Exposure

Exposure latitude is enough for average situations, but for this scene: to capture all the drama in the sky as well as not to compromise details of the ground, one will need a bigger sensor of a DSLR. Alternative solution is to take advantage of exposure compensations of K800i. Several frames at different exposure settings can be taken from a fixed point and then united in software. Photoshop's HDR option is quite helpful.

Settings:
exp: 1/640 sec at f/2.8
ISO: 80
meter:CWE