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TOC > MSC data > REPS > REPS on MSC Datamart

Regional Ensemble Prediction System (REPS) Data in GRIB2 Format

This page describes Regional Ensemble Prediction System data available in GRIB2 format.

Data location

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 the Meteorological Service of Canada's open data is also available.

This data is available using the HTTPS protocol and resides in a directory that is plainly accessible from a web browser. Visiting this directory with an interactive browser will yield a raw listing of links, each link being a downloadable GRIB2 file.

This data can be accessed at the following URLs:

where :

  • EnsembleDataType : Can be "raw" for individual members direct model output or prob for probabilistic products created from all members
  • HH : Forecast run hour in UTC
  • hhh : Forecast time

A 24-hour history is stored in this directory.

Technical specification of the grid

  • Polar-stereographic grid

REPS grid ps

Values assigned to the parameters of the stereographic polar grid at 15km resolution:

Parameter Value
ni 600
nj 510
resolution at 60° N 15 km
coordinates of the first grid point 19.3206° N 141.5411° W
grid orientation (with respect to j axis) -110.0°
  • Rotated lat-lon grid

Grille du SRPE Rlatlon

The following table lists the values of various parameters of the rotated lat-lon grid at 10km resolution:

Parameter Valeur
ni 908
nj 960
resolution at 60° N 10 km
coordinate of the first grid point 50.76° N ; 20.81° W

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

File name nomenclature

NOTE: ALL HOURS ARE IN UTC.

Polar-stereographic grid at 15km resolution

Files have the following nomenclature:

CMC-reps-srpe-{datatype}_{VAR}_{LVLTYPE}_{LVL}_{resolution}_{YYYYMMDDHH}_P{hhh}_{content}.grib2

where:

  • datatype : Can be "raw" for individual member direct model output or prob for probabilistic products created from all members
  • VAR : Variable name (ex: WIND)
  • LVLTYPE : Level type (ex: SFC for surface, NTAT for the top of the atmosphere, DBLL_10cm for 10cm under the surface, TGL for above ground level)
  • LVL : Level value (ex: 10m for 10 meters)
  • resolution : Grid resolution (ex: ps15km)
  • YYYYMMDDHH : Year, month, and day of the beginning of the forecast and model run in UTC [00, 06, 12, 18]
  • P{hhh} : P is a constant character. "hhh" is the forecast hour [000, 003, 006, ..., 072].
  • FileContent : can be "all-products" or "allmbrs", indicating that all the members or all the probabilistic products for this variable are contained in the file
  • grib2 : Constant string indicating that the GRIB2 format is used

Example of filname: CMC-reps-srpe-prob_TEMP_TGL_2m_ps15km_2021012700_P009_all-products.grib2

Rotated lat-lon grid at 10km resolution

Files have the following nomenclature:

{YYYYMMDD}T{HH}Z_MSC_REPS_{VAR}_{LVLTYPE-LVL}_{Grille}{resolution}_PT{hhh}H.grib2

where:

  • YYYYMMDD : Year, month, and day of the beginning of the forecast
  • T : Time delimiter according to ISO8601 norms
  • HH : UTC run time [00, 06, 12, 18]
  • Z : Time zone (UTC hour)
  • MSC : Constant string indicating the Meteorological Service of Canada, source of data
  • REPS : Constant string indicating that the data is from the Regional Ensemble Prediction System
  • VAR : Variable type included in the file (ex: UGRD). This parameter includes also the statistical measure, if relevant (ex: Accum, MAX, Min). See also the note below.
  • LVLTYPE-LVL : Vertical level type and level value [ex: SFC for surface, AGL-10m for 10m above ground level]
  • Grille : Horizontal grid [RLatLon]
  • resolution : 0.09. Indicating resolution in degrees [0.09°(about 10km)] for latitude and longitude directions
  • PT{hhh}H : Forecast hours based on ISO8601 norms. P, T and H are constant character designating Period, Time and Hour. "hhh" is the forecast hour [000, 003, 006, ..., 072]
  • grib2 : Constant string indicating that the GRIB2 format is used

Example of filename : 20201007T00Z_MSC_REPS_TPRATE-Accum24h_SFC_RLatLon0.09x0.09_PT024H.grib2

Note: Files contain by default all ensemble members. Files containing probabilistic products are identified according to the parameter '-Prob' attached to the variable (ex: 20201007T00Z_MSC_REPS_TPRATE-Accum24h-Prob_SFC_RLatLon0.09x0.09_PT024H.grib2)

List of variables

The variables for the ensemble products available in the GRIB2 files are listed below. Some examples are mentioned for the rotated lat-lon grid at 10km resolution.

