TOC > MSC data > HRDPS-North > HRDPS-North on MSC Datamart
GRIB2 data from the High Resolution Deterministic Prediction System North (HRDPS-North)
This page describes all the data from the experimental High Resolution Deterministic Prediction System North (HRDPS-North) available in GRIB2 format, i.e. data on a polar stereographic grid at 2.5km resolution and data on a rotated lat-lon grid at 3km resolution over an extended domain.
The 3km-resolution data come from a version of HRDPS-North whose domain and grid are identical to the former Canadian Arctic Prediction System (CAPS) which was implemented during the Polar Forecast Year (YOPP) and whose data were publicly available from January 2018 to November 2021 (see HERE). These data are currently distributed in experimental mode on DD-Alpha, the MSC testing data repository.
NOTE: Weather elements on the grid (WEonG) are only available for the 3km resolution domain.
Data address
MSC Datamart data can be automatically retrieved with the Advanced Message Queuing Protocol (AMQP) as soon as it becomes available. An overview and examples to access and use Meteorological Service of Canada's open data is also available.
The data is available using the HTTPS protocol and resides in a directory that is plainly accessible to a web browser. Visiting that directory with an interactive browser will yield a raw listing of links, each link being a downloadable GRIB2 file.
The data can be accessed at the following URLs:
- Data on 2.5km polar stereographic grid: https://dd.weather.gc.ca/model_hrdps/north/grib2/{HH}/{hhh}/
- Data on 3km rotated lat-lon grid: https://dd.alpha.weather.gc.ca/model_hrdps/north/3km/{HH}/{hhh}/
where :
- HH: UTC run time [00, 12]
- hhh : Forecast hour [000, 001, 002, ..., 048]
A 24-hour history is kept in these directories.
Note: Some weather elements on the grid algorithms ("WEonG") require variable values at t-1, so in order to standardize data supply, forecast times start at 001h.
Technical specification of grids
- Polar stereographic grid
Values given to polar stereographic grid parameters at 2.5km resolution:
| Parameter | Value |
|---|---|
| ni | 1465 |
| nj | 825 |
| resolution at 60° N | 2.5 km |
| coordinates of first grid point | 67.9601°N ; 140.7611°W |
| coordinates (i; j) of North Pole | (389.0, 842.0) |
| grid orientation (relative to j axis) | -116.0° |
- Rotated lat-lon grid
Values given to rotated lat-lon grid parameters at 3km resolution:
| Parameter | Value |
|---|---|
| ni | 2230 |
| nj | 1830 |
| resolution at 60° N | 3 km |
| coordinates of first grid point | 0°N ; 97°W |
Note : The most recent versions of wgrib2 and GDAL support these rotated grids.
Nomenclature of file names
Polar stereographic grid
Files have the following nomenclature:
CMC_hrdps_north_{VAR}_{LVLTYPE-LVL}_{Grid}{resolution}_{YYYYMMDDHH}_P{hhh}-{mm}.grib2
where :
- CMC: Constant character string indicating that the Canadian Meteorological Centre (CMC) is issuing the forecast.
- hrdps : Constant character string indicating that the data comes from the High Resolution Deterministic Prediction System.
- north: Constant character string indicating the north domain.
- VAR: Type of variable contained in the file (e.g. UGRD)
- LVLTYPE_LVL: Vertical level and height [e.g. SFC for surface, TGL_120 for height 120m above ground]
- Grid : Horizontal grid [ps for polar stereographic]
- resolution : 2.5km resolution
- YYYYMMDD: Year, month and day of the beginning of the forecast
- HH: UTC run time [00, 12]
- P{hhh} : "P" is a constant character. "hhh" represents the forecast hour [000, 001, 002, ..., 048]
- mm: Represents the minutes of the forecast [Hard-coded to 00 for now. Time steps of 30 minutes will be available eventually].
- grib2: Constant string indicating that the format is GRIB2.
Example file name:
- CMC_hrdps_north_DEPR_ISBL_0175_ps2.5km_2021092412_P003-00.grib2
Rotated lat-lon grid
Files have the following nomenclature:
{YYYYMMDD}T{HH}Z_MSC_HRDPS-North_{VAR}_{LVLTYPE-LVL}_{Grid}{resolution}_PT{hhh}H.grib2{YYYYMMDD}T{HH}Z_MSC_HRDPS-North-WEonG_{VAR}_{LVLTYPE-LVL}_{Grid}{resolution}_PT{hhh}H.grib2
where :
- YYYYMMDD : Year, month and day of the beginning of the forecast
- T: Time delimiter according to ISO8601 standards
- HH: UTC run time [00, 12]
- Z: Time zone (UTC time)
- MSC: Constant string for Meteorological Service of Canada, the data source
- HRDPS-North: Constant string indicating that the data come from the High Resolution Deterministic Prediction System North
- HRDPS-WEonG: Constant character string indicating that the data originates from the weather elements on the grid ("WEonG") of the High Resolution Deterministic Prediction System North
- VAR: Type of variable contained in the file (e.g. UGRD)
- LVLTYPE-LVL : Vertical level and height [ex: Sfc for the surface, EATM for the integral of the column, DBS-10-20cm layer between 10 and 20cm below the surface, AGL-10m for the height of 10m above ground]
- Grid : Horizontal grid [RLatLon]
- resolution : 0.03. Means a resolution of 0.03° (approx. 3km) in longitudinal and latitudinal directions
- PT{hhh}H: Timing according to ISO8601. P, T and H are constant characters for Period, Time and Hour. "hhh" represents the forecast time [000, 001, 002, ..., 048].
- grib2: Constant character string indicating that the format is GRIB2.
Examples of file names:
- 20231210T00Z_MSC_HRDPS-North_GUST_AGL-10m_RLatLon0.03_PT012H.grib2
- 20231211T12Z_MSC_HRDPS-North-WEonG_VISIFG_Sfc_RLatLon0.03_PT024H.grib2
Variable list
This list contains both the parameters generated from HRDPS-North outputs and the weather elements on the grid (HRDPS-WEonG) calculated in post-processing (only available on the rotated lat-lon grid)
Note: The ventilation index (VI) is currently an experimental parameter.
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