miami, Florida.32

As air traffic across the Atlantic increased, differences between American and British methods of processing weather information led to confusion and then to demands for separate services. Consequently and on recommendation of a joint RAF-AAF board, North Atlantic terminals offered both American and British weather services. After July 1943 American aircraft flying the North Atlantic were under the watchful eyes of AAF weather and operations personnel. Forecasting was done chiefly at mainline stations through which traffic passed en route to and from Prestwick, Scotland. Transatlantic briefing

* See below, pp. 332-33

Page 324

of flight crews was done first at Gander Field and later at the American base at Harmon Field, also in Newfoundland.33

AAF units in the British Isles were almost completely dependent on British weather services during their first months of operation in the United Kingdom. Extensive use of British weather maps and instruments procured through reverse lend-lease saved both time and shipping space, but at the cost of some confusion in supply procedures. Synoptic reports from AAF stations were transmitted over British nets, since it was mid-1944 before American teletype equipment was generally available. The 18th Weather Squadron was sent to England in August 1942 as token of a plan to make the Eighth Air Force ultimately independent of its British ally.34

Weather operations in Africa began in support of the transport and ferrying route across Central Africa that had been pioneered by the British and that was further developed by Pan American Airways for the movement of aircraft and supplies from the United States to the Middle East.* By June 1942 some nine weather officers and sixty enlisted weathermen were on duty at various points extending from Accra on the Gold Coast to Egypt. A newly activated 19th Weather Squadron established its headquarters at Accra during the summer with responsibilities reaching all the way into the Middle East, where the Ninth Air Force was beginning to operate, and southward to cover an emergency air route being developed below the Equator against the possibility of an Axis victory in the north.35 By the end of the year the responsibilities of the 19th Squadron reached from Accra to the border of India.

The 10th Weather Squadron, with headquarters at Delhi in India, faced one of the more difficult assignments in the AAF – to assist in the support of China by way of the famed “Hump” air route. Shorthanded, as were most AAF organizations in CBI during the earlier part of the war, the 10th Weather Squadron found the reports supplied by the meteorological department of the Indian government ill suited to its needs. Worse still was the situation across the Hump at Kunming, where a single officer and six enlisted men depended primarily upon data collected through a Chinese air warning system that was far more expert at spotting Japanese planes than in observing developments pertinent to weather forecasting.36

Between Kunming and Dinjan in India, AAF planes shuttled along

* See above, p. 46.

Page 325

a route already famous for its stormy weather. The route passed through the turbulent meeting place of three major Eurasian air masses. Low-pressure masses from the west moved along the main ranges of the Himalayas to the Hump, where highs from the Sea of Bengal clashed with Siberian lows. As late as January 1945, when earlier shortages of men, material, and experience had been very largely overcome, a single storm over the Hump cost ATC nine aircraft and 31 persons killed or missing.37 This, to be sure, was one for the record, but throughout the war unfavorable weather remained the greatest single cause of fluctuations in the flow of air traffic between India and China.

Not a little bickering marked the relations between the 10th Weather Region and the India-China Wing of ATC, which was hard pressed to meet fantastic goals for tonnages delivered across the Hump. Dissatisfaction with the situation in India and China probably contributed to ATC’s bid in the latter half of 1943 for control of weather services along air routes on which ATC was the principal user.* Bickering continued,38 but the record of the Weather Service in CBI was not wholly one of frustration. When the B-29’s of XX Bomber Command began operations from Indian bases against Japan and Southeast Asia in 1944, the new responsibilities were met successfully. Chinese reverses at the hands of Japanese ground forces soon drastically reduced the coverage provided by China’s air warning net, but a newly established weather central at Chengtu offset this disadvantage. The progress of U.S. naval forces in the Pacific made possible the provision of up-to-date reports from submarines and other vessels on duty along the Chinese and Japanese coasts. In return, Chengtu was able to provide weather reports of use to fleet units operating in the Pacific.39

Asiatic weather still held many mysteries, and the Superforts depended finally on weather planes, fully armed B-29’s which flew ahead on the route of attack to send back a last-minute report.† But the Russians were now more cooperative in supplying information regarding weather in Siberia, and, with the aid of observations by American personnel on the Asiatic mainland, the Allies were beginning

* Actually, however, the experiment with a transfer of weather units to ATC came in the Caribbean and the South Atlantic. Strongly protested by weather officers looking towards an integrated and unified weather system, the experiment was abandoned at the end of the year.

