Regional Deterministic Precipitation Analysis (RDPA - CaPA)

The Regional Deterministic Precipitation Analysis (RDPA) based on the Canadian Precipitation Analysis (CaPA) system is on a domain that corresponds to that of the operational regional model, i.e. the Regional Deterministic Prediction System (RDPS LAM3D) except for areas over the Pacific ocean where the western limit of the RDPA domain is slightly shifted eastward with respect to the regional model domain. The resolution of the RDPA analysis is identical to the resolution of the operational regional model RDPS LAM3D . The fields in the RDPA GRIB2 dataset are on a polar-stereographic (PS) grid covering North America and adjacent waters with a 10 km resolution at 60 degrees north.

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.weatheroffice.gc.ca/analysis/precip/rdpa/grib2/polar_stereographic/hh

where:

  • hh:time interval of 06 or 24 hours in which precipitation accumulations are analyzed

File name nomenclature

The file names have the following nomenclature:

CMC_RDPA_APCP-006_SFC_0_ps10km_YYYYMMDDHH_000.grib2
or
CMC_RDPA_APCP-006-final_SFC_0_ps10km_YYYYMMDDHH_000.grib2
or
CMC_RDPA_APCP-024-final_SFC_0_ps10km_YYYYMMDDHH_000.grib2

where:

  • CMC: constant string indicating the data is from the Canadian Meteorological Centre
  • RDPA: constant string indicating the data is from the regional deterministic precipitation analysis (RDPA)
  • APCP:constant string indicating the variable included in this file is in this case the accumulated precipitation which has been analysed.
  • 006 :preliminary 006-hour precipitation analysis. Preliminary analyses do not necessarily have a complete set of observations and are normally available earlier than the corresponding final analysis
  • 006-final :final 006-hour precipitation. Final analyses normally have a complete set of observations and are produced later then the preliminary analyses.
  • 024 :indicates a 024-hour final precipitation analysis prepared using a maximum of collected observations. There is no preliminary analysis for the 024-hour precipitation analysis
  • SFC: constant string indicating the type of level is surface.
  • 0: value of the level type where here 0 indicates surface. For RDPA grib2 data this is the only level available. 
  • ps10km:constant string indicating the projection used is polar-stereographic at 10km resolution.
  • YYYYMMDD: Year, month and day of the beginning time of the analysis.
  • HH: UTC run time [00,06, 12, 18]
  • 000: represents the number of hours after the YYYYMMDDHH time at which the analysis is valid.
  • grib2:constant string indicating the GRIB2 format is used

Example of file name:

CMC_RDPA_APCP-006_SFC_0_ps10km_2011032412_000.grib2

This file originates from the Canadian Meteorological Center (CMC) and contains data of the regional deterministic precipitation analysis (RDPA).

It contains the preliminary analysis of the accumulated precipitation represented here by APCP over a 6 (006) hour time interval starting at 2011032406 and ending at 2011032412. It is considered preliminary because the analysis has been produced before all observations have been collected.

The data is on a polar-stereographic grid at 10km resolution (ps10km).

The file name contains the valid time of the analysis which in this case is 2011032412_000.

The data encoded in GRIB2 format (.grib2).

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

The preliminary 006-hour analysis mentioned above has a corresponding final or complete analysis made using maximum of collected observations. This final analysis is indicated by the word 'final' in the filename. In this case the corresponding final analysis would be: CMC_RDPA_APCP-006-final_SFC_0_ps10km_2011032412_000.grib2 and the valid interval would be the same as defined above.

There is also a 24-hour final analysis produced daily valid at 12Z of that day. In this case a final 24-hour analysis would be named
CMC_RDPA_APCP-024-final_SFC_0_ps10km_2011032412_000.grib2
and it would represent a complete precipitation analysis for the interval from 2011032312 to 2011032412.

Levels

RDPA variables are only available for the surface level.

Data in GRIB2 format