An Alberta study to objectively measure hailfall intensity

During the summer of 1973, two networks of hail detectors were established in a hail‐prone region of southern Alberta, in conjunction with the hail suppression investigations being carried out by Alberta Hail Studies (ALHAS).² Two hundred and seventy‐two farmer volunteers maintained the detectors in two regions totalling 1600 mi², providing a mean station spacing of 2.5 mi. Five dense networks with a detector spacing of 0.25 mi were also operated during August.

These detectors successfully recorded the hailfall on 17 severe thunderstorm days. The areal coverage of the hailfall was found to be less sporadic than was popularly believed, and the data revealed two different spatial scales of hailfall variation. A preliminary examination of the significance of these results for the design of precipitation (and particularly hail) measuring networks is undertaken.