† See below, pp. 333-34.

Page 326

to turn the tables on the Japanese. It was often possible to predict today tomorrow’s weather in Japan or in the Philippines.40 For assistance in strikes against Southeast Asia some help came from OSS agents operating behind enemy lines.41

Meanwhile, back along the air route from the United States the responsibilities of the Weather Service had been greatly extended as a result of Allied campaigns in North Africa and the Mediterranean. The transfer of the weather service from the Signal Corps to the Air Corps in 1937 had made the latter organization the Army’s primary agent in all matters relating to weather intelligence. In other words, the Air Corps was obligated to provide such services as other arms might require of it. Actually, little thought was given to the problem until late summer 1942, when the impending invasion of North Africa naturally tended to raise the question. Alert to the possibility that the ground and service forces might develop independent services of their own in the absence of forehanded action by the AAF, General Arnold urged that the Director of Weather give immediate attention to the problem.42 There soon came from the War Department General Staff a proposal for a unified national weather service to be established at the Joint Chiefs’ level – one that would combine the services of the Army, Navy, and Weather Bureau in one organization fully equipped to meet all needs, including studies pertinent to general military planning. The discussion continued into the winter but ended with a decision which left existing arrangements basically unchanged.* Thereafter, as before, the AAF Weather Service developed an organization existing primarily for the support of air operations, but now it had a new sense of its obligations to sister services.43 In the United States the AAF Weather Service intensified its efforts to advertise among ground and service organizations the assistance it was equipped to give. It also gave new thought to the services it might render.

The general pattern that would be followed in combat theaters was foretold by developments in North Africa. The 12th Weather Squadron, some of its components shipped out from the United States and others purloined from personnel in the United Kingdom, was assigned to the Twelfth Air Force. Thus the squadron commander, who also

* The subject was more than once revived thereafter, as in a proposal of 1943 to use surplus meteorological officers in the AAF for the staffing of a separate organization for the ground and services forces. See above, p. 315.

Page 327

served as regional control officer, became weather officer for the ranking air commander in the theater, through whom the theater commander could easily secure such assistance as he might require for his operations. The demands at first were not too heavy. They increased as plans were drafted for amphibious assaults on Sicily and Italy in 1943, but the work of the Weather Service continued to be overwhelmingly concerned with air operations. As personnel became available, weather officers were assigned at each echelon down to the combat group level. After the Axis forces had been cleared out of North Africa, responsibility for weather service to an increasing air transport activity through the region fell also on the 12th Squadron. Eventually, in August 1944, the 12th moved its headquarters forward to Caserta in Italy, and a newly created 13th Squadron took over at Algiers with responsibility for Northwest Africa. In time, it too moved forward, leaving to the 19th Squadron, with headquarters now at Cairo, full responsibility for Africa and the Middle East.44

Experience soon had demonstrated that the concept of fixed weather stations, borrowed from the practice within the United States, was ill suited to the fluid conditions of a combat theater such as Northwest Africa. After weather stations operating close to the fighting front had come close to being overrun by momentarily successful enemy forces during the first winter, the need for mobility was impressed upon authorities both in the theater and at home. Later extremely mobile unit equipment was provided for squadrons supporting tactical operations.45 The establishment of the Fifteenth Air Force late in 1943, for collaboration with the Eighth Air Force in fulfilling the objectives of the Combined Bomber Offensive, brought new responsibilities and a need for closer liaison with weather services in the British Isles. The normal assistance of the weather squadron was supplemented after November 1943 by the establishment of a special weather reconnaissance detachment of six P-38 pilots and twenty-two enlisted men who operated under the immediate direction of the weather officer of the Fifteenth Air Force. Its duty was to send weather planes ahead of the bombers for a final check on weather over the target which might result either in cancellation of a planned mission or diversion to alternate targets.46 However great the progress of weather forecasting, the science was not yet perfected.

