River Forecast Technician, River Forecast Centre, Government of British Columbia, Canada

Speech Title: Potential Impacts of Climate Change on Storm Intensities of Central Alberta

Abstract: Under the effect of climate change, warming likely means that there will be more water vapour in the atmosphere and extreme storms are expected to occur more frequently and with greater severity, resulting in municipal Intensity-Duration-Frequency (IDF) curves with higher intensities and shorter return periods. A regional climate model, the WRF (Weather Research and Forecasting) model, was set up in a one-way, three-domain nested framework to simulate future summer (May to August) precipitation of central Alberta. WRF is forced with climate data of four Global Climate Models, CanESM2, ACCESS1-3, CCSM4, and MIROC5, for the baseline 1980–2005 and 2041–2100 based on the Representative Concentration Pathways 4.5 and 8.5 of Intergovernmental Panel on Climate Change. Due to the bias of WRF’s simulations, a quantile-quantile bias correction method and a regional frequency analysis is applied to derive projected grid-based IDF curves for central Alberta. In addition, future trends of air temperature and precipitable water, which affect storm pattern and intensity, are investigated. Future IDF curves show a wide range of increased intensities especially for storms of short durations (≤1-h). Conversely, future IDF curves are expected to shift upward because of increased air temperature and precipitable water which are projected to be increased by 2071–2100, respectively. Our results imply that the impacts of climate change could increase the future risk of flooding in central Alberta.