This mod adds an improved thunder effect for lightning weather. I higly recommend to use this mod.
The included 1.0 version of Project Thunder is older, but has an included config with adjusted settings to fit my visual mod.

Latest version of Project Thunder (Requires IV-SDK.NET and ClonksCodingLib): https://gtaforums.com/topic/982902-project-thunder/

NOTE: Don't use this mod with the "Disable Lightsprite" option from the "Different Lightsprite options" optional.
      I would highly suggest to use it with my adjusted config file to fit my visual changes.
	  
	  Seems to be compatible with patch 1.0.7.0 and 1.0.8.0 only unfortunately.