The experience gained in North Africa and the Mediterranean was

Page 328

turned to good advantage in preparations for the climactic invasion of western Europe. Meantime, the 18th Weather Squadron in Britain had developed an organization adapted to the peculiar requirements of the strategic bombing operations of the Eighth Air Force. Squadron headquarters were located at air force headquarters. Subordinate headquarters were established for each of the three combat divisions, for each combat wing, and for each combat group: Forecasts sent down from the weather central at headquarters were interpreted with reference to local problems of take-off and assembly, but otherwise they remained unchanged.47 The 18th Squadron also served the needs of ATC at British terminals. In a variety of ways the British continued to assist.

A second weather squadron, the 21st was sent to England during the summer of 1943 for assignment to VIII Air Support Command, forerunner of the Ninth Air Force soon to be established for direct support of the coming invasion of Europe. It was a fully mobile outfit, equipped and trained for movement with the army across the Channel and into Germany. Its commander became the weather officer for the Ninth Air Force on its activation in October.48 After the establishment in January 1944 of USSTAF, a joint headquarters through which General Spaatz exercised operational control of the strategic bombing of the Eighth and Fifteenth Air Forces and administrative control over the Eighth and Ninth Air Forces, the office of Director of Weather Services was created in February at that headquarters. In the following March General Eisenhower assigned to USSTAF the responsibility for providing and co-ordinating weather services for all U.S. forces in the European Theater of Operations. In the preparation of forecasts that would control the timing of the assault in Normandy, the new office shared responsibility with the weather centrals of the British Admiralty and of the RAF.49

After the invasion had been mounted, several adjustments of organization gave needed flexibility to a service in which one part, still basically the old 18th Squadron, remained in Britain to serve from its fixed stations the heavy bombers of the Eighth Air Force while the other moved onto the Continent in close support of the tactical forces of the Ninth Air Force. There were now no serious shortages. The experience of three years of war had taught its lessons. Performance was good.

Page 329

Operations – Pacific

When the Japanese attacked Pearl Harbor, the recently activated 7th Weather Squadron in Hawaii had four weather stations in operation – located at Hickam and Wheeler Fields on Oahu, at Homestead Field on Molokai, and at the newly developed air base on Christmas Island.50 In the effort to extend the South Pacific air route southwestward to Australia and then to the Philippines, which currently was the highest priority project affecting Pacific air operations, help could be expected from the national weather services of New Zealand and Australia. What could be expected, it soon became all too apparent, of the 5th Weather Squadron in the Philippines was highly problematical.

By summer 1942 detachments of the 7th Squadron had been located at key points along the route leading down from Hawaii to the Southwest Pacific, A joint weather central had been established at Noumea in New Caledonia through co-operation of New Zealand, the U.S. Navy, and the AAF.51 In Australia, to which General MacArthur had transferred his headquarters after the fall of the Philippines, arrangements were being made for an Allied Air Force Meteorological Service. For the moment the heaviest responsibilities fell upon the Australian Meteorological Service and the RAAF Meteorological Service. A handful of AAF weather personnel had found their way to the new theater, and a 15th Weather Squadron had been activated for assignment to the Southwest Pacific in the preceding April, but this unit did not reach its station until mid-August. Assigned to the Fifth Air Force with headquarters at Brisbane, its commander became regional control officer and staff weather officer for Maj. Gen. George C. Kenney, MacArthur’s newly arrived air commander. Its activities were closely co-ordinated with those of the RAAF weather service to avoid unnecessary duplication, but in practice and by agreement the 15th Squadron concentrated its efforts on meeting the peculiar needs of the Fifth Air Force, U.S. component of the Allied Air Forces.52

For the South Pacific, where the First Division of the U.S. Marine Corps had begun the arduous campaign for the Solomons in August, a 17th Weather Squadron was activated in September 1942. Personnel of the 7th Squadron already on duty along the South Pacific air route were transferred to the new squadron, but not until December was

