As long as it faces out of the wind I would say yes. It also depends on where you are located. It it gets super nasty out you can always lower ( or add) that tarp in picture #2 a bit lower to create a 4th side.
We have about 3 ft of snow in the winter and stay below zero for days at a time and our sheep like to lay out in the snow. We do have barn and straw shelter they have the option of using, but 90% of the time they prefer just laying out in the open.
This is just for the adults. If you might need to expand to guarantee that lambs would have enough room