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TOC > MSC data > HRDPA Watershed

Data and Products of the High Resolution Deterministic Precipitation Analysis (HRDPA) average watershed precipitation

The Canadian Precipitation Analysis System (CaPA) produces a best estimate of 6 and 24 hour precipitation amounts. This objective estimate integrates data from in situ precipitation gauge measurements, radar QPEs and a trial field generated by a numerical weather prediction system. In order to produce the High Resolution Deterministic Precipitation Analysis (HRDPA) at a resolution of 2.5 km, CaPA is connected to the continental HRDPS for its trial field. CaPA-HRDPA produces four analyses of 6 hour amounts per day, valid at synoptic hours (00, 06, 12 and 18 UTC) and two 24 hour analyses valid at 06 and 12 UTC. A preliminary production is started 1 hour after valid time and a final one is launched 7 hours later. This translates into a production of 12 analyses per day.

For more information on the HRDPA, please refer to this technical note: http://collaboration.cmc.ec.gc.ca/cmc/CMOI/product_guide/docs/lib/CAPA-HRDPA_4_0_0_Tech_note_e.pdf

River flow at a particular location is impacted by precipitation occurring upstream of that location. In order to better interpret changes in observed stream flow, it is useful to compute average precipitation for watersheds defined by the locations where stream flow is being observed.

In collaboration with all provinces and territories, MSC operates an extensive network of stream flow gauges. Historical and real-time flow data is available here: https://wateroffice.ec.gc.ca/

Furthermore, Environment and Climate Change Canada has published the National hydrometric network basin polygons dataset which provides watershed delineations upstream of active hydrometric gauges which report flow. https://open.canada.ca/data/en/dataset/0c121878-ac23-46f5-95df-eb9960753375

By combining these polygons with the HRDPA, it is possible to obtain average watershed precipitation. The Esri Shapefiles described here contain the result of this computation, in millimeters.


How to access the data

This data is available on the MSC Datamart data server service as well as MSC GeoMet:

An overview and examples to access and use the Meteorological Service of Canada's open data is available.


The end-user licence for Environment and Climate Change Canada's data servers specifies the conditions of use of this data.

MSC Open Data Service Usage Policy

The MSC Open Data Service Usage Policy determines what constitutes an acceptable use of MSC Open Data services and provides users best practices for optimal use.


The metadata of the High Resolution Deterministic Precipitation Analysis averaged by watershed are available on the Open Government Portal.

Technical documentation


The chronology of changes to operational systems is available here.