Saturday 7th November
Friday produced bright intervals in mid-morning, and again briefly in the afternoon, that saw the thermometer rise to a peak of 10.5C at 12.55, being 0.2C above average. The minimal air movement from the east meant it felt less cold than previous days. The low of 4.8C just after midnight at 00.36 was also above average at +0.9C.
The fog had formed overnight that limited visibility to around 100m at 08.00, in fact the mist began to form Friday evening that intensified overnight under calm conditions. The anemometer was stationary at 08.00 and had been almost all night, there was a flicker of movement just before 07.00, before it fell still again. The fog will be slow to lift and clear today.
The air stream will make a significant change in direct to come from the southwest tonight and Sunday before reverting to an easterly direction for much of next week. This could produce a brighter day on Sunday.
The recent high pressure will continue to be the dominant feature over the weekend with calm conditions and fog likely to form overnight again early Sunday. A depression has been edging closer in from the Atlantic that has been blocked by the high pressure to the east. It will seek to push weather fronts across the UK from Monday that could produce showery activity but the high pressure will minimise the forward movement of the depression. The light, easterly breeze is likely to continue all week.
For this weekend and into next week I will attach images from the Royal British Legion National Remembrance Gardens.
Part 2 of the Met Office press release on the stratospheric polar vortex (SPV) that has been in the news recently.
Why forecasters monitor the SPV
Monitoring the SPV is an important part of understanding medium-range and extended-range weather risks during winter. Its behaviour can provide useful context on whether the atmosphere is more likely to favour mobile, Atlantic-driven conditions or a greater chance of blocked patterns and colder outbreaks. It is one factor among several, including sea surface temperatures, tropical weather patterns, existing pressure systems and short-term developments in the jet stream.
For the UK, the SPV is therefore best thought of as a background driver that can tilt the odds towards certain weather patterns, rather than a switch that turns cold weather on or off. A strong SPV often supports mild, wet and windy winter weather from the Atlantic, while a weakened or disrupted SPV can increase the chance of colder, more blocked patterns.
Sudden stratospheric warming is one of the clearest examples of this connection and it most often leads to cold dry conditions but this depends on how the whole atmosphere responds in the days and weeks that follow.