Nice work.
I think its quite good, however when spawns some "particles" it looks a little unnatural, as they seem to appear circular. Maybe its just my PC?
I found it ammusing to ater this setting, watch your computer cringe!
if(m_Particles.size() < 900000000)
I'd say work on where the particles spawn, (perhaps where the player cannot see them, and also see if you can make the travel of the particles much more random, or increase the frequency of the change. Also I think the pauses are too abrupt, and effect a lot of particles at the same time, if this could also be randomised it would appear pretty realistic. Good work.