Looking at the GFS ensembles (for the S Midlands) it's difficult to see what (cold loving) people are getting excited about - okay, a couple of colder days this week but then from the weekend onwards average or above average 850hPa temps right the way through. And generally dry. Looks like some fairly pleasant autumnal weather - great for misty mornings and mushrooms and lazing in the hazy afternoon sun.
Originally Posted by: Essan
I think I must be looking at different charts to you as I can't see anything 'generally' dry from the South Midlands and certainly not for London from tonight's GFS Ensembles from the weekend onwards.
http://www.jp2webdesign.co.uk/two/ensembles/
Anyway Good evening. Here is tonight's look at the 12 noon outputs from GFS, UKMO, GEM, NAVGEM and ECM for today Monday October 7th 2013.
All models continue to show a marked change in conditions as we go through the week. the current fine and dry weather across the South will be eroded by a band of rain and drizzle across Southern England tomorrow. Further North brighter skies will develop with some showers, heaviest in the far North. Through Wednesday and Thursday colder weather will extend South to all areas with a mixture of sunshine and showers to end the week with some heavy and thundery showers in places later in the week. This theme then continues through to the weekend with the showers becoming more prone to SE and Southern England in a cold NE breeze while the North stays dry, bright and rather chilly with frost and patchy fog likely at night.
GFS then shows a very unsettled second half to it's run tonight with Atlantic Low's eventually engaging with cold air flooding out of the Arctic to give rise to some explosive low pressure developments around or over the UK with strong winds approaching gales and heavy rain in very Autumnal and chilly conditions for all late in the run.
UKMO tonight shows the SE at risk of showers or rain at times through next weekend while many Northern and Western areas stay dry and bright by day with clear spells at night giving rise to frost and patchy fog in these areas.
GEM shows a very showery pattern across the South of the UK with High pressure to the North of the UK keeping Northern parts dry, bright and cool with some night mist, fog and frost. Pressure builds South late in the run with many areas becoming or staying dry with widespread fog problems night and morning and still chilly enough for frost at night where skies stay clear.
NAVGEM has Low pressure centres close to the South of England over the weekend and start to next week while the North stays dry and bright under a ridge of High pressure. At the end of the run it looks like the quiet and potentially chilly pattern remains with some frost and fog at night along with the odd shower especially in the South.
ECM tonight shows Low pressure to the South filling up at the start of next week with occasional rain or showers and rather cloudy skies slow to recover with slack winds across the UK. Late in the run the model shows Low pressure closing in towards the UK from the West with South and West Britain becoming more unsettled from the SW with rain at times.
The GFS Ensembles look distinctly unsettled tonight particularly through the second half of the run with plenty of rain opportunities highlighted. Temperatures depressed at first will recover to closer to average values soon after the coming weekend.
The Jet Stream tonight shows the flow to the North diving South over the UK around a depression close to SE England by the weekend. This weak but significant portion of the flow then dissolves away but the new flow passing over the Atlantic is then diverted South of Britain by High pressure over the Arctic through Week 2.
In Summary the weather will remain much cooler than currently after the inception of the colder weather on Wed/Thurs. However, despite this it will never be desperately cold but be particularly noticeable due to the duration of temperatures of current values and the strength of the northerly winds. As we move through next week it looks like the cold winds in the SE will subside and a period of slack pressure will ensue with a lot of dry and benign conditions with temperatures close to average. In the outer edges of reality there are some interesting dynamics shown from GFS with gales and heavy rain likely with ECM too showing an attempt at Low pressure feeding in off the Atlantic at the end of the run but as we all know 2 weeks is an age in model terms.
Edited by user
07 October 2013 19:26:54
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Reason: Not specified
Martin G
Kilmersdon Radstock Bath Somerset