I'll try to kick this off with an image from England in the 1300s:
I'm hoping that's Boreas blowing in some cold winds under a storm cloud in the top right corner.
Indeed! Here was the Dec 26th run of the Euro Weeklies for Jan 15-22:
Right after this, the Euro Weekly runs for Jan 15-22 progressively got much colder. Just one week later (Jan 2), there was this for the same period:
And here’s the final map for the same period, which was released two days ago (Jan 15th):
So, in hindsight, the Weeklies map released on Dec 26th ended up a humongous warm bust and it was issued only 20 days prior to the start of the very c