Howling Warpgale

The spell summons driving winds that last
until the start of the the caster's next Magic
phase. Flying creatures may not fly and
must use their basic move. All missile
weapons that roll To Hit suffer a -1
penalty in addition to any other penalties
(long range, etc.). This spell does not affect
Skaven missile weapons, as the unnatural
winds are diverted by the caster himself.