Numerical Data from High Resolution Deterministic Prediction System (HRDPS) model - GRIB2 format
The High Resolution Deterministic Prediction System or HRDPS is a set of nested limited-area model (LAM) forecast grids from the non hydrostatic version of the Global Environmental Multiscale (GEM) model with a 2.5 km horizontal grid spacing for the inner domain over five regions. The pilot model of the HRDPS is the Regional Deterministic Prediction System or RDPS (GEM Regional model). The HRDPS is experimental for all but the West domain (not supported 24/7) and its prediction domains are distributed across Canada: East (western Québec and the Great Lakes Basin), West (southern two-thirds of Alberta and British Columbia), Maritimes (Maritime provinces and eastern Québec), Arctic (southern Baffin Island and Hudson Strait) and Lancaster (Arctic archipelago). The fields in the HRDPS high resolution GRIB2 dataset are made available once a day (twice a day for the West domain) on a slightly reduced portion of the five domains, as specified below. Also the forecasts over the Lancaster domain are only available from June to October.
HRDPS access will be as reliable and robust as possible. Users are encouraged to start using and testing the data as soon as possible and see if it suits their needs.
Why use model data with 2.5km resolution?
Users who will benefit most from using these new data are those for whom a detailed forecast of surface temperatures and winds in the present day is important. Especially during the change of seasons and in wintertime when rapid changes in temperature and winds cause phase transitions of precipitation (freezing rain to snow to rain for example), 2.5km forecasts could add much value. Also in the case of short-term forecasts in the presence of complex terrain or along shores, the influence of changes in altitude, topography and nature of the terrain will be better described for phenomena at this scale (lake or sea breezes, local valley flows, phase changes, etc.). Even over less rugged terrain, or over water away from shore, these more precise forecasts could be useful, repeatedly over a long period. As well, for hydrological forecasts on smaller basins, the HRDPS should be considered.
When is the 2.5km resolution model data less useful?
The HRDPS not being equipped with its own data assimilation system, so its quality depends largely on the RDPS, which provides initial and boundary conditions, and on the global data assimilation system acting upstream. So if the forecast of the RDPS is questionable over the region of interest, it is likely that the higher resolution forecast will only magnify the problems of the regional forecast. Also, for forecast lead times of more than 24 hours the use of the regional or global forecasts will be required.
East: experimental
| ni | 762 |
|---|---|
| nj | 570 |
| resolution at 60° N | 2.5 km |
| coordinate of first grid point | 38.7177° N 91.2164° W |
| (i,j) coordinate of North Pole | (445.0, 2240.0) |
| grid orientation (with respect to j axis) |
-80.0° |
There is also a formatted gzipped ASCII file containing geographical coordinates for each grid point.
West: operational
| ni | 685 |
|---|---|
| nj | 485 |
| resolution at 60° N | 2.5 km |
| coordinate of first grid point | 44.6922° N 129.9011° W |
| (i,j) coordinate of North Pole | (578.0, 1900.0) |
| grid orientation (with respect to j axis) |
-113.0° |
There is also a formatted gzipped ASCII file containing geographical coordinates for each grid point.
Maritimes: experimental
| ni | 595 |
|---|---|
| nj | 451 |
| resolution at 60° N | 2.5 km |
| coordinate of first grid point | 41.2405° N 66.1830° W |
| (i,j) coordinate of North Pole | (1078.0, 1867.7) |
| grid orientation (with respect to j axis) |
-36.2° |
There is also a formatted gzipped ASCII file containing geographical coordinates for each grid point.
Arctic: experimental
| ni | 430 |
|---|---|
| nj | 420 |
| resolution at 60° N | 2.5 km |
| coordinate of first grid point | 68.0079° N 82.9299° W |
| (i,j) coordinate of North Pole | (-850.0, 361.0) |
| grid orientation (with respect to j axis) |
-150.0° |
There is also a formatted gzipped ASCII file containing geographical coordinates for each grid point.
Lancaster: experimental (Available roughly June to October inclusive)
| ni | 493 |
|---|---|
| nj | 650 |
| resolution at 60° N | 2.5 km |
| coordinate of first grid point | 66.2515° N 95.2686° W |
| (i,j) coordinate of North Pole | (350.0, 938.0) |
| grid orientation (with respect to j axis) |
-74.84° |
There is also a formatted gzipped ASCII file containing geographical coordinates for each grid point.
Download
The data is available using the HTTP 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. In practice, we recommend writing your own script to automate the downloading of the desired data (using wget or equivalent). If you are unsure of how to proceed, you might like to take a look at our brief wget usage guide.
The data can be accessed at the following URLs:
http://dd.weather.gc.ca/model_hrdps/east/grib2/HH/hhh/
http://dd.weather.gc.ca/model_hrdps/west/grib2/HH/hhh/
http://dd.weather.gc.ca/model_hrdps/arctic/grib2/HH/hhh/
http://dd.weather.gc.ca/model_hrdps/maritimes/grib2/HH/hhh/
http://dd.weather.gc.ca/model_hrdps/lancaster/grib2/HH/hhh/
where:
- HH: model run start, in UTC [06,12,18]
- hhh: forecast hour [000,001,002,...,024] east arctic maritimes
- hhh: forecast hour [000,001,002,...,030] lancaster
- hhh: forecast hour [000,001,002,...,042] west
File name nomenclature
The file names have the following nomenclature:
CMC_hrdps_domain_Variable_LevelType_level_ps2.5km_YYYYMMDDHH_Phhh-mm.grib2
where:
- CMC: constant string indicating that the data is from the Canadian Meteorological Centre
- hrdps: constant string indicating that the data is from the High Resolution Deterministic Prediction System
- domain: constant string indicating which domain that the data is from
- Variable: Variable type included in this file.
- LevelType: Level type.
- Level: Level value.
- ps2.5km: constant string indicating that the projection used is polar-stereographic at 2.5km resolution.
- YYYYMMDD: Year, month and day of the beginning of the forecast.
- HH: UTC run time [06,12,18]
- Phhh: P is a constant character. hhh is the forecast hour [000,001,002,...,024/030/042]
- mm: mm are the forecast minutes [Hard-coded to 00 for now. In the future 30 minute timesteps will be available]
- grib2: constant string indicating the GRIB2 format is used
Example of file name:
CMC_hrdps_east_DEPR_ISBL_0175_ps2.5km_2011092412_P003-00.grib2
This file originates from the Canadian Meteorological Center (CMC) and contains the data of the High Resolution Deterministic Prediction System. The data in the file start on September 24th 2011 at 12Z (2011092412). It contains the dew point depression (DEPR) at the isobaric level 175 mb (ISBL_0175) on a polar-stereographic at 2.5km resolution (ps2.5km) for the forecast hour 03 (P003) and 00 minutes (-00) in GRIB2 format (.grib2).
Levels
Vertical coverage of three-dimensional fields is provided by up to 28 isobaric levels.
Isobaric levels (hPa): 1015, 1000, 0985, 0970, 0950, 0925, 0900, 0850, 0800, 0750, 0700, 0650, 0600, 0550, 0500, 0450, 0400, 0350, 0300, 0275, 0250, 0225, 0200, 0175, 0150, 0100, 0050.
Some fields receive limited three-dimensional coverage of 4 levels in the vertical.
Isobaric levels (reduced coverage, hPa): 0850, 0700, 0500, 0250.
Additional levels that may be applicable to a given parameter are:
- surface
- fixed height above ground
- fixed height below ground
- thickness between two isobaric levels
- nominal top of the atmosphere
- entire atmospheric column
Data in GRIB2 format
- Date modified: