Here it is:
The ridge line of the upper roof and ridge line of the lower roof are perpendicular.
Problem 1: The fascia of the upper roof runs perpendicular to and intersects the ridge line of the lower roof. Basically, a peak is intersecting a level surface. I have some minor leaking there, I believe.
Problem 2: the lower roof's ridge line runs into the upper roof's eaves. So, the builder cut the last two rows of rafters of the lower roof before they peaked, so that they fit within the eaves of the upper roof.
Essentially, if you removed the soffits of the upper roof, you could crawl down into the lower roof's attic space. And, you can get your fingers between the soffit of the upper roof and the decking of the lower roof, so that someone looking up into the attic of the lower roof, could see your fingers.
I think my water problem is not from rain, because the rain runs away from this part of the problem. I think snow is blowing up through the soffits of the upper roof and settling inside the attic of the lower roof.
Solutions?