This study uses the Big Weather Web (BWW) ensemble---an ensemble developed through a collaborative effort distributed across numerous universities---to evaluate biases in different WRF parameterizations, relative to one another and to observations. The full ensemble includes 48 members at 20-km horizontal grid spacing, with a subset of those members altering only one physical parameterization to allow for controlled intercomparisons. At this grid spacing, cumulus parameterizations are required, along with the usual requirements of boundary-layer, microphysical, and radiation parameterizations. This study focuses on systemic biases of the different parameterizations over approximately two full years of forecasts. For example, different cumulus parameterizations are shown to yield very biases in the vertical structure of atmospheric water vapor, and to a lesser extent temperature, when compared to radiosonde observations. Other biases of this sort, along with speculation as to their underlying causes, will be presented.