What makes my particle system thin out from it's initial density?

It starts out nice and dense but never goes back to it, remaining thin with just a handful of particles at any time

It could be 2 things in my experience.

  1. check that color over life isn’t changing your color or alpha on the particle. It might be adjusting how transparent your particle is.

  2. Given that this is a dark scene with dark clouds, it might be your auto exposure settings. Throw in an unbound post process volume and adjust your settings in there. (maybe set min and max brightness to the same values)

Been messing with it for a while with no effect. Here’s the default as I have had it, anything stand out to you?

Swiss, in cascade (emitter editor) check that color over life node, its alpha is probably set to fade to black.

What is the life time of the particles?
Please post screen shots of the Required, Spawn, Lifetime and Color Over Life modules in cascade.