Variability at other levels does exist but shows substantially smaller correlation to trends in CAPE than at 1000mb. CAPE analyses is traditionally applied to single soundings and not to GCM grid scale data. Thus the calculations here are more reflective of changes in the mean environment than in single convective cells. If one assumes that convection occurs over 10km horizontal scales and that small scale processes contribute to a normal distribution of temperature fluctuations within each 2.5 degree grid, than the importance of the observed changes in temperature and humidity are compounded due to the nonlinearity of the relationship between CAPE and 1000mb temp. The evolution of clouds type categorized by cloud top pressure over the IFA through large scale westerly wind bursts is shown here .
Low clouds vary only slightly during sustained WWBs.
The deep convective anomalies seen earlier are cause significant changes in surface radiative fluxes. Similarly, changing winds cause heightened surface turbulent fluxes, especially the latent flux of moisture. Magnitudes of these perturbations are of the same order of magnitude, although their phasing is somewhat different as radiative flux perturbations are in phase with thick clouds while turbulent flux perturbations are in phase with high surface winds. These surface winds typically follow the convection by the order of a few days. In addition, heightened radiative fluxes generally preceed increased cloudiness, making their integrated effect less important as the temporal window of analysis is increased.