Both models' 12Z operational runs now bring in warmer air next Saturday.
That's as far as the UKMO run extends, but after a milder weekend the
ECMWF brings the easterly back on Monday and for the rest of its run.
The ECMWF ensemble isn't out yet, but will be interesting.

Before then, Thursday and Friday still look like being very cold, and I
reckon based on the 850mb temperatures that the maxima of 1-3C shown on
the Countryfile forecast for those two days are on the high side. I
reckon that in the eastern half of England temperatures are unlikely to
get above freezing on those two days.
--
John Hall
"The power of accurate observation is commonly called cynicism
by those who have not got it."
George Bernard Shaw