Page 330

the 17th fully in place with headquarters at Noumea. The squadron was assigned to Maj. Gen. Millard Harmon, an airman commanding U.S. Army Forces in the South Pacific.53 As in Australia, there was close collaboration among the Allies and between the American services in the accumulation of weather data – through reports from ships at sea, aircraft in flight, coast watchers behind enemy lines, and trained observers posted at strategic spots. To this joint effort the 17th Squadron contributed its share, but its primary obligation was to function as a source of weather intelligence for the flyers of the newly created Thirteenth Air Force and for ATC and tactical planes on their way through the area.

It was difficult to get enough equipment, and manpower shortages continued for a time to be embarrassing. Nearly all newly arrived weather personnel required from a few days to six weeks of additional training in subject matter that ranged from the basic principles of weather to studies in tropical weather analysis, route forecasts, and the briefing of air crews.54

Across the Pacific in Alaska the attack on Pearl Harbor brought new concern for approaches to the North American continent that lay uncomfortably close to Japan itself. The Air Corps had maintained a weather detachment at Ladd Field, Fairbanks, since 1940 and had added installations at Anchorage, Yakutat, and on Annette Island. Within three months after the beginning of war, new stations were established at Nome, Northway, Naknek, Fort Randall, and on Umnak Island, farthest west of all stations before the Japanese attack on Dutch Harbor in June 1942. With Japanese forces occupying Attu and Kiska out along the Aleutian chain, U.S. forces occupied Adak late in the summer and opened there a weather station in October. Early in 1943 the line had been pushed out to Amchitka, whence it was extended by the end of the summer to Attu and Kiska, from which the Japanese withdrew in advance of landings by U.S. assault forces in August 1943.55

Weather in the Alaskan area had a threefold importance for the war effort, First, it affected, and often disastrously, air and other operations in that area. Despite the heroic efforts of weather personnel and close co-operation among representatives of the AAF, the Navy, the CAA, and the US. Weather Bureau, no great success was achieved in overcoming the natural disadvantages of the area for combat air operations. Indeed, as has been recorded elsewhere in this history, it

Page 331

was the weather which perhaps in the last analysis ultimately “relegated the Alaska-Aleutians area to the place of a relatively inactive theater.”* But it was not alone for the sake of local operations that the weather services of the 11th Region were performed. The fuller information made available for this area was pertinent to a better understanding of weather conditions over much of the North American continent and of the Pacific. And no less important was the assistance rendered in keeping open a vital air supply line to our Russian allies.† In this last task, the 11th Squadron shared responsibility with the 16th Weather Squadron established in August 1942 for a region that embraced the Pacific Northwest, both of the US. and of Canada.56 The men who thus helped to keep this line open endured hardships very similar to those experienced by weather personnel serving in the North Atlantic.‡

Until the launching in 1943 of the Navy-directed offensive in the central Pacific and of MacArthur’s victorious drive along the New Guinea coast, arrangements for AAF weather services in the Pacific followed more or less conventional patterns. Weather stations tended to be of the “fixed” variety, and, despite close co-operation with other services in the operation of joint weather centrals, AAF units attended to the needs primarily of their own forces. When the battle-line began to move northward, new requirements for mobility appeared. Fifth Air Force sought and secured enlargement of manning and equipment tables to provide for additional detachments needed in the forward movement of MacArthur’s island-hopping campaign. The 7th Region sent forward into the Gilberts and the Carolines mobile (“packaged”) weather units equipped to follow the assault forces ashore and to provide almost immediate service at any captured airfield. Enlarged geographical areas of responsibility, together with the need for adjustment to changing command arrangements, gave utility to the organization of provisional group headquarters for administrative control of weather units. Thus, in the summer of 1944, Army Air Force, Pacific Ocean Areas (AAFPOA), the superior headquarters established for all Army units operating in the central Pacific, created a provisional group with jurisdiction over the 7th and 17th

* See Vol. IV, p. 363.

† See above, pp. 165-70.

