The entry says that Project Stormfury seeded four hurricanes in twenty-one years and spent most of the rest of the time waiting. This piece is about the waiting: the rules that made a storm eligible, the arithmetic of how many storms those rules allowed, and what the project tried to do about it.

The rules

The first rule was a box on the map. Until 1966, by the Navy’s account, the project was “limited by restriction to a prescribed area, a band in the southwestern North Atlantic between Bermuda and Puerto Rico.” A storm was eligible if it was in the band and would stay there. The forecaster’s memorandum before Beulah in August 1963 shows the rule at work: Gordon Dunn at Miami advised Simpson by Navy radio that the hurricane “at any likely rate of acceleration will still remain east or northeast of Bahamas by 0200E Sunday,” and so “would meet the safety specifications which had been established for the experimental operations.” The Washington Sunday Star explained it to its readers two weeks later: Beulah “could not possibly have hit the Atlantic Coast within 48 hours after the chemical attack,” a precaution that “was necessary because scientists cannot be sure what a hurricane will do when tampered with.”

For 1967, on the Advisory Panel’s recommendation, the box became a probability. “Any suitable storm in the southwestern North Atlantic was eligible for seeding as long as there was a small probability (10% or less) of its center approaching within 50 miles of a populated area within 24 hours. This change in criteria was made possible by the increased accuracy of hurricane forecasts.” The Gulf of Mexico and the Caribbean were added. The 1969 annual report gave the two reasons for keeping storms away from land, and they are worth setting side by side, because one is about safety and the other is about the experiment. “First, a storm seeded further at sea will have reverted to ‘nature’s own’ before affecting a land mass. Second, marked changes in the structure of a hurricane occur when it passes over land. These land-induced modifications would obscure the short-range effects produced by the seeding experiments and greatly complicate the scientific evaluation of the results.” A storm also had to be within reach of the seeders, and strong enough to be worth seeding: by the rules as the Senate’s researchers summarised them in 1978, “predicted to be within 700 nautical miles (1,100 kilometers) of the operating base—Miami or San Juan—for at least 12 hours,” with maximum winds of at least 65 knots.

The count

William Mallinger of the National Hurricane Research Laboratory did the arithmetic, and published it in the annual reports of 1967, 1968, 1969 and 1970. He took the tracks and the forecasts of every hurricane since 1954, the first year for which the Weather Bureau’s forecasts were recorded by latitude and longitude, and asked which of them would have been eligible under the rule and under various relaxations of it.

The 1969 study tried lengthening the season and shortening the clock. Of the hurricanes of 1954 to 1969, only three, 8 per cent, would have been eligible in June, July or November, “This suggests that benefits of extending the STORMFURY season to the other months may be less than the probable costs and inconvenience of having all of the forces of other programs committed to STORMFURY for a longer period.” Cutting the 24 hours to 18 would have added eight hurricanes in sixteen years, three in the Atlantic, three in the Caribbean and two in the Gulf; cutting it to 12 would have added three more, all in the Gulf. Raising the 10 per cent to 25 or 50 “would not be significant,” and besides, “retention of the ‘10% or less’ portion of the rule appears advantageous politically until we really understand the effects of the modification attempts.” The panel recommended the 18-hour rule and a season from 1 July to 1 November; the 18 hours was adopted in 1970. Under it, Mallinger reckoned in 1970, the Atlantic, the Gulf and the Caribbean together offered an average of about 2.35 eligible hurricanes a year. Over sixteen seasons the project had caught three.

The typhoons were the other column. Under the same guidelines, a storm within 600 miles of Guam or Okinawa with winds of at least 65 knots, the western North Pacific offered fifty-five eligible typhoons in the years studied, seven of them counted from both bases, or “5.3 per 3-month period,” more than twice the Atlantic’s rate. Mallinger’s 1970 update put the point plainly: the comparison “is particularly important because proper bases for operations in the Pacific are needed if there is to be a sufficient increase in experimental opportunities to justify the Project’s move to the Pacific.” The hurricanes of the eastern Pacific, off Mexico, he dismissed in a sentence as “not considered to be suitable experimental targets.”

