Good evening. Here is tonight's review of the midday outputs from GFS, UKMO, GEM, NAVGEM and ECM for today Monday January 13th 2014.
All models show a similar pattern with just small differences on specifics for the next 6-7 days. Low pressure remains the driving force of the UK weather over this period with tomorrow offering the best day's weather as a weak ridge crosses East over the UK. By Wednesday Low pressure sends troughs NE across the UK followed by further unsettled weather with rain or showers at times. With Low pressure becoming slack and slow moving over or close to the UK later in the week areas of rain and showers will be slow moving in lighter winds which while heavy and even thundery in places will affect only limited places with plenty of dry weather around too for some. Temperatures will be non problematic on the whole though some frost at night could develop under clear skies and light winds here and there.
GFS then shows next week with continuing changeable conditions with winds largely between West and NW bringing rain and showers at times with the heaviest rainfalls gradually transferring more towards the North and West with time. All this due to Low pressure areas continuing to cross East just to the North of the UK and sending associated rain bearing troughs across the nation with sunshine and showers in average temperatures.
The GFS Ensembles continue the very average levels that have become the norm for much of this Winter Season. With plenty of rainfall shown nationwide spread throughout the run the Atlantic flow of Low pressure and troughs remains stubbornly persistent for all parts of the UK hindering any chance of any major improvement in alleviating the water from flood plains anytime soon.
UKMO tonight ends it's run with a slack Westerly flow under Low pressure with some dry weather but also a fair chance of heavy showers or longer outbreaks of rain continuing to plague the UK with temperatures close to the average for mid January.
GEM maintains Low pressure close to or over the UK with rain and showers for all continuing throughout the run with some heavy rain at times and just brief drier spells from a transitory ridge early next week.
NAVGEM also shows deep Low pressure close to Southern Britain moving away slowly next week but maintaining showers or longer spells of rain in temperatures close to or a little below average.
ECM tonight shows a cold SE breeze developing early next week as Low pressure transfers position from being over the UK to slipping SE to the SW of the UK by midweek. Some heavy rain or showers is very likely for many before drier weather eases down from the North with frost by night becoming much more of an issue. By the end of the run slack Low pressure to the SW and equally slack High pressure to the North setting up something rather colder from the East with the risk of wintry showers in the South.
The ECM 9 and 10 Day Mean Charts continue the theme of this morning with the bias of members showing a UK based trough as the most likely scenario through the middle of next week with Low pressure to the NW through the UK to the Med and High pressure well to the SW and NE too far away to be of a direct influence to the UK.
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The Jet Stream forecast from GFS show the flow riding across the Atlantic and then turning SE to the SW of the UK then East across Southern Europe. This general pattern is maintained through the period of the output which is hardly surprising given the uniformity of conditions for the UK shown by tonight's model output.
In Summary tonight the weather remains very changeable with rain at times, some of which will be heavy and prolonged but with an equal mix of drier interludes shown by some charts too. Temperatures look like never straying far from the long term average for this time in Winter. ECM has thrown a curve ball with it's operational tonight enhancing the effects of rising pressure from the North and lower pressure to the South next week resulting in an Easterly flow and even the risk of a wintry shower or two should it verify.
Martin G
Kilmersdon Radstock Bath Somerset