Ohio will not be affected by Sandy, Phillie may be screwed up enough that Western Penn. will carry the state for Mitt. In the same way, rain/damage in Northern VA, the DC suburbs, may suppress the Obama vote. The entire path of the storm is in Obama’s heartland. We'd written the whole thing off, except maybe NH, so it cannot hurt—possibly help.
Hope you're right about PA. Unfortunately, there are still quite a few idiots in the big cities who will still vote for Obama. In Pittsburgh, for example, there was a pro-Obama event featuring Bruce Springsteen. Looked like a bunch of union types in attendance, and some of the attendees were interviewed by the local media. It was sickening. I hope, however, that these are a noisy minority and that most will have seen the light and won't vote to re-elect Obama. It's just not easy to predict.
One factor which might help Romney is that unlike in 2008, the Obama campaign isn't actively arranging transportation for voters here. I'm sure there will be a few buses organized by unions, but it won't be on the same scale as in 2008. Particularly if the weather is bad on Election Day, I doubt that many Obama supporters will make the effort to secure their own transportation to the polls. The entitlement mentality is still prevalent here.