Field investigations, VORTEX '99 and MOCISE 2000, addressed questions pertaining to convective initiation. Emphasis was placed on the Great Plains Dryline (DL). Two primary objectives provided focus for the project: 1. Obtain mesoscale data documenting surface and boundary layer thermodynamics during the evolution of the DL. 2. Obtain data documenting coherent flow structures and moisture gradients along the DL. The moisture transition zone across the DL is highly variable, comprised of a series of moisture gradations ranging in spatial increments of 20-30 km down to mere tens of meters. The largest dewpoint differential across the dryline sampled by a mobile mesonet was 10°C 185 m^-1, with an associated theta-e differential of 15K. Additionally, the mobile mesonet data resolved numerous surface mesoscale circulations along the DL. Of interest, the vortices were sampled concurrently with a strengthening of dewpoint differentials as well as a deceleration of DL movement to nearly stationary. This work is being conducted to better understand convective initiation as preliminary activity prior to IHOP.