Yes this may surprise some people but I am expecting a big snow event on the 18th, probably mostly for Scotland and the far N England but details are not figured out yet.
This is one of my favourite scenarios because it always takes people by suprise. Behold the slack low snow situ! Basically take a completely benign synoptic pattern (cold established not necessary!) and bring in a young, active, wavelike low into it. Result: Rain->snow even to lower levels.
Established cold air is not necessary because the cold air is generated in situ by evaporational cooling. As such almost 0 windspeed is
essential, you also need rather heavy precipatation and lowish humidity. These conditions are satisfied with a very young secondary low with almost no V bend. This is a low forming in a region of significant baroclinicy (temp gradient) but has not yet developed its own closed circulation.
Now these lows have strong westerly winds on their southern flank, so no chance of snow there, but within a tiny distance (maybe 50 miles) you can go from strong westerlies to almost nothing; and that's where you get the snow. And yes the snow will likely settle even if it takes hours for the rain->snow transition to occur.
Twitter: @QuantumOverlord (general), @MedicaneWatch (medicane/TC stuff)
2023/2024 Snow days (approx 850hpa temp):
29/11 (-6), 30/11 (-6), 02/12 (-5), 03/12 (-5), 04/12 (-3), 16/01 (-3), 18/01 (-8), 08/02 (-5)
Total: 8 days with snow/sleet falling.
2022/2023 Snow days (approx 850hpa temp):
18/12 (-1), 06/03 (-6), 08/03 (-8), 09/03 (-6), 10/03 (-8), 11/03 (-5), 14/03 (-6)
Total: 7 days with snow/sleet falling.
2021/2022 Snow days (approx 850hpa temp):
26/11 (-5), 27/11 (-7), 28/11 (-6), 02/12 (-6), 06/01 (-5), 07/01 (-6), 06/02 (-5), 19/02 (-5), 24/02 (-7), 30/03 (-7), 31/03 (-8), 01/04 (-8)
Total: 12 days with snow/sleet falling.