That's my setup as well. My UFW looks like:

To                         Action      From
--                         ------      ----
80/tcp                     ALLOW       Anywhere
443/tcp                    ALLOW       Anywhere
xxx/tcp                   ALLOW       Anywhere

I have my DirPort set to 80 and ORPort on 443. The last line is my ssh port (I didn't want to broadcast it).

I also see the same type of blocked incoming packets. It's never been a problem. I think it's just the nature of the stateful firewall. Once connections are closed and no longer in the state table, additional packets are getting denied. That's my lazy/gut explanation, I don't have more time to think about it at the moment, but I don't think it's anything to worry about.