Since she didn't have a how to on this design I took on the task of creating a step by step on how I was able to achieve this affect...
I used a medium blue in the top of my nail down to about 1/2 of my nail.
With a lighter blue I painted the other 1/2 of my nail
With the darker color I sponged a cross the middle of the 2 colors to blend.
Then I did the same with the lighter color to achieve a better blend
Again with a piece of sponge I added white patches to create the clouds.
With a dotting tool I used black & gray polish and semi blended it together to create the shadows in the clouds. I left a little of the polish darker to go under the gray.
And there you have It!
Colors I used:
Pure Ice "French Kiss"
OPI "No room for the Blues"
Sally Hansen "Wet Cement" & "Black Out"
Sinful Colors "Snow me White"