HRDPS data in 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 one main Pan-Canadian region and two smaller regions in northern Canada: the Arctic (southern Baffin Island and Hudson Strait) and Lancaster (Arctic archipelago) regions. The pilot model of the HRDPS is the Regional Deterministic Prediction System or RDPS (GEM Regional model). The fields in the HRDPS high resolution GRIB2 dataset are made available four times a day for the Pan-Canadian domain for a 48 hour forecast period and once a day for the Arctic and Lancaster domains for a 24 and 36 hour forecast period respectively, as specified below.

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.

Users who will benefit most from using these new data are those for whom a detailed forecast of surface temperatures and winds 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.

The HRDPS not yet 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 magnify the problems of the regional forecast. However, for the Pan-Canadian region, initial cloud and surface data are now provided by a coupled HRDPS-Caldas (Canadian Land Data Assimilation System) cycle, improving clouds, precipitation and surface fields. For forecast lead times of more than 24 hours the use of the regional or global forecasts might be required

Available Domains

Continental: experimental

High resolution geographical grid coverage

Grid specifications
Table lists the values of various parameters of the LAM CONTINENTAL polar-stereographic grid
Parameter Value
ni 2576
nj 1456
resolution at 60° N 2.5 km
coordinate of first grid point 35.6073° N
128.0813° W
(i,j) coordinate of North Pole (840.0, 2296.0)
grid orientation
(with respect to j axis)
-108.0°

There is also a formatted gzipped ASCII file containing geographical coordinates for each grid point.

East: experimental

High resolution geographical grid coverage

Grid specifications
Table lists the values of various parameters of the LAMEAST polar-stereographic grid
Parameter Value
ni 765
nj 570
resolution at 60° N 2.5 km
coordinate of first grid point 38.6985° N
91.3395° W
(i,j) coordinate of North Pole (450.0, 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.

Prairies: experimental

High resolution geographical grid coverage

Grid specifications
Table lists the values of various parameters of the LAMPRAIRIE polar-stereographic grid
Parameter Value
ni 655
nj 570
resolution at 60° N 2.5 km
coordinate of first grid point 41.8344° N
108.4943° W
(i,j) coordinate of North Pole (1015.0, 1869.0)
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

High resolution geographical grid coverage

Grid specifications
Table lists the values of various parameters of the LAMWEST polar-stereographic grid
Parameter Value
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

High resolution geographical grid coverage

Grid specifications
Table lists the values of various parameters of the LAMMARITIME polar-stereographic grid
Parameter Value
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

High resolution geographical grid coverage

Grid specifications
Table lists the values of various parameters of the LAMARCTIC polar-stereographic grid
Parameter Value
ni 585
nj 450
resolution at 60° N 2.5 km
coordinate of first grid point 68.4289° N
90.4431° W
(i,j) coordinate of North Pole (-780.0, 460.0)
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

High resolution geographical grid coverage

Grid specifications
Table lists the values of various parameters of the LAMLANCASTER polar-stereographic grid
Parameter Value
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:

where:

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:

Data in GRIB2 format

What we are doing

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