ECM 00z ensemble for London
Finally the GFS op has deciphered the pattern for this week with the cold air becoming established until late Friday - or Saturday per ECM.
The warm up shown by ECM (for the second successive run) is notable: a high of 3c on Friday to a high of 13c 24 hours later. The op was amongst the mildest options, but double digits looks quite possible at this point.
Beyond that nothing exceptionally cold but the milder options diminish somewhat. At this stage you'd favour a Christmas with normal to slight cool conditions, with highs of 5-8c and lows of 3-5c.
Location: South Cambridgeshire
130 metres ASL
52.0N 0.1E