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TOC > MSC data > HRDPS > Experimental HRDPS on DD-Alpha

Experimental High Resolution Deterministic Prediction System (HRDPS) 1 km West data in GRIB2 format

In the summer of 2017 British Columbia was experiencing severe wildfire. To provide more detailed weather information and pilot the air quality models, HRDPS 1 km west domain was implemented in operations in experimental mode on 31 July 2018.

This prediction system uses the Global Environmental Multi-scale Model (GEM). The horizontal grid spacing is approximately 1 km and there are 62 vertical levels with lid nesting.

The lowest momentum level is at an altitude of approximately 40 m. This system is “piloted” by HRDPS 2.5 km national domain, which provides initial, lateral and upper boundary conditions for the atmospheric fields. The initial surface conditions are provided by the 2.5 km Canadian Land Data Assimilation System (CaLDAS) which is coupled to the HRDPS 2.5 km. The initial hydrometeor fields are “recycled” from the 6-h forecast of the HRDPS 2.5 km integration.

Since the original implementation of the HRDPS 1 km west, the system has been running 2 times per day initialized at 00, and 12 UTC and integrated for 48h. This product contains raw numerical results of the system. The Geographical coverage of the system is the most part of British Columbia and Western Alberta. Data are available at a horizontal resolution of 1 km with 62 vertical levels.

Data location

MSC testing data repository DD-Alpha data can be automatically retrieved with the Advanced Message Queuing Protocol (AMQP) as soon as they become available. An overview and examples to access and use the Meteorological Service of Canada's open data is also available.

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.

The data can be accessed at the following URL:


  • HH: Model run start, in UTC [00, 12].
  • hhh: Forecast hour [000, 001, 002, ..., 048]

A 24-hour history is stored in this directory.

Available domain

Image de la grille ouest du domaine 1km du SHRPD

Table lists the values of various parameters of the rotated lat-lon grid over the West domain.

Parameter Value
ni 1330
nj 1180
resolution at 60° N 1.0 km
coordinate of first grid point (with respect to the used grid) 5°S 23°W

Note : The most recent versions of wgrib2 and GDAL support these rotated grids.

File name nomenclature


The files have the following nomenclature:



  • 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.
  • west: Constant string indicating the West domain.
  • Variable: Variable type included in this file.
  • LevelType: Level type.
  • Level: Level value.
  • Grid : Horizontal grid [rotated_latlon].
  • Resolution : Resolution in degreee 0.009x0.009 (about 1km) in latitude and longitude directions.
  • YYYYMMDD: Year, month and day of the beginning of the forecast.
  • T : Time delimiter according to ISO8601 norms.
  • HH: UTC run time [00, 12].
  • Z : Time zone (UTC hour).
  • Phhh: P is a constant character. hhh is the forecast hour [000, 001, 002, ..., 035, 036].
  • 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:


This file originates from the Canadian Meteorological Center (CMC) and contains the experimental West data of the High Resolution Deterministic Prediction System. The data in the file start on August 25th 2019 at 12Z (20190825T12Z). It contains the dew point depression (DEPR) at the isobaric level 175 mb (ISBL_0175) on a rotated lat-lon grid at 1 km resolution (rotated_latlon0.009x0.009) for the forecast hour 03 (P003) and 00 minutes (-00) in GRIB2 format (.grib2).


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

List of variables

This list contains both the parameters generated from the HRDPS outputs and the weather elements on the grid (HRDPS-WEonG) calculated in post-processing, which will soon be available.


If you have any questions about this data, please contact us

Announcements from the dd_info mailing list

Announcements related to this dataset are available in the dd_info list.