A Period of Quiet November Weather

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.

UKMO Surface Analysis 180600Nov19

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.

250 mb wind 18 Nov 19
Surface Wind – 18 Nov 19

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.

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