The seasons

The record of the seasons is the record of the rule. In 1962 there was nothing suitable. In 1963, Beulah. “In 1964, the aircraft instrumentation was not ready.” In 1965 Betsy came too close to land and went on to strike Florida and Louisiana, and Elena never came within range. In 1966 the forces went on alert for Faith, which recurved before it entered the area, and flew Inez for data. In 1967, the Navy’s summary recorded, “for the first time in 14 years, or ever since official United States Weather Bureau forecasts were recorded by latitude and longitude for the areas and times concerned, no eligible hurricane appeared during the operational period 8 August to 15 October.” In 1968, none. In 1969, Debbie, and Inga, “technically eligible when near Bermuda, but … not seeded because she had poorly formed eyewall clouds, was weak, moved in an unusual manner, and in general was not desirable for experimentation.” In 1970 the forces went to Puerto Rico for Tropical Storm Dorothy, which weakened over Martinique and became a data-gathering mission on a tropical wave. In 1971, Ginger, seeded on 26 and 28 September though the design did not fit her. In 1972, “all of the hurricanes were too weak, or too close to land, or out of range.”

The Pacific

The Advisory Panel, meeting in Washington from 28 to 30 January 1971 with Debbie’s result eighteen months old and nothing to follow it, issued two recommendations ahead of the rest because they “need immediate action if necessary planning is to be accomplished.” The first: “The Panel recommends that appropriate agencies of the government intensify efforts to solve the financial, logistic, diplomatic, and other problems associated with proposed operations of Project STORMFURY in the typhoon region of the Western North Pacific Ocean during the summer of 1972.” The reasons: “The increased opportunities for STORMFURY experiments to be expected from the typically greater frequency of Pacific typhoons in a large, sparsely populated oceanic region fully justify the expense and effort required to move Project operations to that area. There is every reason to believe that experimental results obtained in Pacific typhoons will be completely valid for Atlantic hurricanes.” The second was that the project acquire its own seeding aircraft, with room for project scientists aboard, longer range and endurance, and the ability to seed below 30,000 feet, because “The Panel considers it undesirable for the Project to have to rely on seeder aircraft from external units.”

The summer of 1972 came and went in the Atlantic. The Navy, which had provided every seeding aircraft the project had ever used, ended its sponsorship in 1973 to pursue goals nearer to defence, and NOAA’s DC-6s and B-57 were retired in the same fiscal year. NOAA ordered two Lockheed WP-3D Orions, built to the pattern of the aircraft that had been proposed for the Navy’s abolished reconnaissance squadrons. The plan, by the mid-1970s, was for five aircraft, the two Orions, NOAA’s C-130, an Air Force WC-130 and a NASA Convair 990, to operate from Guam from 1976 and, as the project’s chroniclers put it, “establish an operational hurricane modification technology within a few years.”

The governments of the western Pacific had not been asked, and when they were they said no. The Senate’s 1978 review of weather modification put it in one entry of its chronology, “1976: Chinese disapproval resulted in abandoning plans for Stormfury in the western Pacific,” and in a paragraph of its chapter on NOAA: “Tentative plans were formulated to conduct seeding experiments on typhoons of the western Pacific in view of the greater frequency of suitable storms in that region. These plans were canceled, however, when protests were received from the Governments of Japan and mainland China, although the Philippines had been favorable to such experiments.” The National Advisory Committee on Oceans and Atmosphere, reporting to the President in June 1976, drew the lesson: “Objections on the part of some western Pacific nations prevented this move and it will instead be conducted in the eastern Pacific and western Atlantic. It is important to the ultimate success of this effort that we recognize that other nations which might be affected, or which believe they might be, have a legitimate interest in understanding its expected benefits, the risks involved, and the safeguards proposed.”

Two years earlier the project had learned what “believe they might be” meant. After Hurricane Fifi devastated Honduras in September 1974 there were charges that an American attempt to weaken the storm had caused the disaster, “a charge which the United States officially denied, since no hurricanes had been seeded under Project Stormfury since 1971.” The denial was true. It was also the kind of statement a project cannot afford to have to make.

