In a pinch, Henry's makes a wet roof patch. I have used it and it works. It cracks after about 2 years, so its fine if you are just extending the life of the roof through winter. A word of caution: this stuff is like the blob. It gets on everything and stays there, I'm pretty sure it has a mind of its own. DON'T wear your new jeans or shirt; and warn the cat not to walk on a treated spot. There will be a little oil slick in wet weather, but it should do the job.