After the Storm…
These images are from a series of tests I did over the Christmas holidays, cloudscapes rendered in Mental Ray with faked translucency and scattering using falloff and gradient maps. The clouds are created using facing billboard particles scattered over a basic blobby cloud mesh using Particle Flow.
Pete Mc Nally's Blog 
Cool, nice work, & thank you for sharing the creation method 🙂 !
Thanks for checking it out Josh!