In the May 1985 issue of the Bulletin of the American Meteorological Society, an article evaluating Project STORMFURY written by four Hurricane Research Division scientists was published. The Project was a twenty-year effort by the United States Government to test the hypothesis that seeding hurricanes with silver iodide would substantially alter the structure of the storms and reduce their maximum winds. However, during those two decades, only four hurricanes were actually seeded. This landmark paper examined all of the experiment results, the computer simulations, and the innovations in understanding tropical cyclone dynamics and concluded that the seemingly positive results of the experiments were questionable. The primary problems arose because 1) cloud microphysics measurements in hurricanes showed an abundance of ice particles and a dearth of supercooled water, so silver iodide wouldn’t substantially increase the rate at which supercooled water would freeze, and 2) frequent occurrence of natural eyewall replacements in the most intense hurricanes called the apparently positive results of seeding experiments into question.
This paper was published at a time when the high hopes of the 1950s and 1960s for the efficacy of weather control were waning and the public was becoming cynical about all Government efforts and scientific promises. Along with the inability of the Florida Area Cumulus Experiment project to demonstrate cloud seeding’s benefits, the entire field of weather modification shrank and U.S. Government funding dried up.
H. E. Willoughby, D. P. Jorgensen, R. A. Black, and S. L. Rosenthal, 1985: Project STORMFURY: A Scientific Chronicle 1962–1983. Bull. Amer. Meteor. Soc., 66, 505–514.