When you vote to close a question, are you subscribed to the question? I was going to suggest a feature that automatically posts a "voting to close" comment on a question when the vote is cast so people can ask questions that get sent to the notifications feed of the voter. But then I realized this might already, in effect, happen.
Either way, it took me a while to figure out what to do with silent closure votes. I still find it unintuitive and, if anyone else shares this experience, I think a box under the question would be helpful if it tells the user how to proceed before more votes are cast. Something like "_ has voted to close this question. Comment on this question to ask him/her why before the question reaches five closure votes." would help.