A Logistic Regression Model Applied to Evaluate the Influence of Operating Time of AgI Ground Acetonic Generators on the Size and Hardness of Hail

In this paper we study the effect of operating time of AgI ground acetonic generatorsbefore hailing on the hail characteristics (size and hardness), and hailfall crop damages.The study was carried out in a large area of northern Spain over an area of 12,000 km<Superscript>2</Superscript>.Data are available from 1,984 hailstorms that occurred from May to September in theperiod 1982–1987. By using several Stepwise Logistic Regression Models, a statisticalsignificant (p > 0.05) decrease shows up in hailfall crop damage due to hail prevention.This effect is due to the influence of ground seeding on the hardness and mainly on thesize of hailstones. Copyright Kluwer Academic Publishers 2004