Two data sets (OTREC and PREDICT) and the European Center operational model are used to study convection.

Vertically integrated moisture convergence is taken to be a proxy for convection. The interplay between the thermodynamic parameters is examined for weak and strong convection. It is found that for strong convection saturation fraction anti-correlates with instability index and DCIN in a similar manner for all analyzed regions of PREDICT and OTREC.

The European Center model is used to look at the composite diurnal cycles of strong and weak convection. As convection increases, saturation fraction increases while instability index and DCIN decrease as in OTREC and PREDICT. The boundary layer and free troposphere thus both play an important role in convection development.