Solar energetic proton (SEP) events in the vicinity of Earth have the potential of affecting the performance of civilian, military, and research satellites, including such diverse functions as communications, spacecraft operations, surveillance, navigation, and life support systems. The National Oceanic and Atmospheric Administration's (NOAA) Space Environment Center and the U. S. Air Force Weather Agency cooperate to provide advance warnings of SEP events. Their explicit duties include the need to continually upgrade and improve the accuracy, timeliness, and scope of SEP forecasts. Previous work on this topic established the empirical connection between SEPs and low-temperature X-ray flares. The main focus of the present work is to improve the quality of SEP forecasts by enhancing the size and content of the flare database used to quantify the probability model, tuning the model with imposed operational constraints, and augmenting each SEP prediction with an estimate of the magnitude of the particle event itself.