[sourdough]

I would be worried about it. That's an awfully big crack that goes ??? once under the surface. Also, looks like a healthy crack developing/developed going toward the front right over the edge where the roofing material attaches. I would dare say that's been going on for quite some time. Just looking I would encourage you to go over the entire roof and check the sealant. If the other is as aged and cracked as that it is there's no telling what's going on.