Blizzard and other 'Wave' spells

[Janifer]

I've always been curious, and am not able to /o at the moment to pose this question, SO:

How do these wave spells, like Blizzard(http://wiki.project1999.com/Blizzard), work exactly?

Do they have a certain amount of waves that must be used up, and will continue to fall on all mobs(max 3 at a time) in the vicinity of the target until the waves have all fallen?

What if only ONE target is in range of the cast? Will it then receive all of said waves(3)?

Thanks!