A simple concept, but brilliantly pulled off. To paint such an act of nature and to give it life shows great talent and passion. I could imagine myself walking towards this ominous cloud, and I would think what dangers lay ahead on my path. Exceptional work, keep it up.
Wow, I agree with the general sentiment of the rest of the comments that the colours in this are great! The ruddy hues are really attractive, I haven't seen this kind of dark, warm palette used much in a lot of art. Using a palette to evoke almost a temperature like this is really a difficult thing to get down pat, which you've done wonderfully. Keep up the great work!
The colors make this piece. I like the mood, the rusty oranges with hints of blue to complement them plus the depth the big shadowy part at the bottom of the cloud add a lot of depth. It's impressive how you got so much out of such a small pool of colors. It's all about the atmosphere!