Here's a possible spanner in the works for a record-mild January.
It will depend on how much amplitude the MJO carries into phases 6 and 7, as these promote high pressure across the UK in positions that tend to become chilly at the surface - though only with much probability for phase 7, which is currently looking questionable.
If it only holds through phase 6, then high pressure may dominate but from too far south to bring low temperatures to the CET region.
Incidentally, propagation to phase 7 could also set up some interesting stratospheric events... provided enough of the MJO action is in the N. Hemisphere. I'm still haunted by last year's S. Hemisphere-skewed MJO in Jan-Feb and the resulting huge shortfall on cold UK weather (albeit not entirely fruitless).
Originally Posted by: Stormchaser