An analysis of future trends in extreme precipitation events over several Canadian locations

Abstract

Trends in precipitation and extreme occurrence were analyzed for five locations across Canada using the Canadian Regional Climate Model. Results from the model’s base simulation were compared to those from a future scenario of increased atmospheric CO2. The climatology of nearby weather stations was used to assess the model’s ability to simulate the present and future climate. Other parameters such as 850 and 500 hPa geopotential associated with the most extreme events were analyzed to infer changes in the mechanisms causing such events. The model underestimates annual precipitation along with extreme occurrence and intensity. A wetter, but more variable climate is projected for most locations. Frequency and intensity of extreme events increases at most locations. Simulated extreme events over western locations were found to be associated with cold lows, while eastern events were linked with moisture transport at 850 hPa. Western events were reproduced accurately, whereas eastern ones were not.