I don't think cat 4 would be out of the question... with its forward speed still increasing, it would not take much improvement in the storm itself to bring max winds near cat 4 intensity. I don't know if they plan to have another plane into it or not, though, and that would probably be a tough call based on satellite presentation alone.
their calling it a 3 with FL winds peaking at 136kt is a little inconsistent with the storm being a 3 earlier with the normal reduction suggesting a 2. i guess they think it isn't mixing to the surface for whatever reason. not my area of expertise. -HF