Rockhound,
the radar will not show "dense clouds".
Radar reflects best of water in the liquid state, very lightly of ice (hardly detectable) and not at all off of vapour.
As stated above, you need to actively scan the sky by moving tilt up and down, to hit the part of the cloud that contains the liquid water.
And the airbus I flew had a Turbulence mode on the radar, a rather unreliable gadget that was supposed to indicate areas of turbulence (in magenta), but usually did so inside a cell. And as one doesn't fly into the cell knowing that turbulence exists inside, the information was generally useless.
Don't ask me how the technical part of that radar worked, I have forgotten and don't have access to the manuals anymore...
Nic
PS: And, Rockhound, there is no CAT inside a cloud - ever. CAT stands for CLEAR air turbulence and is the term for turbulence OUTSIDE of clouds. Everybody who flies knows it is ALWAYS turbulent inside cumuliform clouds, it's just the nature of these things, it is how they are created...