The data included in this study are associated with severe weather events east of the rockies during the fall of 2003 through the summer of 2004. The data base includes cases where: 1) surface-based thunderstorms initiated along a synoptic boundary, 2) the storms produced one or more reports of large hail, damaging wind, and or tornadoes, and 3) the 0-6 km AGL vertical shear was 30 kt or greater. Data used to populate the database was collected from observed or RUC model proximity soundings, radar, satellite, surface observations, and objective analyses based on a combination of RUC and observed data. Preliminary results suggest that several atmospheric variables appear to show some skill in determining how storms will evolve once initiated along a synoptic boundary. The orientation of the mean wind and vertical shear in the 2-6 or 2-8 km AGL layer, with respect to the initiating boundary, appears to demonstrate the best skill. Using this information, a normalized mode parameter has been developed that incorporates the individual parameters that exhibit the most discrimination skill. Based on the preliminary results, values of the mode parameter greater than 1 suggest that storms are more likely to remain discrete within the first few hours after initiation. Values less than 1 suggest that storms are more likely to evolve into lines or mixed modes involving line and discrete cells. The relatively small size of the initial database (less than 40 cases) currently limits the statistical significance of the results, but more robust results are anticipated as additional cases are collected.