Exceptionally mild November weather by Alex Deakin
Over the next few days temperatures are set to rise across many parts of the UK with temperatures expected to reach the mid teens Celsius (low 60s F).
The mild spell is attributed to an area of high pressure which is moving up from the Azores and is expected to settle over the Bay of Biscay. Warm air along the western side of the high pressure will spread over the UK through today and overnight.
The average temperatures for mid November in the UK range from 9 to 11C (48 – 52F). Temperatures over the next few days will be around 5 Degrees Celsius above this average. The highest recorded November temperature in the UK was 21.7C (72F) at Prestatyn, North Wales in 1946.
This record high temperature was due to the ‘Föhn effect’ phenomenon. The name is derived from a German word given to a wind local to the Alps, which is most noticeable in late winter and spring. The phenomenon also occurs in the British Isles when warm, moist air from the southwest rises up one side of a mountain range. As the air lifts it slowly cools, and moisture condenses over the mountains. Dry air changes temperature much more quickly than moist air, so as the air in the Föhn descends down the leeward side of the mountains, it warms more rapidly than it cooled on the way up. The air therefore reaches a higher temperature at the end of its descent than before it started rising.
Areas most favourable to the Föhn effect in the UK are Northeast Wales and eastern Scotland. Places that could benefit from this phenomenon on Friday include Leeds, to the east of the Pennines, and Aberdeen, to the east of the Grampians.
With high pressure set to remain across the Bay of Biscay, the UK is likely to see above average temperatures right up until this coming weekend.
