I've been thinking about this too, as living in Western Washington we average 226 cloudy/rainy days annually - and I am not willing to schedule my smoking around the rain.
Here is what I'm thinking. Take a cheap Tupperware container, and then drill a bunch of holes in the bottom and sides of it for ventilation, leaving the top intact as a rain shelter. Use a couple screws from the inside into wooden dowel hunks on the outside to build stand offs so the container doesn't heat soak too much from the SI cabinet temperatures. Then also add a couple stand offs to the bottom of the Auber so that while sitting in the container if any water rolls in from the side holes it'll just roll under the Auber and out the bottom holes.
I know there has to be a cleaner solution for this, but building it sounds like a good way to kill some time and a couple beers, plus it really can't hurt.
Thoughts?