Invited Speaker: Hail damage reduction activities

Operational hail damage reduction (commonly called “hail suppression”) programs continue in many countries, including Argentina, Canada, China, France and parts of Eastern Europe as well as the United States. By way of contrast, research activity related to the subject has greatly diminished: A search for “hail suppression” turned up just fifty papers published over the past decade in journals of the American Meteorological Society, with a similar number appearing in Atmospheric Research. Many of those papers do not deal in any substantive way with hail damage reduction topics; none discuss any systematic evaluation of the effectiveness of the on-going programs. (One did look at the effects of the seeding upon the associated precipitation in the target area.)

This paper will present an overview of some of the existing operational programs and discuss current understanding of the effectiveness of seeding in reducing hail damage (along with problems in evaluating such effectiveness). Gaps in our understanding of the hail development process and how it might be influenced by seeding will be highlighted. Some research avenues that could provide a basis for improved effectiveness, especially if modern technologies such as polarimetric radars and improved numerical cloud models could be brought to bear, will be discussed.