Using a spectral-type cumulus parameterization that includes moist downdrafts within a three-dimensional mesoscale model, various disparate closure assumptions are systematically tested within the generalized framework of dynamic control, static control, and feedback. Only one assumption at a time is changed and tested using a midlatitude environment of severe convection. A control run is presented, which shows good agreement with observations in many aspects. Results of the sensitivity tests are compared to observations in terms of sea level pressure, rainfall patterns, and domain-averaged bias errors (compared to the control run) of various properties. The dynamic control is the part that determines the modulation of the convection by the environment. It is shown that rate of destabilization, as well as instantaneous stability, work well for the dynamic control. Integrated moisture convergence leads to underprediction of rainfall rates and subsequent degrading of the results in terms of movemen... Abstract Using a spectral-type cumulus parameterization that includes moist downdrafts within a three-dimensional mesoscale model, various disparate closure assumptions are systematically tested within the generalized framework of dynamic control, static control, and feedback. Only one assumption at a time is changed and tested using a midlatitude environment of severe convection. A control run is presented, which shows good agreement with observations in many aspects. Results of the sensitivity tests are compared to observations in terms of sea level pressure, rainfall patterns, and domain-averaged bias errors (compared to the control run) of various properties. The dynamic control is the part that determines the modulation of the convection by the environment. It is shown that rate of destabilization, as well as instantaneous stability, work well for the dynamic control. Integrated moisture convergence leads to underprediction of rainfall rates and subsequent degrading of the results in terms of movemen...