This is what the surface temps look like when the mild airmass is at its greatest NE extent:
(Saturday early morning)

After this point deeper cold returns. Temps near freezing for most eastern parts, 850s are about +2C at this point, so a significant warm nose.
With the deep cold restablishing itself on saturday, the rain snow boundary starts to move back SW:
(Saturday mid morning)

The T850s at the snow/rain boundary here are about +1C, this is the most extreme warm nose effect I think I've seen in the UK since about the end of the 2010 cold spell where we have snow falling in positive uppers. Over the pennines where the blue is, I'd expect a big freezing rain or ice risk.
EDIT: This gets really complicated a few hours later, the uppers cool down alot but the surface warms, seemingly what's going on here is the warm uppers that are now retreating have had time to mix down a little just in time for the deep cold to return. So precip type is going to be all over the place in this scenario.
Edited by user
Wednesday, February 12, 2025 9:47:03 AM
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Reason: Not specified
25/26 (850hpa temp) 11 days snow/sleet falling
18/11 (-4) 19/11 (-6) 20/11 (-6) 01/01 (-7) 04/01 (-10) 10/01 (-7) 11/01 (-3) 30/01 (-1) 13/02 (-6) 15/02 (-4) 18/02 (-6)
24/25 10d
18/11 (-6) 19/11 (-6) 23/11 (-2) 22/12 (-5) 04/01 (-5) 05/01 (0)14/02 (0) 15/02 (0)12/03 (-6) 13/03 (-6)
23/24 8d
29/11 (-6) 30/11 (-6) 02/12 (-5) 03/12 (-5) 04/12 (-3) 16/01 (-3) 18/01 (-8)08/02 (-5)
22/23 7d
18/12 (-1)06/03 (-6) 08/03 (-8) 09/03 (-6) 10/03 (-8) 11/03 (-5) 14/03 (-6)
21/22 12d