The mixing issue is just one of many issues it has. Being overly dry and well too far north on placement of the heaviest QPF are also big issues. The NAM is a complete toss, and that’s an understatement. .
Only goes to 90hrs, but aloft would suggest it would end up potential south of 12z. More ridging ahead of the closing off wave, however like the GFS, the northern stream is pressing in more across Canada. .