Sunday was the first day when the very cold air began to give way to slightly milder air arriving from the west. As a consequence the temperature rose to a high of 4.8C at 14.45, the highest since the 6th, however, this was still 2.3C below my long-term average. It was a dry day under the influence of the high pressure, centred overhead, but thick cloud meant no UV light triggered the UV sensor. Overnight the thermometer slowly fell away to reach a minimum of 0.9C at 02.44 before rising slightly to reach 1.7C at 08.00 on Monday.
Monday after dawn revealed a sky with much less cloud, which was higher and thinner, that should result in weak sunshine as the day progresses. The wind direction, such as it is, has veered a few degrees from south yesterday into the south-southwest.
I mentioned yesterday that the centre of the high pressure was migrating south to be in a position over Southern England for much of the day. The maximum barometric pressure of 1041.6mb was logged at 20.56 Sunday evening, the highest pressure since 5th February 2023 when a reading of 1048.1mb was recorded. The intense high pressure has brought us the very calm conditions for the past few days as there is little pressure gradient to originate much air movement. The maximum air movement on Sunday was one incidence of just 5mph and 8mph overnight, although for many hours the anemometer was virtually still.
The pool of cool air trapped under the high pressure is slowly giving way to warmer air inching in from the west but it will take a another day before temperatures return to near normal for mid-January.
