Related Question: How does each copy of a spell cast to Zada, Hedron Grinder count towards Storm abilities?
If I cast a storm spell that targets only Zada, Hedron Grinder (like Astral Steel) then I will have a copy of it for each of my creatures. However, If spells had already been cast this turn, then I will have more than one copy of the Storm Spell, a nd I could have each copy target Zada. Would the additional copies of the storm spell also trigger Zada's ability, thus giving me more than one copy of the spell per creature?