‡ The men put on station at St. Mathews Island in the Bering Sea in September 1943 for observation of ice conditions and air masses from Siberia saw no one from the outside until May 1944.

Page 332

Weather Squadrons. The Thirteenth Air Force having now moved forward from the Solomons into the Southwest Pacific and having been teamed with the Fifth Air Force under the Far East Air Forces (FEAF), Kenney also resorted to a provisional group for administrative control of the 15th Squadron and a newly assigned 20th Weather Squadron.57

In the Pacific, as in Europe, combat commanders found it necessary to supplement normal weather services with special reconnaissance flights to determine more exactly weather conditions over specific target areas. This need had not been wholly unanticipated, especially for an area in which the enemy’s initial victories had closed off to normal reporting a vast and important segment of the globe. As early as November 1941 it had been proposed at AAF Headquarters that several weather reconnaissance squadrons be organized with special equipment and manning tables to include trained weather observers. Finally, in August 1942 a test squadron was established at Patterson Field, Ohio, but the experiment failed to develop into a coherent program.58 Instead, requests from theater commanders for assignment of weather squadrons were met with the suggestion that they establish for themselves such services as were needed on the assurance that AAF Headquarters would assist in getting the planes desired. The Fifteenth Air Force used P-38’s. The Eighth at one time equipped a unit with Mosquitoes for service primarily as “pathfinders” through the uncertain weather of western Europe. Elsewhere any plane that was available and had the necessary range might be pressed into service, and often weather reconnaissance might become an additional duty for regular reconnaissance services. Thus weather reconnaissance usually served the immediate and specific ends of determining the weather over target, or the route that was open to target, rather than the more general purpose, as originally planned, of increasing the information available for study and forecast of weather in a large geographical area.

Only in two instances did services comparable to those originally considered develop. In 1943 the test squadron at Patterson Field was equipped with B-25’s and was later redesignated the 1st Weather Reconnaissance Squadron Air Route (Medium), for service with ATC along the North and South Atlantic air routes. In time, experience demonstrated, as previously noted,* that area reconnaissance paid

* See above, p. 323.

Page 333

the higher dividends. The 3rd Weather Reconnaissance Squadron (Heavy) began operations for ATC early in 1945, with one flight taking over the heavy bombers already assigned to weather missions in the North Atlantic and another flying off the northwest coast of the United States.59

In the end, the AAF added two more weather reconnaissance squadrons, both of them assigned to theaters in which the B-29 was deployed. The 2nd WRS, activated early in 1944, was sent to CBI, where its planes served XX Bomber Command and the Fourteenth Air Force in China and Eastern Air Command in Burma. The fourth weather recco squadron, the 655th Bombardment Squadron (H), went to the aid of XXI Bomber Command, whose B-29’s on Saipan and Guam in late 1944 took over from XX Bomber Command the task of bombarding the Japanese homeland. Activated in August 1944 and fully in place by the following spring with an advanced echelon on Iwo Jima, the unit was redesignated the 55th Reconnaissance Squadron (VLR), Weather, in June 1945.60

The 7th and 17th Weather Squadrons had been consolidated in the preceding November, a move which left the augmented 7th Squadron with full responsibility throughout POA. This squadron, in turn, had been deactivated in February 1945, its personnel and equipment being assigned to the newly formed AAF Weather Services, POA. Its responsibilities covered a wide range of activities: a continuing service for transient planes along old and newly developed air routes, assistance for tactical planes operating against bypassed enemy garrisons in the Solomons and the Gilberts or flying against such newer targets as Truk and Iwo Jima, and participation in the operation of the joint weather central on Guam.61 But the heaviest obligation was to the B-29’s, whose strikes against Japanese targets carried them into one of the more turbulent weather regions of the world. Some assistance in predicting the weather over the northwest Pacific came now from China* and from Russia, although Russian reports were usually so delayed as to be of limited value.62 Help came also from the increasing number of U.S. Navy vessels operating close in to the Chinese and Japanese shores. Like air forces in other theaters, however, XXI Bomber Command had to rely finally on air reconnaissance. P-51’s, P-61’s, B-24’s – all these were used, but only the B-29 and its adaptation for reconnaissance purposes, the F-13, had the full reach required.

