This is a record-breaking high pressure system

The southern half of the UK is sitting under an intense high pressure system which brought clear skies overnight and an air frost this morning, with a minimum temperature of -1.4C.

Nothing too remarkable there, you might think, but this morning we have recorded an atmospheric pressure of 1044.0 hPa. That’s a new record for this station – the previous high was 1043.9 hPa on 8 February 2012 – and the trend is still upwards (just).

This system won’t hang around for long, unfortunately, so enjoy the cold, fine weather while you can. Quite a contrast to the balmy temperatures we had on Christmas Day!

Warmest Christmas Day

Today has seen an average daytime (0600-1800) temperature of 12.8C, which makes this the warmest Christmas Day since the station was set up back in 2007. Although this time last year was also very mild, it was Boxing Day that produced an exceptional daytime average of 14.2C – Christmas day last year only managed 11.6C.

So – a Merry and Mild Christmas to all our visitors!

Record December warmth!

After a cold start to this month with the temperature never getting above freezing on the 1st, we now have a new record high temperature for December: as I’m typing this at 1345 the thermometer is reading 15.6C and still rising. That beats the record of 15.4C set in last year’s extraordinarily mild December.

Early December’s cold was caused by cold air from the east: today’s warmth comes on a southerly breeze fresh from the Mediterranean, along with some welcome sunshine. This mild airflow is set to stay with us for a few days yet but it will bring some rain as well, so enjoy it while you can.

A cold and murky start to December

Quite a change in the weather for the first day of December. After clear blue skies for the last few days of November, today has seen fog coming inland from the Bristol Channel and stretching across much of Somerset. The sun was could be seen very briefly through the fog during the morning, but apart from that it has been a day of gloom and sub-zero temperatures. In fact today’s daytime (0600-1800) average was the lowest of the year so far at -2.0C, with a maximum of -0.2C at 1252.

It has been an almost completely calm day too (hence the fog), with a maximum gust of just 2kts at lunchtime: most of the day the windspeed has been zero.

November 2016 summary

Early November was cool but generally dry, with high pressure nearby for much of the time to protect us from Atlantic low pressure systems. The result was generally dry weather with some clear skies, but a chilly north-westerly airstream. Fronts from low pressure systems to our north produced a little rain around the 8th, and again on the 12th when a westerly airstream brought temperatures closer to normal.

A couple of deep low pressure systems moved up the English Channel on the 20th and 21st: storm Angus arrived on the 20th and produced wind and rain here, but had more impact on the south-east where winds topped 60mph. A second slow-moving low produced a long spell of rain on the 21st: because this fell on saturated ground there was some local flooding here, and more serious problems further south. The fronts from that system wrapped around the centre of the low, and returned the following day to produce more rain: these two low pressure systems produced 41mm of rain over three days.

High pressure began to build from the north on the 23rd, this time resulting in a cold north-easterly airstream. Cloud kept night-time temperatures well above freezing for a few days, but as the high pressure moved south the skies cleared. There was wall-to-wall sunshine by day making it feel warmer than it was – daytime temperatures peaked at around 6C. The clear skies at night meant sharp frosts, and a new November record low of -5.7C was recorded overnight on the 29th/30th. The last day of November saw barely a breath of wind, and at lunchtime a column of smoke could be seen rising in a perfectly straight line until it hit the tropopause and spread out like an anvil cloud.

November’s average temperature was a 7.0C, a degree or so below normal and our second-coldest November value (November 2010 was colder). Rainfall came to 95.6mm which is a little above average, and the highest wind gust was 32kts on the 17th.