NaNoWriMo Brainstorming...What if...?

It's less than a week to the start of NaNoWriMo. I'm in the process of brainstorming ideas on where and how to start on the first of November. I want to follow the counsel of Stephen King, as he wrote in his book On Writing. The way he writes stories is to create a situation, first. Then place characters in that situation and narrate what happens.

A strong enough situation renders the whole question of plot moot, which is fine by me. The most interesting situations can be usually expressed as a What-if question: What if vampires invaded a small New England Town? (Salem's Lot)... What if a young mother and her son became trapped in their stalled car by a rabid dog? (Cujo)

I'm trying to think of interesting situations in which to eventually put my characters. Any ideas?