My best Perseid meteor candidate out of 704 photos

I left two cameras out last night. Tonight it's overcast so it looks like my chances of catching a fireball on camera are slim. Here is my best candidate for a meteor from last night's batch. I've had bad luck with mis-identifying satellites and other faint streaky objects, so I'm just calling my finds "meteor candidates" from now on. 

This one has no streak in the frames before or after, and has a characteristic "head" (bottom left) that makes it look convincing to me, but what do I know!

Single frame, ISO 800, 20 sec, f/4.5, 18mm