Author: Eric Gilbert

Saturday was another gloomy, drizzly day with thick cloud ahead of Storm Bella. During the evening the wind began to pick up, but fortunately not as strong as the warnings given. A peak gust of 38mph was logged at 01.29 in the early hours of Sunday. The strong winds began t abate after 02.00.

The southerly air stream allowed the thermometer to recover from the cold northerlies of previous days and reach a maximum 9.4C being 1.4C above average. As the rain band eased away Sunday morning the temperature dropped away to read 5.0C at 08.00

The rain began in earnest just before midnight and brought us the wettest twenty-four hours since the 14th November with 17.7mm. This brought the monthly total to 106.2mm, which is 14mm above the 36-year average.

Sunday morning saw the showery back end of the main rain band with broken sky and occasional showers. The wind has now backed into the west and is much calmer.

The centre of Storm Bella will migrate down across the country in the next twenty-four hours with extremely low pressure centred over southern England on Monday. The barometric pressure has dropped 45mb since 08.00 on Saturday and is forecast to fall another 10mb by Monday morning. The wind direction with change considerably during this period but be much lighter in strength.

The ridge of very high pressure brought us a sunny and fine, if chilly, Christmas Day. The northerly wind for much of the day was much lighter than the previous day with a maximum gust of 13mph. However, the very cold night meant the thermometer struggled to reach 3.3C during daylight hours being 4.7C below average, which meant it was the coldest Christmas Day since December 2010 when the thermometer only reached a chilly -0.1C.

During the late evening, the thermometer having fallen to a minimum of -0.6C at 19.47, saw it reverse the trend and begin to recover as the wind had slowly backed into the west.

Boxing Day arrived dull and gloomy with thick cloud from the approaching Storm Bella. As a result the thermometer at 08.00 read 4.4C and the air mass then coming from a southwesterly direction.

The barometric pressure has been falling for the past twenty-four hours having already dropped 11mb with a current reading of 1022mb. This is the result of approaching Storm Bella that in the North Atlantic has two centres of exceptionally low pressure close together with readings of 955mb and 965mb. Warnings have been given of exceptionally strong winds, up to 50mph, will arrive in this area around midnight.

A transient ridge of high pressure brought very different weather on Thursday with blue skies, four hours of sunshine and the first dry day since the 9th. However, the very brisk wind from the north meant a cold day with the thermometer struggling to reach a maximum of 4.7C at 12.47, which was 3.3C below average and the first below average maximum since the 5th. There was also significant wind chill that outside it felt at least 2C colder than that registering on the thermometer.

Overnight the thermometer fell steadily to reach a minimum of -1.2C at 06.47 being 3.6C below the 36-year average.

The cold air from the north meant it was the coldest Christmas Eve day since 2010 when the thermometer that year refused to move above freezing with a maximum of -0.1C. The cold northerly airstream persisted this past night that meant it was the coldest night since Christmas Eve of 2010 but then the frost was severe as the thermometer dropped to -6.8C.

Christmas Day in 2020 arrived with blue sky and the promise of more sunshine thanks to the high pressure that is at its highest all month with a current reading at 08.00 of 1033.6mb. The thermometer at that time registered -0.6C but wind chill meant it felt more like -2.9C. There was a little whiteness however that was not snow on Christmas Day but frost!

Wednesday arrived with the mild air still in evidence in the morning producing a maximum of 11.7C at 11.14, which was 3.7C above the 36-year average. However, from that time the thermometer edged downwards as the wind slowly began to change direction into the southeast and east but an abrupt change, logged at 21.00, saw the wind back into the north. The wind then gained in strength resulting in windchill that meant it felt at least 2C colder with a maximum gist of 30mph. The thermometer then fell more rapidly producing a minimum of 2.0C at 07.56 on Friday as the warm, moist air was replaced by drier and colder air.

Rain fell on several occasions but quite heavy for a time at 20.35 producing another 8.6mm of rainfall, which took the monthly total to 88.5mm, just 3.3mm below the 36-year average. Fortunately we were just to the south of the intense rain band that slowly circuited to the north and west of this area.

What a welcome sight at dawn to see blue sky and just a small band of cloud on the eastern horizon. The wind from the north was still brisk, gusting to 15mph, that meant the thermometer reading of 2.0C at 08.00 felt more like -0.3C due to wind chill. The drier and colder air is now firmly in control for the next day or two.

Tuesday brought another gloomy day with rain and drizzle. The cloud base dropped in the afternoon that limited visibility to 1,200m at times with fog draping the tops of the Marlborough Downs. The wind from a southerly direction was variable later in the day then coming from the east but very light with a maximum gust of just 11mph.

The thermometer was steady at around 8.3C for much of the day but late afternoon and evening rose to peak at 11.0C, which was 3C above average. Likewise, the minimum of 8.3C logged at 16.45 on Tuesday was 6 above average.

Another 2.5mm of rain was added to the monthly total that now stands at 79.9mm being 11.9mm below the 36-year average. Including Wednesday, we will have endured two weeks of consecutive wet days. Tomorrow should be different.

Wednesday brought the darkest start to a day this month with the cloud base very low, again draping the Marlborough Downs, and rain returning at 05.10 and more persistently at 07.40.