24 tomahawks was the number mentioned by Jcustis in his comment (as an example of what a US strike could be).
I am sure it will be more than 24 in reality.
But really 24 or 48 or 96, it hardly matters. Supposedly the whole point is to "make a point". Can it be made with 13?
There doesnt seem to be any objective beyond covering Obama's A for the "red-line" remark.
Unless, of course, people like me have no idea what grand strategic move is being made here (entirely possible, I must admit).