An electronic bulletin has recently been developed for presenting national and regional temperature and precipitation analyses in Canada. The Climate Trends and Variations Bulletin (CTVB) is a preliminary Internet report which places the most recent season or year in an historical context. This bulletin uses a database created from a combination of the Historical Canadian Climate Database (HCCD), some archived data from the National Climate Data Archive (NCDA), and near real time data from synoptic weather stations. The HCCD contains historical datasets which have been gap filled and homogenized for 131 Canadian stations. Some quality control has been performed on archived and near real time data, however, analyses and rankings may change as the final data become available.
Average temperature and total precipitation are analysed with respect to 11 broad climate regions and for the country as a whole. Annual and seasonal departures from the 1951-1980 reference period are obtained at individual stations, which are rolled up into regional and national time series, in degrees Celsius for temperature, and in percent departures for precipitation. Contour maps, time series and tables of rankings are presented for the current season and are highlighted by accompanying text.
The CTVB can serve both public and scientific interests. It provides a useful tool to visualize patterns and trends in the data, and can be used to determine how global climate events, such as this past El Nino event, have affected the climate in Canada. As a document published on the Web, the CTVB continues to change in content and format as new research initiatives and results become available.