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.