Early this morning at around 02 UTC the air temperature in Ullapool was a remarkable 18.2°C, that’s according to the Met Office WOW site. I am always wary and skeptical of many of the observations found on the WOW site run by the Met Office. In my opinion there are just a few good well sited and professional AWS mixed in with many poorly sited substandard ones. Here are screenshots of the observations and a graph of the overnight temperatures from the site at Ullapool.
It’s entirely plausible that there was a foehn effect during the night in that part of northwest Scotland, things like that have happened before. Just to the SSW of Ullapool lies An Teallach (3,484 ft) a massive wall of a mountain, which could have forced a pulse of warmer air over it and down the slopes towards Ullapool. A couple of questions occur to me. If this is the case why isn’t the foehn still occurring? Why wasn’t this warm pulse of air tempered by the cold water of Loch Broom by the time it had reached the town? Who knows perhaps the temperature may have been even higher on the other side of the loch.
These are the observations from the SIESAWS on the Bealach Na Ba pass close to the high road to Applecross and around 60 km to the southwest of Ullapool. There certainly was a strong south south westerly blowing at 2,500 feet at the time in the warm sector, with winds meaning 60 knots and gusts as high as 83 knots, there was also an interesting peak in temperature there at 01 UTC to almost 9°C which fits. But could the air have warmed by almost 10°C in it’s descent to sea level? Answers on a postcard please to the usual address.
I completely missed the report of 19.2°C that also occurred at 02 UTC on the WOW website but this time it occurred at Easter Badbea on the south side of Little loch Broom. Easter Badbea is a little further south and west of Ullapool but still has a lot of high ground to the south.
The winds at Easter Badbea were also very gusty at around the time temperatures soared above 18°C. The wind direction was variable and at times was diametrically opposed to the gradient direction. This could be a commonly observed feature of strong SSW winds blowing down from the higher ground to the south with some kind of rotor effect at times.
I’ve also just come across these Met Office observations from Elphin (99153) which lies about 19 km to the NNE of Ullapool. They too show a plume of higher temperatures of 15.6°C at 02 UTC but not just quite as high as the 18.2°C at Ullapool or the 19.2°C at Easter Badbea. Unfortunately I can’t access the 21-09 maximum temperature because these observations are on a need-to-know-basis and I don’t need to know. I was quite skeptical at first, but I now believe we may have witnessed a record December maximum temperature for the UK unofficial as it is!