Inspired by this mod:
http://www.fallout3nexus.com/downloads/file.php?id=1293
To install: drop the esp in your data folder, place a checkmark beside the plugin using FOMM or FONV launcher.
To uninstall: remove the esp from the data folder.
That's it
There will be conflicts with any other weather mods, so it should be placed near the bottom of your load order to work properly.
Mods used for the screen captures:
NMC (Awesome) Texture Pack
http://www.fallout3nexus.com/downloads/file.php?id=12056
Anime SunGlare
http://www.newvegasnexus.com/downloads/file.php?id=35243
Detailed Normals - Texture Pack
http://www.newvegasnexus.com/downloads/file.php?id=38196
ENBseries
http://www.tesnexus.com/downloads/file.php?id=29578
But i would recommend using Tapiok's Enhanced shaders since it does the same and even more
http://www.newvegasnexus.com/downloads/file.php?id=34868