A Case Study of Cloud Seeding to Reduce Hail Damage
Keywords:hail, cloud seeding, Kansas, STEPS, WKWMP
A large tornadic hail-producing supercellar thunderstorm developed in northwest Kansas on the afternoon of 29 June, 2000. This storm was observed by a network of meteorological research polarimetric radars. It was seeded by the Western Kansas Weather Modification Program for more than 2 hours as it transitioned from a multicellular to a supercellular mode, produced an F2 tornado, and produced copious hail ranging in diameter up to 4.5 cm for over 1½ hours. Published studies based on the research radar observations provide a time history of this storm’s hail production in terms of volumes of the storm containing hail, graupel, and other precipitation types, as well as volume containing significant updraft. Using these analyses, it is shown that the storm invigorated, and the volume of the storm containing hail increased dramatically shortly after seeding began. Of course, it is not known how the storm would have developed and how much and how big would have been the hail had it not been seeded. It is suggested that a large sample of similar storms, both seeded and unseeded, be analyzed by these or similar polarimetric radar-based techniques in order to better understand the impact of seeding on hail development in thunderstorms. Such analysis could be done inexpensively using National Weather Service radar data.