I really like this, it looks very abstracty aswell ! I think the fact that the sky went plaid adds to the contrasting effect anyway so it looks like its worked in your favour The effect wouldnt be half as intriguing ( excuse my spelling) if it was a clear blue sky. x
Indeed, washing the sky makes it looks like a line art graphic. I try to erase the mid tone of grays to get the graphic effect by increasing the contrast. Thank you very much for the comment, much appreciated.