Heavy rain and flooding has been a feature of the first half of November 2019. The UK weather has turned a corner now to more settled conditions. The reasons for this lie out in the Atlantic.
Some 300 nautical miles south east of Cape Farewell (southern tip of Greenland) there is an intense area of low pressure. Analysed by the UKMO at 967 mb last night it is very intense. The lowest recorded pressure ever was in 1979 when Typhoon Tip brought us down to 870 mb, but that was in the tropics; 967 mb is very low for the mid-latitudes.
The marvellous website Earth.nullschool.net gives us the opportunity to investigate the winds around this low at different heights. Current flows for the surface and top of the atmosphere are as follows.
Often these patterns are different; different winds at different levels are what causes changes in weather patterns. The fact the winds is uniformly circling the depression at all levels makes this a more static pattern.
The UK is somewhat to the West of this enormous system. The graphics show an intense stream of air piling south over us at the top of the atmosphere. Whole regions of air are being forced downwards causing high pressure and settled weather.
High pressure in winter can bring sunshine or settled gloom with. Sunshine is accompanied by frosts at night.
October 2019 was a typical Autumnal month of mobile UK-Atlantic weather with a succession of depressions, fronts and high-pressure systems bringing unsettled and changeable weather. At the at the start of the month the ‘eyeballed’ mean low pressure track was to the North West, with depressions moving to the North East through the Iceland/Hebrides gaps trailing fronts across the country giving rain with some settled spells in between. As the month progressed, this track gradually moved south, as befits the transition of the seasons. Slower moving complex lows were centred over the UK on and around the 20th. These were followed by some more intense areas of high pressure responsible for the hard frost in Scotland at the end of the month.
Beach hut owners on the North Kent Coast acquired their plots in the full knowledge that the once if fifty year storm would reduce their hut to broken planks. In fact the last weather disaster in the folk memory was the great flood of 1953. In fact, the University of Brighton’s Screen Archives South East supplies some photographic evidence of the aftermath:
The Met Office’s UK Sea Level Projections to 2300 reports that “at some locations the 1 in 10,000-year flood event of today could be expected more than once per year by 2300”. This seems to be bad news for beach hut owners; the once in fifty year storm might be expected every week!
These new sea level projections developed by the Met Office Hadley Centre have been published in a report by the Environment Agency. They show continued rise beyond 2100 under all climate change scenarios.
Important news for all; not just beach huts at stake.
September 2019 started and ended with an unsettled westerly flow of fronts and depressions but enjoyed a more settled, high pressure dominated, spell in the middle. Slightly warmer than the long term (1981-2010) average, with a little more rain and sunshine than normal.