Still disturbed weather on Sunday

Sunday had a wet start adding another 12.1mm to the total, but by mid-morning the rain had ceased and the sun appeared. However, the southerly wind was very strong with a peak gust of 35mph, the strongest all month. In fact it was the strongest gust since 21st May when 42mph was recorded.

The maximum of 13.9C was just below average although the minimum of 7.4C was significantly above the early November average (+3.6C).

Monday started with variable cloud and much welcome sunshine shortly after dawn.

October 2021 review
The month started off well with 6 hours of sunshine and a temperature above average but the 2nd saw rain fall for 11 hours producing 23.1mm of precipitation making it the wettest day since October 3rd 2020.

The 4th produced another 10.7mm of precipitation that brought the monthly total to 39.2mm, almost half the average for October in the first 4 days.

However, Tropical Maritime air arrived on the 6th and by the 7th with dry conditions and a maximum of 20.3C. This high was some 5.8C above the 37-year average and no rain.

There was a very pleasant dry week from the 9th to the 15th with temperatures above average and several days with very warm sunshine as a ridge of high pressure settled over the UK.

An exceptional twenty-four hours occurred on the 20th. The tropical air was still in place for the first part of Wednesday the 20th with the thermometer reaching 16.9C being 2.2C above average. However, as storm Aurore, named by Meteo-France, moved eastwards along the English Channel and Southern England, a dramatic change occurred in our weather.

Just after 1600 the wind began to veer from the southwest to southeast then northeast mid-evening before coming from the north at midnight and northwest at 0100 on Thursday. This swift change in wind direction was due to the changing position of the depression as it moved eastwards.

Rain from the depression was noted just before 1950 and continued for four hours, often heavy, producing another 20.3mm of rainfall that brought the monthly total to 89.1mm being 4mm above the 37-year average. The average number of daily rainfall totals exceeding 20mm is 2.6 for the year but it has occurred three times in October and once in September. The record was 6 in 2014.

The temperature after 0300 began to drop, due to the change in wind direction, and fell to 7.3C at 0800 on Thursday. The strength of the wind from this direction and fall in temperature meant wind-chill occurred so that 7.3C felt more like 6.0C at that time.

The wind from the northwest is a drier air current that saw the humidity drop to 76% at 0800 on Thursday, not seen that low at that time of day since 20th July.

The last week in October brought disturbed weather driven on daily by south-westerly winds due to passing depressions. The temperatures fell away by day followed by mild by nights with frequent showers, often heavy. The strongest gust of the month was recorded on the 31st with a peak gust of 35mph.

The average yearly occurrence of a daily rainfall in excess of 20mm is 6 over the last 37 years so it was quite exceptional to have three days in October when that occurred, namely on the 2nd, 19th and 20th with 23.1mm, 23.6mm and 20.4mm respectively.

The rainfall total for October was 135.0mm being 151% of the 37-year average or +45.4mm. The extremes for this month were recorded in October 2020 with 191.0mm and 2017 with 31.3mm. Once again we are fortunate in Marlborough that we have not been inundated with a deluge such as hit Cumbria on the 28th when 370mm was recorded in 41 hours.

The average temperature for October was 12.12C being 1.4C above the 37-year average with the average maximum +1.35C and average minimum + 1.4C – most unusual to have those statistics so close numerically.

We don’t usually associate tornadoes with the UK but England is the tornado capitol of the world, the latest having occurred in Widnes on October 20th.

The US suffers both a higher frequency, about 1200 a year, and those that land are far more deadly.

However, England is home to the highest number of tornadoes by total area. The Guinness Book of Records states that the average is 2.2 tornados per 10,000 square kilometres per annum over the period 1980 – 2019.

In 2015 the University of Newcastle conducted research that produced a map of the areas in the UK most likely to be hit by a tornado. The top spot for UK tornadoes is in the Home Counties between London and Reading and in second place is north from Bristol through Nottingham to Manchester.

The Birmingham tornado in 2005 was the strongest recorded in the past 30 years with a total damage cost of £40 million.