A combined downscaling-disaggregation weather generator for stochastic generation of multisite hourly weather variables over complex terrain: Development and multi-scale validation for the Upper Rhone River basin

This paper presents a combined downscaling and disaggregation weather generator developed for multisite generation of hourly precipitation and temperature time series over complex terrain. Daily regional weather variables are first generated from Generalized Linear Models based on daily atmospheric circulation indices from NCEP reanalysis. They are then disaggregated to the required spatial and temporal scales using a K-nearest neighbour approach.