Cold by day and night also November review

Sunday was the first day of Meteorological winter and it was cold. With a modest breeze from the north east and little sunshine, just 1.7 hours, the thermometer struggled to reach 5.5C, which was 2.5C below average.

A clear sky overnight saw the thermometer plunge to a minimum of -1.7C being 3.9C below average.

The barometric pressure has continued to rise with a very high reading of 1032.0mb at 08.00 on Monday morning as a ridge built over the country.

Monday morning was bright and crisp with sunshine as the sun rose above the horizon. The temperature at 08.00 was -1.4C

November 2019 review

November began much as October with an ex hurricane affecting our weather. Pablo was the first such storm to form so close to the UK, just west of Iberia. It brought mild weather with temperatures from the 1st to the 5th a degree or so above average, a peak of 14.5C was recorded on the 1st being 3.4C above the 35-year average.

The warm air was maintained during the nights also but storms bring high winds and we suffered from gusts of 24mph and 38 mph on the 1st and 2nd. Being many miles inland means that winds are moderated by the time they reach Wiltshire as at that time winds gusting to 83mph were recorded in Plymouth and 109 mph on the Isle of Wight.

You might have thought your wall barometer had broken during this period as it dropped so far. In fact the lowest barometric pressure was observed on the 2nd with a reading of 976.1mb making it the lowest pressure since December 10th 2017. This was not a record as a reading of 967mb was taken in November 2010.

The first half of the month was a very wet period with just two dry days by the time we reached the 15th. Significant falls were recorded on the 6th, 9th and 13th with 15.9mm, 21.8mm and 10.2mm respectively.

Once again we have been very fortunate in that the torrential downpours were away from this part of the country. Whilst we had very wet days the Peak District for example had 112mm in 24 hours whilst Sheffield was drenched with 85mm, almost a month’s worth of rainfall in a day.

Following this period the weather took a turn for the worse with both maxima and minima below average. There were 19 consecutive days with below average daytime peaks, with just 4.6C on the 30th being the coldest in November, a drop of 5.5C on the average.

The jet stream subtly changed direction mid-month allowing the barometric pressure to rise to its highest reading all month at that time of 1018.1mb on the 18th. This gave a slightly drier period with five dry days between 16th and 20th, just 0.3mm on the 17th.

There were many cool nights with a sharp frost on the morning of the 8th when the thermometer fell away to -2.2C.

The advancing ex-tropical Storm Sebastian made itself felt on the 26th with a temporary milder spell as the thermometer edged back above average due to the weather fronts that also brought considerable rainfall with tropical air crossing the country.

Due to the jet steam producing a conveyer belt of numerous depressions that crossed the country in November it was not surprising to find that the rainfall was above average and temperatures depressed.

The rainfall for the month amounted to 116.7mm, which was 24.6mm above the 35-year average. There have been 11 wetter Novembers with the extremes being 27.8mm in 1990 and 203.5mm in 2002. The wettest day occurred on the 9th November with a substantial fall of 21.8mm.

The trend for the number of wet days in the month, described as equal to or above 1mm, has been slowly rising since my records began in 1984 when there were on average 12 wet days, which has risen to an average of 14 in recent years with 2019 producing 16 wet days.

Taking a wider view, looking at the 11 months from January to November in 2019, I find that 865mm of precipitation has fallen whereas the average over the past 35 years is 756mm.

Turning to temperatures, the many days of gloomy, wet weather meant a cool month. The mean temperature was 1C below the 35-year average with only 10 cooler months recorded since 1984. The warmest day occurred in the 1st with 14.5C.

There were 7 days when an air frost occurred dropping to -2.5C in the early hours of the 19th. Analysing the diurnal data, that is the range of temperatures between the highest and lowest on any one day, I find that for the month of November the range has slowly increased from 11 days in the 1980s to an average of 14 in recent years.

So in summary a cool, wet and predominately gloomy month with no UV registered during 5 days and 10 when the sunshine recorder was not triggered.

Autumn 2019

Even with short memories we recall it has been a wet autumn. The facts show that 380.7mm of precipitation was recorded making it the 4th wettest autumn since my records began in 1984. The mean temperature for the three months was 0.5C below the average making it the coolest since 2012.