Put weather into a Three.js scene that reads as weather — rain anchored inside the frustum, a storm that is the rain leaned on rather than a second system, lightning on its own light with thunder scheduled by distance, snow that blows up into blizzards and keeps settling until the ground goes white, wet ground with puddles and splashes, and looping ambience that has no seam. Use for scene atmosphere, seasonal states, hero backdrops, or any world where clear/rain/storm/snow needs to be a control the viewer can turn.