An evolution that seems plausible based on long range guidance would be:
1. 1-2 strong cutters wave break during the Dec 29-Jan 2 period. This builds the NAO ridging.
2. They being in a cool, but not cold airmass for Jan 3-5.
3. Their remnants park in the 50/50 zone and provide confluence.
4. Another s/w approaches with a good track and acceptable airmass.
5. Profit