Forget about the seemingly cast iron amber warning for heavy snow that was in force till Saturday because a surprise feed of milder southeasterly winds late yesterday has caused temperatures to rise overnight, and caught out not only the UKMO but old Nostradamus here. It’s meant that much of the precipitation in eastern Scotland has turned to rain below ~400 M amsl. Not that we have had even seen a lot very much rain in the strath either, it looks like we are too well sheltered by the Cairngorms to the southeast for any of that. The thermograph from Aviemore does suggest that there may have even a bit of foehn warming on the leeside of the mountains going on as well. I have no idea why none of the NWP models picked up on this milder air earlier. All in all a bad night for snow lovers in this part of Scotland. Eventually the air will turn colder again as winds back into the east over the weekend, but even that will be a slow business. There’s no doubt we are in for a very cold week and the best prospects for snow now is in the form of snow showers being driven up the Firth in the easterly. Even though we have seen a lot of snow in the last 24 hours across the Grampians I think it quite likely that the amber warning will be cut short and replaced with a yellow warning this morning, but who knows they may try to brazen it out.
I notice the UKMO in their analysis never added an upper warm front ahead of their surface warm front in their analysis like I’ve suggested with the red dashed lines. I have absolutely no idea if such a feature exists, but I’ve done it because the position and orientation of their warm front doesn’t explain the warming we’ve seen much further north.