1. Short-term water level forecasts for the Laurentian Great Lakes using coupled atmosphere, land-surface and lake models Vincent Fortin 1, Murray Mackay 1, Mercè Casas-Prat 1, Frank Seglenieks 2, Sarah Dyck 2, Frédéric Dupont 2, François Roy 1, and Gregory C. Smith 1 1 Meteorological Research Division, Environment Canada 2 Meteorological Service of Canada, Environment Canada European Geosciences Union General Assembly 2015 Vienna | Austria | 12 – 17 April 2015 EGU.eu

2. 2 Outline Environment Canada's weather and environmental prediction systems Improving weather and lake level forecast skill through two-way atmosphere-lake coupling Skill of 48-h water level forecasts over the Great Lakes Extending the lead time to 30 days Summary and future work

3. 3 Environment Canada's weather prediction systems A suite of prediction systems based on the GEM atmospheric model GEPS: 16 days GDPS: 10 days GEPS: 32 days, 60 km, 20 member ensemble global, 1 run/week 60 km, 20 member ensemble, global, 2 runs/day 25 km, deterministic, global, 2 runs/day REPS: 3 days, 15 km, 20 member ensemble, North America, 2 runs/day RDPS: 2 days, 10 km, deterministic, North America, 4 runs/day HRDPS: 2 days, 2.5 km, deterministic, Canada, 4 runs/day Pan Am: 1 day, 250 m, deterministic, Greater Toronto Area, 1 run/day 32 days Operational

4. 4 Gulf of St. Lawrence Prediction System GEM RDPS (10 km) atmospheric model with ISBA land-surface model NEMO+CICE (5 km) ocean-ice model GEM GDPS (25 km) atmospheric model See poster EGU2015-6866 by Pellerin et al.: Evaluation of a new Gulf of St. Lawrence coupled environmental prediction system based on the GEM atmospheric model and on the NEMO-CICE ocean-ice model See poster EGU2015-6866 by Pellerin et al.: Evaluation of a new Gulf of St. Lawrence coupled environmental prediction system based on the GEM atmospheric model and on the NEMO-CICE ocean-ice model

5. 5 Great Lakes Prediction System Dupont et al. (2012) Water Quality Research Journal of Canada WATROUTE routing model GEM RDPS (10 km) atmospheric model with ISBA land-surface model NEMO+CICE (2 km) ocean-ice model Pan Am demo: 250 m weather forecast for Greater Toronto Area GEM GDPS (25 km) atmospheric model

6. 6 Great Lakes watershed and domain of Pan Am demo Lake Superior Lake Michigan Lake Huron Lake Erie Lake Ontario Chicago (Calumet Harbor) Harbor Beach Buffalo / Niagara Falls Toronto 250 km Toledo Stannard Rock Lighthouse Marquette

7. 7 Lake Superior supplies June 2004 - Dec 2009 Overlake evaporation prediction Deacu et al. (2012) Journal of Hydrometeorology Stannard Rock location, Lake Superior Hourly latent heat flux at Stannard Rock (6-18h forecasts, dec. 2008) Observed flux (eddy cov.) Forecasts: Atmos. model (op. config) Lake model (improved flux param.) Matching fluxes in atmos. & lakes Observed supplies (change in storage + outflow) Watershed simulation: Based on operational config. With precipitation analysis Improved flux param. for lakes Matching fluxes in atmos. & lakes

8. 8 2 1 0 -2 Impact of coupling on winter 2014 2m temperature forecasts 32103210 Bias improved by 1C at night, 0.5C during the day Standard deviation improved by 0.1 C Uncoupled atmospheric forecastCoupled forecast

9. Environmental Prediction Applications of the Great Lakes Prediction System Surface current and temperature forecasts Search and rescue Particle tracking (drifting boat, oil spill) Water temperature [C]Surface currents [m/s] Summer of 2008 (system running daily since the fall of 2014) Water level forecasts Storm surge and coastal inundations Optimization of hydropower production

10. How well can we forecast wind-driven anomalies in water level? Source: Ohio Department of Natural Resources http://geosurvey.ohiodnr.gov/ A week in the life of Lake Erie

11. Forecast issued on Oct 30 th, 2014 for Chicago Forecast issued On Oct 31 th Obs. Model 0h 24h 48h +80 cm +60 cm +40 cm +20 cm +80 cm +60 cm +40 cm +20 cm Obs. Model Storm surge forecast for Chicago

12. Storm surge forecast for Chicago: beyond the first peak Observed water level EC forecast 00-24h forecast 24-28h forecast US NOAA forecast 00-24h forecast 24-28h forecast

13. Seiche forecasts for Buffalo Environment Canada's Great Lakes Prediction System (NEMO ocean model, 2-km resolution) U.S. National Weather Service Great Lakes Operational Forecast System (POM ocean model, 5-km resolution) Observed water level 00-24h forecast 24-28h forecast Observed water level 00-24h forecast 24-28h forecast

14. 1.9 cm 3.1 cm 3.2 cm 4.9 cm 5.4 cm 8.6 cm 8.2 cm 10.1 cm RMSE do not significantly increase over time: longer deterministic forecasts possible? RMSE as a function of lead time: analyzed period Oct 23rd – Dec 7th 2014

15. 15 Towards a Great Lakes Ensemble Prediction System WATROUTE routing model (1km) GEM REPS (15 km) atmospheric model with improved land-surface model (SVS) NEMO (2 km) ocean model Monthly outlook, 20 members GEM GEPS (60 km) atmospheric model See poster At CGU/AGU spring meeting in Montreal next month! See poster At CGU/AGU spring meeting in Montreal next month!

16. 16 Summary and Future Work Long-term water level prediction very sensitive to coupling strategy between atmosphere and lakes –flux coupling required in order to close the water balance –but better fluxes also lead to better weather forecasts Skillful forecasts of water level anomalies caused by wind stress can now be obtained two days in advance At longer time scales, tributary flow becomes more important, hence precipitation and snowmelt –will require an ensemble prediction framework