Particles for rain/snow and Fog?

Hello, i’m getting a grip of particle system, so i thought a way for not to overload the engine for rpg or fps for rain or snow effects. You don’t need the effect on the whole area, but just in the one visible, so you can tie the particle to the camera so it move with the view, and if you want the effect of heavy snow on rain you can use the fog to make the far places blurry.
Is my guess right?

Please name the topic more specific and relevant to your question.

Yes you can combine particles with fog, and you can use Wrap with Wrap Bounds feature to make rain simulated in world space in playable area, and by moving emitter will look still fine and good.