Mexico

So the project turned to the hurricanes Mallinger had dismissed. Satellites had shown that the eastern North Pacific, off the west coast of Mexico, bred more hurricanes than anyone had thought, more in recent years than the western Atlantic. Bilateral consultations with Mexico began; in 1977 the State Department’s Interagency Study Group on weather modification, newly placed under the Bureau of Oceans and International Environmental and Scientific Affairs, had “dealt solely with the problems involved in the continuation of Project Stormfury,” negotiating with Mexico and “examining the potential problems of liability of the United States for damage done by official U.S. weather modification activities.” NOAA had SRI International prepare an environmental impact statement, published in February 1978, for what was now called the Hurricane Amelioration Research Project, to be run “collaboratively with the Mexican Secretariat of Agriculture and Hydrology,” with the goal of testing “the hypothesis that maximum surface winds in hurricanes can be reduced 10 to 15 percent or more by seeding the proper clouds in specified portions of the storms with freezing nuclei.” Operations would be based at La Paz, Mazatlán and Acapulco, within 600-nautical-mile sectors of each, from June to October, with the seeding done by day over eight hours. The statement considered the alternatives in a section of their own: not perform, postpone, perform in another area, use other modification methods.

In September 1977 NOAA announced a plan to seed one Atlantic hurricane that season, “as a rehearsal for full-scale resumption of multiple experiments during 1978, using the five newly instrumented aircraft.” The Senate’s researchers recorded what the full programme would need: “It is felt that 10 to 12 seeding experiments are required to verify the Stormfury hypothesis, taking at least two or three full hurricane seasons to realize sufficient seeding opportunities.” Ten to twelve, in a basin that had offered the project four in sixteen years.

No hurricane was seeded in 1977, or in 1978, or afterwards. “The international agreements required to move STORMFURY to the Western Pacific never materialized,” the chroniclers wrote in 1985. “Other attempts to move STORMFURY to the eastern Pacific or to Australia also met political resistance.” The Orions flew the Atlantic storms of those years, Anita, David, Frederic and Allen, as research flights, and what they measured is in the entry. The rules had kept the seeders away from every storm that might have hurt anyone, which was their purpose, and in doing so had kept the project to four storms in two decades, which was its undoing. The count was the control the project never had, turned the other way: a record of how seldom nature offered the experiment, kept carefully by the people who most wanted it to be offered.

Sources

• Max W. Edelstein, “Project STORMFURY Operations–1967,” in A Summary of the U.S. Navy Program and FY 1967 Progress in Weather Modification and Control, 26 October 1967. The band between Bermuda and Puerto Rico, the 1967 rule, and the season without a storm. archive.org
• National Hurricane Center, Hurricane Wallet Digital Archives, Hurricane Beulah 1963: G. E. Dunn’s memorandum of 22 August 1963. nhc.noaa.gov
• “Hurricane Team Waits Chance to Seed Storm,” The Sunday Star (Washington), 8 September 1963, page A-36. Library of Congress, Chronicling America
• Project Stormfury Annual Report 1969, Navy and ESSA, May 1970: the eligibility rule and its reasons, Inga, the Advisory Panel’s Recommendation Nine, and Appendix G, W. D. Mallinger, “Project STORMFURY Hurricane and Typhoon Seeding Eligibility.” archive.org
• Project STORMFURY Annual Report 1970, Navy and NOAA, May 1971: Dorothy, the Advisory Panel’s recommendations of February 1971, and Appendix L, W. D. Mallinger, “Project STORMFURY Experimental Eligibility in the Western North Pacific.” archive.org
• US Senate, Committee on Commerce, Science, and Transportation, Weather Modification: Programs, Problems, Policy, and Potential, 1978: the chronology, the chapter on NOAA’s programmes (the 700-mile rule, Japan and China, Mexico, the 1977 plan, the ten to twelve experiments), the NACOA report of 1976 and the Interagency Study Group, and the Fifi charge. archive.org
• NOAA, Environmental Impact Statement for the Hurricane Amelioration Research Project, February 1978. archive.org
• H. E. Willoughby, D. P. Jorgensen, R. A. Black and S. L. Rosenthal, “Project STORMFURY: A Scientific Chronicle 1962–1983,” Bulletin of the American Meteorological Society 66 (1985), pp. 505–514: the seasons of 1962 to 1972, the Navy’s withdrawal, the five-aircraft plan for Guam, and the agreements that never came. web.archive.org