Stormy Weather II

[vinteuil]

Just two remaining days to the Winter Solstice - after which time the days start lengthening once more...

... the evenings have already started to 'lengthen' here - by one minute, starting Tuesday 17 December. Sadly, the mornings will go on 'shortening' until Friday 27 December - that will be the 'worst' they get until early January, when things (slowly) get better - but slowly is the word : it's not until the second half of January that you really begin to appreciate the lengthening days...

[Serial_Apologist]

... the evenings have already started to 'lengthen' here - by one minute, starting Tuesday 17 December. Sadly, the mornings will go on 'shortening' until Friday 27 December - that will be the 'worst' they get until early January, when things (slowly) get better - but slowly is the word : it's not until the second half of January that you really begin to appreciate the lengthening days...

Yep. Also, in addition, it takes longer for average, or mean temperatures to rise degree by degree from their lowest, as from tomorrow until midway through Feb, to highest, mid-July. Average or mean minima taken even longer to climb, remaining at 3 C until mid-March. Sunshine does have a role especially during the first half of the year in making it feel warmer than in the shade. Not that 2024 was a particularly sunshine-filled year!

[oddoneout]

Quite a contrast temperature-wise the last two days, although both were windy, sunny and dry. Wednesday was mild(14 degrees max), very pleasant for my volunteer gardening stint and a good way to end before the Christmas site shutdown. Today the wind has swung round so down to low single digits, having nosedived during the night - not too nice for standing around waiting for buses as I had to do this morning for a hospital appointment.

[Serial_Apologist]

Quite a contrast temperature-wise the last two days, although both were windy, sunny and dry. Wednesday was mild(14 degrees max), very pleasant for my volunteer gardening stint and a good way to end before the Christmas site shutdown. Today the wind has swung round so down to low single digits, having nosedived during the night - not too nice for standing around waiting for buses as I had to do this morning for a hospital appointment.

Precisely how these big swings in temperature are coming about is of some interest in the meteorological world, if recent scientific papers I kind of half-understand are anything to go by. The so-called "Azores high" - a semi-permanent feature located over the named group of islands with tendencies to translocate north and south with the seasons - has been for some time observed to becoming positioned further north than had mostly been the case up to the 1980s, this being put down to climate change for all manner of complex reasons. More straightforwardly, this new positioning and enlarging of a feature which is of great importance in circulating north-bound transported warm air up into the northern Atlantic to affect neighbouring coastal regions, when put against the still very cold air masses to the north of the meteorologcal dividing lines, i.e. the frontal systems and associated depressions, which latter are thereby made correspondingly deeper, more wide-spreading and intense, makes for much longer "fetches", or in other words bigger distances in air flow travel. Air approaching Britain around this swollen Azores high has originated from much further south than was predominately the case 40 or 50 years ago other than in exceptional years which are now becoming more and more regular. Conversely too, air of polar origin approaching us from behind the much deeper depressions than previously, while not as cold as pre-climate change, (as evidence by Arctic ice shrinkage) is still at the present stage relatively cold in contrast. The resulting increased rainfall - that which is specific to the temperate latitudes* - and associated floods - is directly resultant on this increasing temperature gulf along the polar front which, in winter, we now experience as extreme temperature changes from day to day. America has it far worse, where huge landmass size trumps oceanic influence. In the Midwest they are currently going from heatwave forest fire to blizzard in matters of hours. Serves them right when not believing in (and actually contributing to) global warming!

*It should be added that rainfall amounts are in any case rising worldwide as a consequence of a warming troposphere's capacity for holding more moisture. Temperature contrasts across airmass (frontal) boundaries are an added factor.