I think it happens when the servers get full. When I normally ping at 60-70 when servers are full jumps up to 100-130 ping. When there are full players with 600-900 ping playing Drowns the servers.. Cheers!
i was playing on US1 and it was definitely smoother than it has been in quite a while. I don't know if it's coincidence or not, but thanks for the reboot.