The ceiling just caved in.
I have some good news and some bad news...the good news is that the ceiling will be easy to fix but the bad news is that you have very serious roof problems that need immediate attention. The water getting into your attic will do serious long term damage if left as is. That is a huge piece of asphalt that the wind blew off. Your roof is not shingled, it's called "roll roofing". Nailing the broken piece back on wouldn't help much. You need a tarp held down by furring strips (1" x 2" strips of wood". The tarp should stretch over the peak of the roof at least a foot so the water cannot get under it. But even that is a short term solution. I'd be calling a roofer and when you tell him you see daylight through the hole they should treat you as an emergency.
Let us know if you need more help. BTW, where are you located?
Best of luck,