Wednesday 3rd December
We are now in an unsettled Atlantic pattern of weather, Tuesday was just such an example. After a dry and sunny morning, showers occurred early afternoon and again in the early evening that amounted to 3.4mm of precipitation. The mild, moist air stream lifted the thermometer to a peak of 10.6C at 12.56 before the cloud built up and shower activity arrived. This high was 3.1C above average. The cloud cleared after 18.30 that saw the temperature slowly subsiding, reaching a low of -0.8C at 06.29, being 2.7C below average. The low temperature resulted in an air frost but also produced fog around dawn as the moisture in the atmosphere condensed when it could hold no more moisture as the temperature dropped.There was thick fog in both the River Og valley and River Kennet Valley.
Wednesday after dawn revealed variable fog that by 08.00 had begun to disperse, by 08.30 just misty conditions, however, the thermometer continued to fall reading -1.0C at 08.21.
A powerful jet stream will be in position all week that will drive successive low pressure systems across the UK resulting in variable weather, sunshine and showers. The warm air flow, mainly from a southwesterly quadrant, will maintain above average maxima for several days whilst, other than early Friday, will see minima a few degrees above freezing.
There is the likelihood of a deep depression arriving on Friday, centred in the eastern Atlantic, that could produce substantial rainfall.