Ability to search when scrolled down the page

I find that when I'm scrolling through the posts I sometimes have a thought for new post I want to create, but then I don't want to create a new post if there's a post that already exists, so I actually first want to do a search. But with the current UI there's no one-click way to do that, I have to scroll back up to the top of the page to do the search, but then I've lost my place on the current page.

I've seen in other products they have a search button in the stick header and that seems like an obvious solution, but perhaps you have other ideas for how to solve it.