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 national 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 one 24 hour analysis valid at 12 UTC. A preliminary production is started 1 hour after valid time and a final one is launched 6 hours later. This translates into a production of 10 analyses per day. The domain of the HRDPA is exactly the same as the HRDPS.
For more information on the HRDPA, please refer to this technical note: ttp://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
- Esri Shapefile data available on the MSC Datamart
- Data available via geospatial web services GeoMet-Weather
The end-user licence for Environment and Climate Change Canada's data servers specifies the conditions of use of these data.
The chronology of changes to operational systems is available here.