Under the continuing fog with just a brief break of sunshine after midday on Thursday, the thermometer struggled to reach 4.5C, being 3.6C below average. After a month when almost all maxima were above average it has come as a shock to find the cold has arrived with the forecast of colder next week.
The breeze from the northeast was very light with a maximum movement of just 7mph also many hours of total calm.
Overnight the temperature stayed above freezing, just, with a low of 0.4C being 2C below the average.
Friday dawned dull and gloomy with persistent fog again but slightly less thick limiting visibility to 400m.
November 2022 Review
November began with a bang as Storm Claudio approached our shores bringing wind gusts of 34mph on the 1st and 44mph on the 2nd. It was named by the French Metrological Office as the main impact was felt by northwest France. The south and southwest wind also brought much rainfall with 6.3mm on the 1st and a substantial 19.5mm on the 2nd being the wettest day since 21st October (31.1mm).
Storm Martin closed in on the 5th with modest rainfall totals on a warm south-westerly breeze.
Another deep depression developed in the eastern Atlantic that impacted our country again on the 7th with more rain and strong winds gusting to 40mph on the 8th.
Throughout this period the warm air, brought on the south to southwest wind from far south in the region of the Azores and North Africa, meant both maxima and minima were well above average, much welcomed in minimising heating costs. The maximum of 14.4C on both the 7th and 8th were 4.3C above the 38-year average whereas the very mild night of the 7th/8th gave a minimum of 11.6C, which was a significant 7.9C above the long-term average.
That was not the end of the warm period as on the 12th the thermometer soared to 17.5C. That was a record-breaking temperature being a significant 7.5C above the 38-year record for this station and overtook the record set on 4th November 2010 with 16.7C.
After such exceptional warmth it is pertinent at this point to note the report published on Sunday 15th November by Copernicus entitled – Europe Poised for a Warmer-than-Normal Winter.
Europeans have a greater probability of experiencing temperatures significantly higher than normal this winter, according to the European Union’s Copernicus Climate Change Service. The Copernicus model combines data from scientists in the UK, France, Germany, Italy and the US. The EU program uses billions of measurements from satellites, ships, aircraft and weather stations around the world for its monthly and seasonal forecasts and concluded that 2019 was the continent’s hottest year on record.
Scientists at Copernicus reported in their most-closely-watched seasonal forecast that coastal regions along the Baltic, Mediterranean and North Sea are almost certain to see temperatures exceeding historical averages. The degree of certainty of warmer weather rose over the last month.
There is a 50% to 60% probability that temperatures will be significantly above historic norms across much of the UK, central and southern Europe.
The warm air that streamed up from far south during the previous week was due to a strong jet stream flowing north to the west of UK. From the 15th, it repositioned to the south feeding in a succession of depressions. Rain band after rain band produced significant rainfall, except the 17th and 18th. By the 19th the monthly rainfall total exceeded the 38-year average. During the course of four days the daily total was substantial with 11.4mm, 18.7mm,11.0mm and 10.5mmm recorded for the 14th, 15th, 16th and 21st respectively. It was at this point in the month that water began to flow above ground at Winterborne Monkton where the River Kennet rises. Perhaps that is why Thames Water announced on the 22nd that the hosepipe ban was lifted due to water beginning to fill the aquifers.
Incidentally, my rain readings are taken from the standard Meteorological Office 5inch copper rain gauge. On the very rare occasion I am not at home to take the reading at 08.00, the automatic rain gauge is used as a backup but can on occasion give a slightly less accurate reading due to air currents affecting the precipitation captured as the gauge is one metre above ground level. However, on the 22nd there was an obvious problem with a gross under reading from the automatic gauge. On inspection I discovered that a bird had used the gauge as a brief perch and had left a deposit in the receiving cone thus blocking the progress of the captured rainfall through to the tipping mechanism below, but it was very quickly cleared and reinstated. The advantage of these gauges is in giving real time readouts of rainfall, which can be so useful.
Key devices for recording weather used throughout the world owe their designs to the efforts more than 150 years ago of a Hampshire clergyman. When meteorology was becoming a science, the Rev. Charles Higman Griffith, rector of Stratfield Turgis, studied 42 different designs of rain gauges and 10 different thermometer screens in his garden. Amassing huge amounts of data, he showed that rainfall was most reliably recorded with the ‘Snowdon five-inch copper rain-gauge’, named after the mountain, which became the standard device for recording rainfall.
A gentleman named Symons later initiated moves to record rainfall more accurately. In the early years of the ‘meteorological department’ of the Board of Trade, founded in 1854, he had joined Vice-Admiral Robert Fitzroy – famed as the captain of HMS Beagle, with Darwin aboard. Symons wanted to respond to national fears of water shortages. Years of drought in the 1850s had sparked government concerns that there would be insufficient water to supply the burgeoning towns and cities of industrial England.
Symons therefore left the fledging Met Office and set up the British Rainfall Organisation (BRO). In the 1860s, in order to decide how best to record weather, he recruited some 150 recorders throughout the country. The recorders’ task was at exactly 9 am every day to measure the volume of rain that had fallen in the previous 24 hours. For the trials of screens for measuring air temperature the requirements were more exacting – it had to be recorded three times a day, at exactly 9 am, 3 pm and 9 pm, plus the maximum and minimum values of the day.
In 1874, largely due to Griffith’s work, the Board of Trade adopted the Stevenson screen as standard and a year later the British Rainfall Organisation did the same for the Snowdon rain gauge.
Mention must be made that several hours of glorious sunshine were enjoyed on the 25th.
A distinct change in our weather began to develop from the 28th as the succession of depressions, accompanied by rain bands, arrived from the Atlantic and were replaced by a very large area of high pressure to the east. The wind began to veer into the north and southeast on the 29th and then fall light. A maximum movement of air on both days was just 7mph, couldn’t be called a gust, with many hours of calm. This almost static air mass, combined with the coldest night since early October allowed fog to form in the early hours of the 29th and 30th limiting visibility to 200m.
No air frost was recorded in November, not a record as no air frost occurred in November of 1994 and 2009 but there were a few air frosts in the preceding October of each of those years, so it has been an exceptional month.
The month ended with a cold spell as an intense area of high pressure over Russia began to influence of weather with an air flow from an easterly quadrant. The cooler air meant that for the last three days both maxima and minima were below average, quite a change from the month in general.
November was another month in 2022 that produced an above average mean being a significant 2.2C above my 38-year average. In fact, every month in 2022 gave us an above average temperature excepting January. The mean temperature for November has shown a gentle upward trend since 1993, now being 0.6C above the average before that year.
There has been a gentle increase in the trend for wetter Novembers with on average a rise of two days when the rainfall was equal to or above 1mm, as defined by the Metrological Office.
The significant rainfall in November amounted to 134.1mm being 149% of the long-term average or 44.3mm above. Although it was a very wet month the total rainfall for the period January to November is still 173mm below the 38-year average.
The succession of depressions that affected our weather can be seen by the barometric pressure being 4.5mb below the long-term average.
Autumn 2022
The mean temperature for Autumn 2022 was 1.4C above the long-term average and has shown a slowly rising trend since 1996, now 0.5C above the previous mean temperature.
The total rainfall for the three months was 302mm, an increase of 60mm over the long-term average.