Detail this asset from Unity Store: Original Link
This is a paid asset, but now you can download THOR Thunderstorm Free.
THOR Thunderstorm v1.2 (Latest version)
THOR Thunderstorm is the fastest, most user friendly, best looking and sounding thunder and lightning system you can get. It integrates into your project by simply dragging a prefab into your scene. It gives you everything between light thunder rumbling to the most apocalyptic thunder and lightning strikes you have ever seen in Unity.
• Automatic spawning of lightning
• Spawns randomly, in camera view or both
• Animated Lightning Bolts
• Animated Sheet Lightning
• Lightning Evolution
• Dynamic Spotlight with Shadows (optional)
• 26 High Quality Thunder Samples in 4 Distance Categories
• 3 Background Thunder Loops
• Automatic Pooling
• Zero Garbage Collection
• Very Low Overdraw
• High Compatibility
• Tidy Custom Inspector with Tooltips
Unlike procedurally generated lightning assets, THOR thunderstorm relies on simple shader tricks, clever texturing & modeling, and smart scripting to achieve its blazing fast performance, great looks, and sounds.
THOR Thunderstorm is used in the “Made With Unity” game D.R.O.N.E.
Note: Thor Thunderstorm is not a complete Weather System, it focuses on Thunder and Lightning only and excels in that field. It can be integrated easily in existing weather and sky solutions.