It's rough (since I literally threw it together in a few minutes); the Lores are from WHFB, not WFRP, and it's never seen use at the table... but it's a start. Furthermore, several of these lores are not, I think, actually represented in WFRP. That's cool, though: a appropriate situations'll present themselves for their use or they won't.
Roll d10 to determine what Wind is in ascendancy.
|3||Azyr||Heavens||Chaos, Orc & Goblin,||High|
|6||Aqshy||Fire||Orc & Goblin, Skaven||Dark|
|0||Storm (All Lores)|
Rune magic, rituals and such should probably not be affected. Petty Magic either isn't significant enough to be affected, or should be affected regardless of the roll.
Roll d10 to determine the strength of the ascendant Wind. All other Winds and lores work normally. There's probably a lot of room for refinement here, mind you.
|1||Becalmed - Cast as if Mag = Mag-1 (min 1)|
|6-8||Strong - Roll 1 extra casting die, drop 1 casting die|
|9||Dangerous - Must cast at full Mag|
|0||Tempestuous - Must cast at full Mag+1|
Thoughts? I'm not likely to use it any time soon: stuff's getting Weird in my game, but it's not going to run weird in this particularly direction.