Estimating the Hazard of Ice Accretion in Canada from Climatological Data

Abstract

Ice storms are a major hazard which must be considered in structural design in all parts of Canada. The frequencies of occurrence of freezing precipitation are used to obtain a simple index of this hazard. To obtain more quantitative estimates, the total amounts of freezing precipitation in each storm are considered. Since recording gages rarely operate during these storms, the amounts are estimated from hourly weather reports and 6-hr precipitation measurements. The statistical distributions of the estimated annual extremes of ice-storm accretion and of contingent strong winds are examined, but the results are somewhat speculative because of the short duration of the period of analysis and the lack of confirming observations.