[LVL ED] Outdoor Ideas

[Obliviator27]

Rain is a particle system. Use the rain sound under...general, I think along with it and you should be fine.
Thunder and lighting is a script that flickers a boxlight momentarily, then a sound plays afterwards. Timers are your best bet.
When placing grass, be sure to turn collision off in the second tab.
Mountains are usually very large dirt piles, placed far off.
Use a large boxlight with fairly high values to accurately depict outdoors.

You can call CreateParticleSystemAtEntity more than once.