Canadian Forest Service Publications
Spatial models of adjusted precipitation for Canada at varying time scales. MacDonald, H., McKenney, D.W., Wang, X.L., Pedlar, J., Papadopol, P., Lawrence, K., Feng, Y., Hutchinson, M.F., Journal of Applied Meteorology and Climatology (2021) vol. 60.
Issued by: Great Lakes Forestry Centre
Catalog ID: 40333
Availability: PDF (download)
Available from the Journal's Web site. †
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Plain Language Summary
Until twenty years ago, much of Canada’s historical precipitation record had not been adjusted for documented shortcomings related to undercatch, wetting losses, unrealistic snow-water equivalence conversion, and trace amounts of precipitation. This study presents spatial models of adjusted precipitation for Canada at daily, pentad (5-day), and monthly time scales from 1900 to 2015 which correct these known issues. The input data include measurements taken at 3346 stations. We developed 42,331 models for daily total precipitation, 8395 5-day average precipitation models and 1392 monthly total precipitation models. For much of Canada, mapped precipitation values from this study were higher than similar unadjusted models. Error estimates compared favourably to unadjusted models. There was a dry bias in the predictions relative to recorded values of between 1% and 6.7% of the average precipitations amounts for all time scales. Mean absolute predictive errors of the daily, pentad, and monthly models were 2.5 mm (52.7%), 0.9 mm (37.4%), and 11.2 mm (19.3%), respectively. In general, model performance was closely tied to how many stations were available for modeling. The current adjusted models are available in grid form at ~2-10 km resolutions.