  • FPRATE : Freezing rain accumulated over a period. Ex: FPRATE-Accum24h-Prob
  • HEATX : Humidex 2m above ground. Ex: HEATX-Prob_AGL-2m; HEATX-Max24h-Prob_AGL-2m (maximum humidex 2m above ground over a period of 24h)
  • IPRATE : Ice pellets (water equivalent) accumulated over a period. Ex: IPRATE-Accum12h-Prob
  • RPRATE : Rain accumulated over a period Ex: RPRATE-Accum6h-Prob
  • SPRATE : Snow (water equivalent) accumulated over a period. Ex: SPRATE-Accum24h-Prob
  • TEMP / TMP : Temperature 2m above ground. Ex: TMP-Prob_AGL-2m; TMP-Max24h-Prob_AGL-2m (maximum temperature 2m above ground over a 24h period)
  • TPRATE : Total precipitation accumulated over a period. Ex: TPRATE-Max48h-Prob
  • WCF : Wind chill factor 2m above ground. Ex: WCF-Prob_AGL-2m; WCF-Min24h-Prob_AGL-2m (minimum wind chill factor 2m above ground over a 24h period)
  • WIND : Wind speed 10m above ground. Ex: WIND-Prob_AGL-10m; WIND-Max12h-Prob_AGL-10m (maximum wind speed 10m above ground over a 12h period)

The GRIB2 files variables for individual members are the following. The variables are available from 0 to 72h, every 3h. Some examples are indicated for the rotated lat-lon grid at 10km resolution.

  • AFRAIN : Accumulated precipitation in the form of freezing rain
  • ARAIN : Accumulated precipitation in the form of rain
  • AICEP : Accumulated precipitation in the form of ice
  • ASNOW : Accumulated precipitation in the form of snow
  • APCP : Accumulated precipitation, total of all forms
  • SNOD : Snow depth
  • WEASD : Water equivalent of accumulated Snow Depth
  • HGT : Geopotential height ay different pressure levels. Ex: HGT_ISBL-0500, geopotential height at 500hPa
  • RH : Relative humidity at different pressure levels. Ex: RH_ISBL-0010, relative himidity at 10hPa; RH_AGL-2m, relative himidity 2m above ground
  • UGRD : Wind U-component at different pressure levels. Ex: UGRD_ISBL-0700, wind U-component at 700hPa
  • VGRD : Wind V-component at different pressure levels. Ex: VGRD_ISBL-0700, wind V-component at 700hPa
  • TMP : Temperature at different pressure levels. Ex: TMP_AGL-2m, temperature 2m above ground; TMP_ISBL-0050, temperature at 50hPa
  • TCDC : Total cloud cover
  • PRES : Surface pressure
  • PRMSL : Mean sea level pressure
  • TSOIL : Soil temperature 10cm below surface. Ex: TSOIL_DBS-10cm
  • VSOILM : Volumetric soil moisture 10cm below surface. Ex: VSOILM_DBS-10cm
  • LHTFL : Latent heat net flux at surface
  • SHTFL : Sensible heat net flux at surface
  • ULWRF : Upward long-wave radiation flux at the nominal top of the atmosphere. Ex: ULWRF_NTAT
  • DLWRF : Downward long-wave radiation flux at surface
  • DSWRF : Downward short-wave radiation flux at surface

A list in XML format containing for all the 15km grid variables names, a description and the units in both French and English, is available.

About the no-data mask for the polar-stereographic grid

A mask called "No-data" has been added to our GRIB2 encoding process in order to better represent the areas where data are unavailable. This mask only concerns a few grid points with no data, always the same ones, located at the edge of the domain. Note that this mask has no negative effect on the product quality.

Support

If you have any questions about this data, please contact us at: ec.dps-client.ec@canada.ca

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