Hailstone size distributions in southwestern France

摘要: Abstract A hailpad network, intended to draw up a large-scale, long-term physical climatology of hailfalls, is being installed in southwestern France, one the severely hailed regions world. The first five years operation this network have enabled organization suitable standardization data. classical exponential form well adapted represent mean size distribution hailstones sampled at several locations, but we suggest replacement usual concentration parameter form—the number zero diameter hailstones—by smallest really counted on pads, so as not amplify, with regression, relationship between and slope parameter. There significant correlation altitude 0°C isotherm level, regression enables determination level. By contrast, level weak. When these results are compared Ludlam's model hailstone melting, they that hail mainly falls within downdrafts. With limited amount data presently available, no appears parameters storm thermodynamics, larger while smaller frontal storms than intramass ones, result explaining why most severe hailstorms France frontal.