http://i476.photobucket.com/albums/rr125/Exmorbis/1289981757804.jpg

The lighting and textures look amazing. Which mods are used in this picture?

Best guess on the weather. Pic is a little small.

http://www.fallout3nexus.com/downloads/file.php?id=8069
http://www.fallout3nexus.com/downloads/file.php?id=10607
http://www.fallout3nexus.com/downloads/file.php?id=12056

Along with the mods in the previous post, it might also be something like fellout
http://www.fallout3nexus.com/downloads/file.php?id=2672

Fellout is a mod that overhauls the lighting in Fallout 3 including making the nights darker. The fellout page shows other lighting mods that work with Fellout. Like ghoulsrpeople2 said, it's hard to tell based on one picture like that.

No, you can actually see [censored] so it's not fellout.
It's dynamic weather.