Keep in mind that the MJO, though quite important, can sometimes be overruled by other factors. Whereas outside the COD phase 5 is on average one of the warmer Dec phases for the SE, that is just an average.  Just last year the coldest air of the winter in the SE by far was during the period Dec 23-26, which was during high amplitude phase 5! (see below). The main driver was a very strong -AO teaming up with a moderate +PNA along with a strong -EPO that had just ended. There actually was a