We can see it from inside, so I checked every five minutes, shining a flashlight through the window glass after the sun went down, to see when it left its roost. The owl woke up around 5:15, spent a few minutes stretching and blinking, and left its branch at about 5:40. By 6:10, it had hit the mist net, and we were admiring it inside the banding lab!
I don’t think I’ve ever touched a fluffier ball of feathers. Partly by shining a blacklight on its feathers (new feathers glow a bright pink under UV), determined that it was a hatch-year bird; just a few months ago, this owl was just an egg in a tree cavity up north. It seems to have settled in now, and might stick around the whole winter. This morning it was back asleep outside our window, as usual.