Take a look at
http://www.panoramio.com/photos/original/558983.jpgfrom the new topic Raddison nest site. I'm guessing they are on the roof of that little projection with a window on the north and east side of the building.
I was in that window taking pictures last summer, and there were no water leaks on the ceiling. On top of that, I watched the falcon feather circling the drain for a while. The drain is working. All this is cold comfort (pun noticed but unavoidable) but I am less worried about the chicks drowning.
From the posts on the new topic Radisson Nest Site, the flickers of motion in my upper right corner of my picture are pedestrians.
Also I would guess the parents chose this side because most storms come from the west, and they wanted to get out of the weather this year. I have this hunch next year Princess will definitely be in the box. That huddle of feathers in the corner doesn't look like a happy camper.
I wish I were guessing and hoping less and knowing more. Hey, why be a Piker? I wish it was sunny, at least until the chicks can self thermo regulate.