CB cloud convection
 

I have a meteorological question which seems to baffle most of the people I ask.

In regard to a cumulonimbus cloud, there exists a 1000' convective current above the cloud tops in which the updrafts from the cloud penetrate its tops and continue to rise with the momentum they have gained from their ascent through the cloud in the updraft/downdraft zone. Therefore, why is there no more cloud formation in this 1000' area above the cloud where the air is still rising and should theoretically be still condensing?

Thank you

Because this is unsaturated air being displaced by saturated air rising beneath it. This air has to go somewhere.

PM

Because the air becomes sufficiently dry that any liquid moisture carried above the cloud top changes back to water vapour.