A bivariate analysis of temperature and rainfall series for snowfall return period estimation

The lack of snowfall observations makes snow return period estimation a relevant issue in areas characterized by the absence of snow gauges. Therefore, in these regions, the post-event effects regarding electrical, hydraulic, and road infrastructures become difficult to evaluate. The issue of the estimation for the return period of snow events is solved by analysing pairs of rainfall and temperature data. First, the statistical dependence of the three variables (i.e. snow, rainfall and temperature) is analysed. Second, the return period of a selected rainfall sample, with values conditioned to a specific range of temperatures, is evaluated (i.e., indirect snow return period). Then, the corresponding snow return period (i.e., direct snow return period) is estimated. Finally, the equivalence of both return periods is investigated. The results obtained with the two approaches are compared, presenting encouraging perspectives in terms of return period value equivalence