Daily gridded meteorological datasets

The PCIC-Blend gridded dataset combines three existing gridded daily precipitation and temperature datasets:

• PNWNAmet: daily maximum temperature, minimum temperature, and precipitation.
• NRCANmet V2: daily maximum and minimum temperatures.
• NRCANmet-Adjusted: daily precipitation.

PCIC-Blend combines the improved performance of the newer NRCANmet products with the superior ability of PNWNAmet in representing precipitation over western Canada. More information about PNWNAmet and NRCANmet V1 can be found below. 

NRCANmet V2 is an updated version of NRCANmet V1 that uses Adjusted and Homogenized Canadian Climate Data Generation 3 station observations. NRCANmet-Adjusted uses daily precipitation data from the Environment and Climate Change Canada Adjusted Daily Rainfall and Snowfall station data product. In each case, the weather station observations were quality-controlled prior to interpolation.

Using a separate procedure for each variable, the relevant datasets were blended together in their region of overlap (a transition region east of the Rocky Mountains from the Arctic Ocean to the US border) using a sigmoidal weighting function. PCIC-Blend has also been used to calibrate the CanDCS-M6 scenarios on the Statistically downscaled climate scenarios page.

The PNWNAmet dataset provides daily,  gridded data for northwest North America (40°N to 72°N and -169°W to -101°W) at a horizontal resolution of approximately 6 km (1/16°). Station data were available for daily maximum and daily minimum temperature and daily total precipitation, taken from the following sources: 

• Environment and Climate Change Canada's Adjusted and Homogenized Canadian Climate Data (AHCCD) – 2nd generation;
• Homogenized United States Historical Climatology Network (USHCN) in the contiguous US, and;
• Global Historical Climatology Network-Daily (GHCN-Daily) in Alaska.

Selected stations needed at least 40 years of nearly complete records (less than 10% missing days per year from 1945 to 2012). Since few stations were available around the western and northern coasts of Alaska, grid-point data from the 20th Century Reanalysis V2 (20CR2) were used to fill in these gaps. The station data were interpolated using the trivariate thin plate spline interpolation method in the R package fields, with latitude, longitude and monthly climate normals (1971-2000) from ClimateWNA (v5.10) as covariates. A description of ClimateWNA is available in the paper by Wang et al. (2006) under Further reading below. The elevation dependence of PNWNAmet is inherited from ClimateWNA, which used the GEMTED2010 digital elevation model. Precipitation amounts were square-root transformed before interpolation, then transformed back to original units. In a final step, all data were rescaled to match the climatological monthly means of ClimateWNA. The wind data were obtained by re-gridding the 10m wind speed from the coarse-gridded 20CR2 to the same resolution as the temperature and precipitation variables. As a result, the latter do not capture small-scale wind features such as those produced by topography, for example.

PNWNAmet has also been used to calibrate the VIC-GL hydrologic model on the Gridded hydrologic model output page.

Please cite this dataset as:

• Werner, A.T., Schnorbus, M.A., Shrestha, R.R., Cannon, A.J., Zwiers, F.W., Dayon G. and Anslow, F., 2019. A long-term, temporally consistent, gridded daily meteorological dataset for northwestern North America, Scientific Data, 6, 180299, doi:10.1038/sdata.2018.299.

The NRCANmet V1 observational dataset was produced by Natural Resources Canada (NRCan), and provides daily data at a resolution of approximately 10km (1/12°) across Canada. It includes daily minimum and maximum temperatures and precipitation amounts from 1950 to 2012. 

The dataset was created in 2011 by the Canadian Forest Service and updated in 2013. Quality-controlled (unadjusted) station data from Environment and Climate Change Canada were interpolated onto the high-resolution grid using thin plate splines. The number of active stations varied over time, peaking in the 1970s and decreasing thereafter. From 1950 to 2011, the number of precipitation stations ranged from 2000 to 3000, while the number of air temperature stations ranged from 1500 to 3000. Gridding was accomplished using the Australian National University Spline (ANUSPLIN) method, considering latitude, longitude and elevation as covariates.

For further information about NRCANmet V1 and V2, see: 

Hopkinson, R.F., McKenney, D.W., Milewska, E.J., Hutchinson, M.F., Papadopol, P., Vincent, L.A., 2011. Impact of Aligning Climatological Day on Gridding Daily Maximum–Minimum Temperature and Precipitation over Canada. J. Appl. Meteorol. Climatol. 50, 1654–1665. https://doi.org/10.1175/2011JAMC2684.1

Hutchinson, M.F., McKenney, D.W., Lawrence, K., Pedlar, J.H., Hopkinson, R.F., Milewska, E., Papadopol, P., 2009. Development and Testing of Canada-Wide Interpolated Spatial Models of Daily Minimum–Maximum Temperature and Precipitation for 1961–2003. J. Appl. Meteorol. Climatol. 48, 725–741. https://doi.org/10.1175/2008JAMC1979.1

