A challenge in reducing severe weather risk is to improve the utilization of model output signatures and indexes of severe weather and convection. The highest resolution operational numerical weather prediction models are still not able to resolve severe weather causing phenomena. It is well known that convergence patterns, often along frontal boundaries and in meso-scale complexes, areas of vorticity advection and vertical motions are regions where the potential for extreme convection events exist on barely resolvable model scales of motion. In terms of the NWP model, the 3-dimensional extent, or volume, of convergence patterns appears to grow and be advected to increased elevation in the NWP models. While this phenomena can not be directly observed with our current observing network, the NWP model suggests that it is a signature for sub-grid scale convective outbreaks. We explore the volume and extent of these convergence iso-surfaces as proxies for severe weather and compare their locations to other severe weather indicators such as Lifted Index. We will verify these results with the NCEP Storm Prediction Center severe weather watches and weather service convective outlook products. Convergence calculated from the motion fields from the Global Spectral Model or the Eta 12 km model will be used. The model data is obtained using NCEP Real Time NOMADS Open-DAP server, also known as DODS, to provide access to archive and real time records, for example, a model predicted severe weather index, such as Lifted Index. The results of the development of our proxy for sub-grid scale severe weather indicator will be shown.