* See above, p. 325.

Page 334

As the planes became available, they were used both for regular scheduled weather recco flights and as weather planes flying in advance of the striking forces.

At war’s end the organization of weather services in the Pacific was undergoing still another shift. This time plans called for a single service for the entire Pacific area and its assignment to the Pacific command that would direct the climactic invasion of Japan. Fortunately, that invasion became unnecessary, and the assignment was made instead to the newly independent AAF Weather Services.

Technical and Other Problems

The AAF Weather Service contributed significantly to an extraordinary growth of meteorological science during the war years. It is often difficult, however, to separate the AAF’s contribution to this growth from that made by other agencies, especially those belonging to the U.S. Weather Bureau and to the U.S. Navy. Collaboration among these three services was particularly close in the area of experimental research. Close relations were also maintained by each of them, often on a joint basis, with university research centers, from whose staffs many of the key men in the government services had been temporarily borrowed. An exchange of experience came naturally among the relatively small number of leaders who were expert in the field, and the pressure of wartime demands added its own encouragement to this practice.

In general, the AAF Weather Service may be described as primarily a “user” – that is to say, its energies were very largely absorbed in the organization, training, and equipping of weather units to meet the peculiar needs of its own combat and transport forces. For necessary development and improvement of meteorological equipment, it looked throughout the war years to the Signal Corps, with which a close liaison was maintained in the office of the Chief Signal Officer at Fort Monmouth, New Jersey. To this office the AAF specified its requirements. Research thus initiated was centered, with rare exceptions, in the Meteorological Branch, Eatontown Signal Laboratory, of the Signal Corps. Service and field tests were supervised by the AAF Board at the Eglin Field Proving Ground and at the AAF Tactical Center at Orlando, Florida, where all testing was eventually centered with the heaviest responsibility assigned to the 26th Weather Squadron. Acceptance of an item by the AAF still left to the Signal Corps full

Page 335

responsibility for its procurement or production in the quantity desired. Throughout the war approximately 90 per cent of the meteorological projects undertaken by the Signal Corps were initiated at the request of the AAF.63 Under this arrangement, the AAF’s contribution to technological achievement depended very largely on the sharpness with which it defined its problems and the effectiveness with which it passed on to the laboratory the field experience of the user.

This is a role that in the modern age of technology is by no means, to be despised, and in return for what it borrowed in the way of aid from other services the AAF had much to offer. Here and there it initiated research programs of its own, some of them involving no doubt a certain duplication of the efforts made by other services, but some of them also contributing to the solution of problems common to all the services. More important, the AAF’s far-flung weather stations extended systematic reporting into many regions hitherto uncovered or but imperfectly covered, with results of great benefit to all who were concerned with the problems of forecasting. Its weather reconnaissance missions supplemented available data with reports from regions in which no fixed station could be established. As the operator of the world’s most extensive and elaborate system of airways, and with a dozen combat air forces in daily need of accurate weather data, the AAF’s records provided a valuable check on the several techniques tested for forecasting. Especially helpful were the data made available on long-range forecasts. AAF pilots, as did Navy pilots, pioneered in the use of special radar equipment for the penetration and observation of storms which had always been a principal hazard to flying. AAF planes patrolling the Caribbean gave timely hurricane warnings for civilian as well as military agencies and tracked the hurricanes so closely that ATC soon turned the disturbances to advantage by plotting courses for its transports that offered the help of tail winds resulting from the storms.64

The risk from storms presented an especially important problem in many areas through which the AAF was forced to fly long missions both of transport and of combat. In addition to the help that came from an increasing reliance upon regular area reconnaissance flights, assistance was had from self-contained automatic stations put down in remote regions. Radar, sensitive to electrical discharges and other convective disturbances within a storm, made it possible late in the war to locate and plot the course of storms many miles away from the

