Characteristics of hail in the U.S. from a high density volunteer observing network

The Community Collaborative Rain, Hail and Snow network (CoCoRaHS) provides a mechanism for volunteers from across the U.S. to quantitatively measure and report hail. This study presents preliminary findings from CoCoRaHS hail measurement efforts. Examples of stone size distributions, stone hardness, stone concentrations (number of stones per unit area) and storm duration will be shown. For areas of Colorado where CoCoRaHS hail measurements have been taken for over 10 years using low cost hail pads, variations in spatial frequencies in hail of various severity will also be presented. One important discovery from this project is the tendency of CoCoRaHS volunteers to diligently report daily precipitation amounts but only intermittently report hail. Strategies for motivating better hail reporting will be discussed.