More progress on a new painting -- Heavy Cloud (now with a light shower)

I managed to get quite a bit of painting done yesterday including a few hours on this painting whose finish has seemed to elude me. I repainted the sky areas around the clouds and layered some more color in the clouds at the top right. I added some variety and color to the dark mass of trees at the bottom, and I've managed to indicate the light shower of rain starting at the bottom right half. I'm pretty happy with most of the painting now. I think darkening the sky beneath the clouds and added the lighter parts of the trees really helped being the painting together. I want to do a bit more with the darker clouds. The transition from the clouds to the sky isn't quite right and I want a bit different feel in the brushwork. Then a few highlights with the clouds and maybe ill finally be done with this one.