Coupled atmospheric-hydrological modelling of the Canadian Rockies rain-on-snow flood of June 2013

Over the last several years there has been some convergence in both atmospheric and hydrological sciences in the application of coupled atmospheric-hydrological modelling systems. In Canada the result of many years of research in academic and government facilities resulted in a prototype hydrology land-surface modelling system know as MESH. Following the devastating floods in Calgary which occurred July 2013, Environment Canada has re-evaluated it modelling systems to look at the ability provide guidance to our partner agencies at the national scale by building upon existing Numerical Weather Prediction technology (NWP) developed largely for weather forecasting applications. The development of these types of guidance systems will rely mainly on the Canadian Precipitation Analysis system (CaPA), the Canadian Land Data Assimilation system (CaLDAS) and the deterministic weather prediction system using the GEM atmospheric model and grund-based real-time flow observations. Preliminary results of our MESH land-surface hydrology scheme forced by GEM forecasted precipitation were evaluated for the specific flood event in and around the headwaters of the Eastern flowing tributaries of the Rocky Mountains. Discussion on model performance, calibration of important water balance and routing parameters along with the feasibility of operationalizing these systems with real-time observational networks is discussed.