By
UK_Palms
I may have to crack out the shorts next week for work. My written rule is that anything over 16C / 61F is typically shorts and t-shirt weather in my line of work. Otherwise I will overheat if I am working in jeans and a hoodie inside the warehouse. Those forecasted nighttime temperatures are ridiculous as well for 51N during the last week of December. I would expect nighttime lows of 13-14C in July, let alone late December. Some model runs are putting the nighttime lows at 15C for Wednesday and Thursday following a high of 18C / 64F on Wednesday!
14C at 850hPa translates to about 17-18C at ground level. It will be interesting to see just how warm it gets, especially if some eastern places also benefit from a Foehn effect too. Potentially 20C / 68F in a few eastern locations, although I find that hard to believe during the last week of December at 51-54N. Probably 18C maximum. If we had a setup like this in July it would bring 35C+ temperatures.
The consistency of the ensemble runs is remarkable! I have never seen a set of ensemble runs so consistent like this. It looks like this warm/mild spell is nailed on now.
Here's the ECMWF for Wednesday, which is supposedly going to be the warmest day, although it could be any of Wednesday, Thursday or Friday in theory.
UKMET pumping higher pressure and warm air up from Africa, although the airflow into western Europe and the UK is coming up from the Canary islands specifically.
The GFS model puts Jan 1st / New Years day as the warmest day potentially...
Here's the ECMWF model for New Years day. Both setups looking very similar. Potentially record breaking in many places on the western half of the continent.
December records, and possibly winter records too, may tumble next week in Spain, UK, France, Netherlands, Germany etc. Watch this space. Daytime maxima and nighttime minima both at threat.