Sub-Basin Precipitation Forecasts from Canada's GDPS Model

Environment and Climate Change Canada provides 7-day and 10-day accumulated precipitation forecasts from the Global Deterministic Prediction System, aggregated by watershed polygon. The data, updated twice daily at 00Z and 12Z, supports flood risk assessment and water resource management. Forecasts are derived from a global numerical weather prediction model running at approximately 15km resolution.

Use Cases

• Identify watersheds prone to flooding by analyzing aggregated precipitation forecasts per sub-basin polygon.
• Support water resource management by using 168-hour and 240-hour cumulative precipitation values for reservoir and irrigation planning.
• Enable emergency preparedness through spatial analysis of forecasted precipitation totals across vulnerable basins.
• Monitor drought conditions by tracking extended 10-day precipitation outlooks aggregated at the watershed scale.

Strengths

• Forecasts are updated twice daily (00Z and —12Z), providing frequent data refreshes.
• Data offers an extended outlook covering both 7-day (168-hour) and 10-day (240-hour) forecast horizons.
• Precipitation values are aggregated by sub-basin polygon, simplifying hydrological analysis.
• Derived from a global numerical weather prediction model with approximately 15km resolution.

Limitations

• Forecast accuracy inherently decreases for longer lead times, especially towards the 10-day horizon.
• Data represents model forecasts, not observed measurements, and may contain systematic biases.
• Aggregation to sub-basin polygons averages out local, high-intensity precipitation variations.

Provenance

Source

Environment and Climate Change Canada (ECCC), via the Government of Manitoba.

Collection Method

Output from the Global Deterministic Prediction System (GDPS) model, aggregated into sub-basin polygons.

Time Range

Forecasts span from day 0 to day 10.

Freshness

Updated twice daily.

Geography

Global model output, aggregated for sub-basins relevant to Canada.