Job? Bad timing?
Alas, it appears the opening is an immediate one. I would not feel right just quitting my current teaching position, even if that postition is uncertain for next year - and there's a good chance I will not learn if I will still have that job until May or even June.
I will apply for the Catholic school position, but with the understanding that I could not start until the fall. And I may still have a job at my current school as it is. We'll see.
[LATER: Called the school. The job has likely been filled. Well, that resolves one potential ethical dilemma!]