Why? The 9'ers have a great defense which is a huge plus in 'those elements'. They can run the ball, another plus. Keapernick can run, yet another plus and, biggest of all, they were a play from winning the SB last year so, motivation will be ZERO concern.
Add to that, the Packers have to play in the same weather. Their Defense is mediocre at best and their offense is a precision outfit that, if anything is going to suffer in the elements, that's it.
To top it all off, the Pack has been squeaking by over mediocre teams for what, 4 weeks now? That all comes to a sad, brutal end today.
49'ers win easy and it won't be close.