My clouds are dynamically lit and also have in-scattering, I have normals for the clouds which are computed in the pixel shader during rendering.
My lighting calculations aren't finished though (it's only a few hours work) so there maybe some lighting requirements I'm missing?
Could it be lack of self-shadowing and maybe not using exponent on the noise, which is creating very wispy looking clouds in your screenshot? Though obviously sometimes wispy clouds are desirable, they often don't look very volumetric.
My go to resource for cloud rendering is a rather old thread here on gameDev by Yann-L, sadly the pictures are all missing now, but they looked impressive at the time and i'm pretty sure the techniques are still in use today. Though the site redesigns have made the posts harder to follower (quote blocks seem to have been lost and so a reply and quote all flows together), there is still plenty of good information to be found in Yann's posts, probably worth a read.
Yann's work was pretty amazing. These days this is probably the best paper I've seen on sky rendering: http://www.hpi.uni-potsdam.de/fileadmin/hpi/FG_Doellner/publications/2012/MED12/paper_1056_cr.pdf
Here's the video: https://www.youtube.com/watch?v=t8ibsEl0kAI
The clouds are based on a Game Programming Gems article that traces rays through a heightfield. The results are pretty convincing.