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TOC > MSC data > HRDPA > HRDPA on MSC Datamart

High Resolution Deterministic Precipitation Analysis (HRDPA) Data in GRIB2 Format

This page describes the High Resolution Deterministic Precipitation Analysis data available in GRIB2 format.

Data location

MSC Datamart 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 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 :

where :

  • polar_stereographic : Grid projection
  • hh : time interval of 06 or 24 hours in which precipitation accumulations are analyzed
  • HH : UTC run time [00, 06, 12, 18]

A history of 30 days is maintained in this directory.

Grid specifications of the grids

  • Polar-stereographic grid

HRDPA grid specification image

Table lists the values of parameters of the polar-stereographic grid.

Parameter Value
ni 2500
nj 1222
resolution at 60° N 2.5 km
coordinates of the first grid point 42.2504° N 131.0928° W
grid orientation (with respect to j axis) -115.0°
  • Rotated lat-lon grid

Rlatlon HRDPA grid

The following table lists the values of various parameters of the rotated lat-lon grid:

Parameter Valeur
ni 2538
nj 1288
resolution at 60° N 2.5 km
coordinate of the first grid point -36.09° N ; 114.70° W

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

File name nomenclature

Polar-stereographic grid

The files have the following nomenclature:

CMC_HRDPA_APCP-TotalPrecipAmount-HHMMcutoff_SFC_0_ps2.5km_YYYYMMDDHH_000.grib2

where :

  • CMC : Data is produced by the Canadian Meteorological Centre (Constant string)
  • HRDPA : High Resolution Deterministic Precipitation Analysis (Constant string)
  • APCP : Analysis of Precipitation (Constant string)
  • TotalPrecipAmountPeriod : Total precipitation amount over a period of time in number of hours (006 or 024)
  • HHMMcutoff : Observation cuttoff time in number of hours and minutes after valid time. (0100cutoff or 0700cutoff)
  • SFC_0 : Level type is Surface and level value is 0 (Constant string)
  • ps2.5km : Projection type is Polar-Stereographic and the resolution is 2.5 km (Constant string)
  • YYYYMMDDHH : Analysis valid time in UTC. YYYY=Year, MM=Month, DD=Day, HH=Hour (ex: 2018020912)
  • 000 : The projection time in number of hours. Always 000 for an analysis product (Constant string)

Example :

CMC_HRDPA_APCP-006-0100cutoff_SFC_0_ps2.5km_2018020912_000.grib2

This file originates from the Canadian Meteorological Center (CMC) and contains data of the High Resolution Deterministic Precipitation Analysis (HRDPA). This is a precipitation analysis (APCP) of 6 hour amounts (006) where the accumulation period goes from 2018020906 to 2018020912. It is considered preliminary because observations have been collected up to 2018020913, which is 1 hour after valid time (0100cutoff). The data is on a polar-stereographic grid at a resolution of 2.5 km (ps2.5km). The valid time of the analysis is 2018020912_000 and the suffix _000 means that the projection time in the future is null, which is always the case for an analysis. The data is encoded in GRIB2 format (.grib2).

Note that a second variable is also included in this file and it is the confidence index for the analysis (CFIA).

Rotated lat-lon grid

Files have one of the following nomenclatures:

  • {YYYYMMDD}T{HH}Z_MSC_HRDPA_{VAR}_Sfc_RLatLon0.0225_PT0H.grib2
  • {YYYYMMDD}T{HH}Z_MSC_HRDPA-Prelim_{VAR}_Sfc_RLatLon0.0225_PT0H.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
  • HRDPA : Constant string indicating that data is from the High Resolution Deterministic Precipitation Analysis. Observation cut-off time is about 007 hours after the time YYYYMMDDHH indicating that a maximum of observations has likely been collected
  • HRDPA-Prelim: Constant string indicating that data is from the High Resolution Deterministic Precipitation Analysis. Observation cut-off time is one hour after the time YYYYMMDDHH indicating that possibly not all observations have been collected
  • VAR : Constant string indicating the variable included in the file namely in this case, the accumulated precipitation which has been analyzed over a specific period [APCP-Accum6h, APCP-Accum24h]
  • Sfc : Constant string indicating that the surface is the vertical level
  • RLatLon0.0225 : Constant string indicating a rotated lat-lon grid with 0.0225 deg resolution (about 2.5km)
  • PT0H : Based on ISO8601 norms. P, T and H are constant character designating Period, Time and Hour. Here PT0H indicates an analysis.
  • grib2 : constant string indicating the GRIB2 format is used

Examples of files names :

  • 20231106T00Z_MSC_HRDPA-Prelim_APCP-Accum6h_Sfc_RLatLon0.0225_PT0H.grib2

The file originates from the Meteorological Service of Canada (MSC) and contains a High Resolution Deterministic Precipitation Analysis (HRDPA). It contains a preliminary analysis of precipitation accumulation represented by the APCP variable over a 6 hour interval. The data are on a lat-lon rotated grid at a 2.5 km resolution (RLatLon0.0225). The analysis was produced on November 6, 2023 at 00Z (20231106T00Z). The 006-hour interval in which the precipitation is analyzed is 2023110600 to 2023110606.

  • 20231106T12Z_MSC_HRDPA_APCP-Accum24h_Sfc_RLatLon0.0225_PT0H.grib2

The file originates from the Meteorological Service of Canada (MSC) and contains a High Resolution Deterministic Precipitation Analysis (HRDPA). It contains a final analysis of precipitation accumulation represented by the APCP variable over a 24-hour interval. The data are on a lat-lon grid rotated to a 2.5 km resolution (RLatLon0.0225). The analysis was produced on November 6, 2023 at 12Z (20231106T12Z). The 24-hour interval in which precipitation is analyzed is 2023110612 to 2023110712.

NOTE: A second variable is also included in this file and it is the confidence index for the analysis.

List of variables

About the polar stereographic grid no-data mask

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

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