Help w/Supernatural phenomina and fantasy weather

[Aramax]

Hi I've been looking for (see title) for quite sometime,does anybody have any ideas or know of a splat book?
For example:
Mercy storm-clouds randomly shoot lightning that heals 2d8 points(D&D)

 

[Ltheb Silverfrond]

I once tried to create a 'master weather table' for random weather. Here are some of the more extreme:
Meteor Showers. (With Meteor Swarm meteors.)
Marsh Fog. (Equivalent to a Cloud Kill)
Richtor-Scale-11 Earthquakes. (Pretty much the 'end of the world'-type earthquake. Easily annihilates anything on the ground)

And I misread your 'mercy storm cloud' as 'Mercury storm cloud'. Thats quite an interesting rain storm there.