Hello! We're expecting an hour of downtime starting approx. 1:30AM PST, i.e. in 3 hours from the time I write this post.
The downtime is to add a new dedicated database server in order to improve site responsiveness, reduce load, and add capacity for other goodies planned down the track.
As usual, only gameside will go down; the forums will stay up, but you will be unable to login. If you are already logged in, you can sometimes remain that way, especially if you navigate only by clicking internal forum links.
Apologies for the inconvenience.