Saturday 31st January
There was a very welcome sunny and dry morning on Friday with a cool breeze from the south east. However, under the sunshine before the cloud began to build again just after midday, the thermometer reached a peak of 10.3C at 12.43, being 3.2C above average. The first spots of rain from the advancing weather front were observed at 15.30, the rain ceasing just before 18.00. The daily rainfall amounted to 4.6mm that took the monthly total to 160.6mm. This total was 169% of my 42-year record making it the second wettest January after the deluge in 2014.
As the cloud began to thin the temperature been to very slow drop under clearing skies resulting in a minimum of 4.1C at 07.32 early Saturday.
It was a treat to see the last of the cloud on the eastern horizon and blue skies beginning to be more prevalent after first light on Saturday. However, we are still experiencing unsettled weather so the day ahead will have mixed fortunes, sunshine and possible light showers. The recent depression relocated a little further north over the past twenty-four hours, which resulted in the wind backing into the south late yesterday, hence the slightly warmer conditions.
The wind continues from the south again today and tomorrow, so a couple of slightly warmer days ahead. The high pressure has become resident over Scandinavia recently and is forecast to settle there into next week. This will result in the anticyclone continuing to act as a ‘blocking high’ deflecting advancing depression towards the north after they have arrived over the UK.
What causes the jet steam?
Earth is split into two hemispheres, and air is constantly moving around to spread heat and energy from the equator to the poles. Three large groups, or cells, in each hemisphere help to circulate this air within the lowest part of the atmosphere, the troposphere. Therefore, the jet stream exists largely because of a difference in heat, which in the northern hemisphere means cold air on the northern side of the jet stream and warm air to the south.