Further results of Grossversuch. IV: The effect of the first rocket launched into a potential hail cell

Abstract The data obtained in Grossversuch IV about hail prevention triggered the hypothesis that only the first rocket launched into a potential hail cell decreases hail kinetic energy in an effect-time interval around 10 min after launching time. Several variations of a randomization test were applied to substantiate this hypothesis. All showed a tendency to confirm the hypothesis, the most significant result being a p value of 0.2%. However, since the test was applied to the data that had been explored to generate the hypothesis, the significant result should be interpreted as a strong hint rather than as a statistical proof.