Gridded dropsonde analyses are made using data from the OTREC (Organization of Tropical East Pacific Convection) and PREDICT (Pre-Depression Investigation of Cloud-Systems in the Tropics) projects to characterize the mesoscale properties of tropical oceanic convection in terms of selected thermodynamic parameters computable from the explicit grids of large-scale models. In particular, column relative humidity, low to mid-tropospheric moist convective instability, and convective inhibition correlate with moisture convergence, while sea surface temperature is related to the top-heaviness of mass flux profiles and the integrated entropy divergence. Local (as opposed to global) surface heat and moisture fluxes and convective available potential energy have little relation to these quantities. These results provide useful constraints for cumulus parameterizations.