But how much can Yellen really signal?

If the Fed wanted to hold and signal that December was likely for a hike, how would they do it?

The Fed can't pre-commit so it's a communication problem. They will need to preserve some flexibility and will not want to signal a November hike 6 days before the election.

So they really need to sit and watch and wait until after the election.

So my guess is that the first move will be US dollar weakness. But given the quick USD rebounds from weak data in the past month, it won't be held down for long.