GEM (Generation of weather Elements for Multiple applications) : its application in areas of complex terrain

The weather generator model GEM (Generation of weather Elements for Multiple applications) was modified to generate mean daily dew-point temperature and wind speed with other weather elements. Analysis of weather records from three climatological sites in Idaho, USA, showed that the simulated number of wet days per month and amounts of precipitation per wet day, except for September at one site, were representative of historical values. Simulated mean monthly maximum and minimum temperatures were within 2.9°C, mean annual temperatures were within 0.2°C and dew-point temperatures were within 1°C of historical values. Simulated mean monthly solar radiation varied as much as 15% from historical values, but most were within 10%. Generated mean monthly and annual wind speeds were nearly all less than 0.5 m s -1 different from historical values. Except for some mean monthly minimum and dew-point temperatures, the standard deviation computed from simulated monthly and annual records was less than those computed from historical records.