Ruslan, Sketch 3 is great.
The face of the Wizard MAY be able to slide a little more to the left leaving a little more room to make the cabin a wee bit bigger. If not OK. You did good in any event.
Show the commotion and debris at the base of the storm like you did in the original - with the cow and such.
Some lightning might be good along the back and spine...as the cover is long.
This is a long cover and the bottom part of it which now looks like rolling terrain, needs something. Can you show a path of destruction along the bottom - perhaps more homes, barns, damaged bus, train laying on its side, a swath of destruction through a corn or grain field.
Storms are on occasion green tinged and rampant shades of green, dark blue. I am attaching some images of storms that I find to be striking. If you use the suggestion below with devastation though a corn or grain field, I like the picture that has the green grass. It is a sweet contrast.
Sketch 4 Suggestions
This is good also. I would like to see a draft where the lightning comes out of the top of the Z - it can go off the page.
The lightning on the bottom of the Z has five fingers. Leave the finger closest to the right (near toto). The others extend out and snake into threads of nothing - even try some going off the page.
Free Press - I was interviewed. Indyfest Interview. In closing - Thank you - for a job well done!