How to fix this?

I moved the MH from her storage shed out to the side yard yesterday in prep for upcoming travels. It wasn't until I'd put out the awning however, that I noticed this awful crack running from the corner of the bedroom window, diagonally up towards the roof! I'm not worried about stopping the crack, as it's already gone as far as it can go... but I really would love to fix it so that the rain doesn't run inside the open gap! There's doesn't seem to be any delamination anywhere other than the area right around the crack itself.

Can I fix this? How/what should I use?

Here are pictures of the crack.
http://1drv.ms/1HbSEyj