McKenney, D.W., Hutchinson, M.F., Papadopol, P., Lawrence, K., Pedlar, J., Campbell, K., Milewska, E., Hopkinson, R.F., Price, D., Owen, T., 2011. Customized Spatial Climate Models for North America. Bull. Am. Meteorol. Soc. 92, 1611–1622. https://doi.org/10.1175/2011BAMS3132.1

MacDonald, H., McKenney, D.W., Wang, X.L., Pedlar, J.H., Papadopol, P., Lawrence, K., Feng, Y., Hutchinson, M.F., 2021. Spatial Models of Adjusted Precipitation for Canada at Varying Time Scales. J. Appl. Meteorol. Climatol. 60, 291-304. https://doi.org/10.1175/JAMC-D-20-0041.1 

The principal reference for PNWNAmet is: 

Werner, A.T., Schnorbus, M.A., Shrestha, R.R., Cannon, A.J., Zwiers, F.W., Dayon G., Anslow, F., 2019. A long-term, temporally consistent, gridded daily meteorological dataset for northwestern North America, Scientific Data, 6, 180299, doi:10.1038/sdata.2018.299.

To learn more about PNWNAmet’s component datasets and interpolation, see: 

Compo, G.P., and coauthors, 2011: The Twentieth Century Reanalysis Project. Q. J. R. Meteorol. Soc. 137, 1–28. https://doi.org/10.1002/qj.776

Daly, C., Halbleib, M., Smith, J.I., Gibson, W.P., Doggett, M.K., Taylor, G.H., Curtis, J., Pasteris, P.P., Usda, N., 2008. Physiographically sensitive mapping of climatological temperature and precipitation across the conterminous United States.

Danielson, J.J., and Gesch, D.B., 2011. Global multi-resolution terrain elevation data 2010 (GMTED2010) U.S. Geological Survey Open-File Report 2011–1073, 26 p.

Hopkinson, R.F., McKenney, D.W., Milewska, E.J., Hutchinson, M.F., Papadopol, P., Vincent, L.A., 2011. Impact of Aligning Climatological Day on Gridding Daily Maximum–Minimum Temperature and Precipitation over Canada. J. Appl. Meteorol. Climatol. 50, 1654–1665. https://doi.org/10.1175/2011JAMC2684.1

Hunter, R.D., Meentemeyer, R.K., 2005. Climatologically Aided Mapping of Daily Precipitation and Temperature. J. Appl. Meteorol. 44, 1501–1510. https://doi.org/10.1175/JAM2295.1

Nychka, D., Furrer, R., Paige, J., Sain, S., 2017. fields: Tools for Spatial Data. Recently updated (2024) at: https://cran.r-project.org/web/packages/fields/fields.pdf

Wang, T., Hamann, A., Spittlehouse, D.L., Aitken, S.N., 2006. Development of scale-free climate data for Western Canada for use in resource management. Int. J. Climatol. 26, 383–397. https://doi.org/10.1002/joc.1247

For descriptions of the station data used in one or more of these products, see: 

Mekis, É., Vincent, L.A., 2011. An Overview of the Second Generation Adjusted Daily Precipitation Dataset for Trend Analysis in Canada. Atmosphere-Ocean 49, 163–177. https://www.tandfonline.com/doi/full/10.1080/07055900.2011.583910 

Menne, M.J., Durre, I., Vose, R.S., Gleason, B.E., Houston, T.G., 2012. An Overview of the Global Historical Climatology Network-Daily Database. J. Atmospheric Ocean. Technol. 29, 897–910. https://doi.org/10.1175/JTECH-D-11-00103.1 

Vincent, L.A., Wang, X.L., Milewska, E.J., Wan, H., Yang, F., Swail, V., 2012. A second generation of homogenized Canadian monthly surface air temperature for climate trend analysis. J. Geophys. Res. Atmospheres 117, D18110. https://doi.org/10.1029/2012JD017859

Vincent L.A., M.M. Hartwell and X.L Wang, 2020: A Third Generation of Homogenized Temperature for Trend Analysis and Monitoring Changes in Canada’s Climate. Atmosphere-Ocean 58(3):173–191, DOI 10.1080/07055900.2020.1765728

Wang, X.L., H. Xu, B. Qian, Y. Feng and E. Mekis, 2017: Adjusted Daily Rainfall and Snowfall Data for Canada. Atmosphere-Ocean 55(3):155–168, DOI 10.1080/07055900.2017.1342163

This data is subject to PCIC's terms of use. It has been obtained from a variety of sources and is provided as a public service by the Pacific Climate Impacts Consortium. The data is provided by the Consortium on an “AS IS” basis without any warranty or representation, express or implied, as to its accuracy or completeness. Any reliance you place upon the information contained here is your sole responsibility and is strictly at your own risk. In no event will the Consortium be liable for any loss or damage whatsoever, including without limitation, indirect or consequential loss or damage, arising from reliance upon the data or derived information.