This webcast introduces the forecaster to the new multiple-forecast-center North American Ensemble Forecast System (NAEFS). Beginning with a brief review of the theory behind ensemble prediction, this presentation then introduces the elements of the NAEFS. These include the U.S. National Centers for Environmental Prediction’s Global Ensemble Forecast System (GEFS) and the Canadian Meteorological Center’s Ensemble Forecast System (CEFS). A description of each separate ensemble system is followed by a discussion of how the NAEFS improves the ensemble forecast over either the GEFS or CEFS alone. Next, the post-processed statistical products from the NAEFS are described, with examples, and some caveats are provided about their use. Finally, cold and warm season case examples are presented in the final section.
Recall why we use ensemble forecast systems (EFSs)
List the ensemble prediction systems the NAEFS is built from and their characteristics
List the characteristics of the EFSs used to create NAEFS
Explain why NAEFS performs better than the EFSs comprising it
Find NAEFS products and data available for download or viewing on the internet
Effectively use NAEFS products in forecasts for your local area
Ensemble, multimodel ensemble, ensemble prediction, ensemble prediction systems, NAEFS, North American Ensemble Forecast System, NCEP Global Ensemble Forecast System, GEFS, Canadian Meteorological Center Ensemble Forecast System, CEFS, bias correction, webcast, ensemble products
August 2020 - The lesson was updated to current internet standards (mp4/html5), with no changes to content.
July 2014: This webcast covers the NAEFS as it was configured in 2009. Each ensemble prediction system (EPS) in the NAEFS has since been upgraded, so skill scores in the webcast are higher. Skill scores still improve from combining the GEFS and CEFS into the NAEFS, however. Some links to products are either no longer active or no longer updated. The list of available data on AWIPS omits products made available since 2009. Case studies are still valid, but some related caveats may not be, because of EPS improvements. Summary points related to the differences noted above are not valid.
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