A Comparison of Temperature–Precipitation Relationships from Observations and As Modeled by the General Circulation Model of the Canadian Climate Centre

Abstract

A simple temperature and precipitation relationship, as obtained from observed daily values for Canadian stations, has been compared with the relationship produced by the Canadian Climate Centre second-generation climate model. In the winter, over broad areas, the model and the observations agree, both showing more precipitation when the average daily ?screen-level? temperature is warmer than the median daily value. The observations show that more precipitation falls on days that are cooler than normal throughout most of the country in warmer seasons, and in the lee of the Rocky Mountains year-round. However, the model only rarely predicts more precipitation with cooler temperatures, which suggests that parameterization schemes in this model could be improved. This method of comparing observations and model results using a relationship among several important variables has significant value, and it could be applied to other models.