Taken from NW Peter
ECM ensembles watch
Looking at members with 850Hpa of minus 5 or below for large parts of the UK:
D11 36 yes, 15 no
D13 36 yes, 15 no (though different runs)
D15 36 yes, 15 no (again, some different runs)
Still remarkable consistency for cold for such a long way out
Edit: forgot to mention, probably half of the runs which failed to show minus 5 uppers at the precise time had very cold air very close by, either leaving or about to come in.
Yes, exactly. Without going through the 50 permutations I'd guess that very few will have the high pressure in the same place as the Op.
The polar vortex being split almost into three chunks is also notable.