https://en.wikipedia.org/wiki/Hail_cannon https://en.wikipedia.org/wiki/Hail_cannon "There is no evidence in favor of the effectiveness of these devices. A 200

https://en.wikipedia.org/wiki/Hail_cannon https://en.wikipedia.org/wiki/Hail_cannon "There is no evidence in favor of the effectiveness of these devices. A 2006 review by Jon Wieringa and Iwan Holleman in the journal Meteorologische Zeitschrift summarized a variety of negative and inconclusive scientific measurements, concluding "the use of cannons or explosive rockets is a waste of money and effort"."