Page 336

points of observation. A three-station network, with stations in New Jersey, Bermuda, and Florida, was in operation by June 1944. In May 1945 a “sferics” network was also established for round-the-clock operations in the central Pacific.65 Still another adaptation of radar that proved especially helpful to air operations was the rawinsonde which made possible the measurement of wind velocity and direction at high altitudes without the necessity for optical tracking heretofore required.66

An administrative and operational problem that frequently intruded its questions into the development of the AAF Weather Service was one of communications. The value of weather reports depended so heavily upon their freshness, and upon the completeness of their coverage, that any weather service necessarily depended for its effectiveness upon an elaborate communications network. The channels of communication for the collection and dissemination of weather intelligence were varied and included those under civilian as well as military control, but the Weather Service’s dependence on the Army Airways Communication System was especially heavy. AAF policy forbade the development of a competing system and assigned to AACS full responsibility for the transmission of weather communications. The division of responsibilities, however, could not be quite so neat as this policy dictated. Special requirements, as in the extension of facilities into regions where there was no other demand for service or in experiments with facsimile transmission of weather reports, encouraged development of independent communications facilities. Here and there, among other places in India, strong sentiment in favor of having the Weather Service operate its own communications system developed. But this sentiment was overruled at headquarters, in Asheville as well as in Washington. A Communications Facilities Section of the Weather Service was kept busy in the continuing effort to see that communications needs were met and to maintain the necessary liaison with other agencies.67

The problem of communications became the more difficult because of the need for adequate security in the transmission of weather reports. The public release of weather information by commercial radio stations and in the press was promptly discontinued after the pearl Harbor attack, but it took time to work out the details of an effective security policy AAF Regulation 105–1, issued 6 March 1942, directed that all data pertaining to weather less than seven days

Page 337

old be classified as confidential and that dissemination of information on the weather be limited to members of the armed forces or their representatives. No weather reports or forecasts were to be broadcast or transmitted after 19 March, except in emergencies endangering life or property. Control towers, AACS radio stations, and aircraft in flight were to transmit weather data only in code.68

After fears of enemy attack on US. cities had subsided,* policy was further clarified in AAF Regulation 105–1, issued 18 September 1943. Domestic weather information was classified as restricted or above, according to its character, and that originating outside the United States was classified in accordance with current directives of the War and Navy Departments. Displays of information in weather stations were to be adequate for operational needs but accessible only to authorized personnel. Control towers and AACS radio stations were to transmit only in prescribed forms, using appropriate scrambles. Aircraft in flight were to disclose weather information by radio only on specific orders of competent authority and when using a cipher approved by the War Department. These restrictions could be relaxed in cases of emergency, but only to the extent necessary to protect life and the aircraft involved. The Weather Bureau and the CAA would provide weather information to military pilots on nonmilitary airdromes upon presentation of proper identification.69 In the following November the Office of Censorship authorized the release within the United States of local weather information on the condition that there be no mention of ceiling, visibility, wind direction, or barometric pressure.

The inherently difficult problem of weather security was further complicated by its international character, particularly along North Atlantic routes and in adjacent parts of the United States and Canada. Because the United Kingdom was within range of German bombers, the British were determined that the enemy should not get from them the slightest hint as to weather moving eastward across the Atlantic. They insisted that the need for weather data should take precedence over security only in real emergencies. AAF spokesmen took a directly opposite stand. They contended that it was better to take such risks than to deprive friendly forces of needed intelligence on weather conditions. Both the Army and the Weather Bureau maintained that the need for weather security decreased as Allied forces gained air and

* See Vol. VI, pp. 112-16.

Page 338

ground superiority. But only after 6 May 1945 were weather reports from all of northwestern Europe, except the coastal areas, broadcast in the clear.70

Elsewhere, too, authorities showed little hurry to lift wartime weather security restrictions. Weather security in the Caribbean area, in Mexico, and in South America was relaxed in the fall of 1943, but the Canadian government, in conformity with British policy, continued to enforce rigid restrictions east of the 80th meridian. In Alaska, U.S. authorities did not relax regulations until November 1944, and then only partially. The Aleutians remained subject to tight controls, as did, of course, the whole Pacific area until the final surrender of the Japanese in August 1945.71