Nice capture of the clouds and careful composition. It doesn't quite grab me though. Maybe in black and white and taken from a more dramatic point-of-view? If you had gotten low to the ground and shot up at the post it would have created a very different mood and a bit more interest for me.
A rather broad interpretation of the challenge, I would think, but maybe that's acceptable; I'm rather new at this. Anyway, it's a nice picture, clear and colorful, and definitely shows the need for rain.
A strong composition, and catches some of that feel of approaching rain after a long dry time. The structure that the post and wire lends to the scene is essential.
Not bad, I probably would crop out most of the ground, to make the viewer focus on the sky (and the probability of rain). I think I know what you tried to go for, that is, showing the dry land waiting for the rain, but I think that cool looking sky needed a bit more "space" in the pic.