Good evening and welcome to my evening review of the 12 noon outputs from GFS, UKMO, GEM, NAVGEM and ECM for today Friday November 8th 2013.
All models seem to be singing from the same hymn sheet now with regard to the pattern and sequence of events between now and the middle of the next week. An unstable Westerly flow is blowing across the UK and it has steadily become rather colder of late. This trend continues tonight and tomorrow with showers at times, mostly in the West with a longer spell of rain in the South tomorrow as a trough passes. This is then followed by a strong rise in pressure through Saturday night and Sunday allowing light winds and a frost to develop. Sunday will then be a cold and crisp Remembrance Day with long sunny spells only giving way to cloudier skies later from the West as an active warm front approaches. This crosses the UK Sunday night with a spell of wet and breezy weather for all. Conditions then improve slowly from the NW on Monday as a cold front slips SE but the South will remain cloudy and mild till very late in the day. Tuesday will be a bright and fresh day with some sunshine but it will feel chilly before strong winds, milder and duller weather with rain returns across many parts midweek heaviest over the North and West.
GFS then shows a change later in the week as another cold front moving SE over Britain delivers a spell of rain before clearer and colder conditions take hold under developing anticyclonic conditions by the weekend. From then on with slack pressure over the UK for some considerable time the path is set for cold or rather cold and foggy conditions to develop with frost in places too and fog lingering all day too in places. Late in the run things turn colder still has High pressure develops on the Northern flank of a Southward sinking depression over Iberia with an East flow developing across the South with occasional rain giving way to cold and misty conditions which will also be experienced over the North in the interim days.
UKMO closes it's run tonight with a cold Northerly flow, especially over the East as High pressure rests close to the SW of Ireland at 1040mbs. Some cold showers would be likely in the East for a time before the most likely scenario of rather cloudy benign conditions from off the North Atlantic developing over the days that follow with average temperatures.
GEM illustrates the UKMO pattern well tonight moving indeed forward to bring milder Atlantic winds to end next week prior to a cold front bringing a rinse and repeat pattern of alternating milder and colder weather with a little rain, chiefly over the North and East.
NAVGEM topples a ridge down over the UK from the NW and develops it into an elongated High pressure area lying West to East across Central England and on into Europe. Dry weather would develop for many and if clearances in cloud permit a good deal of mist and fog would likely form across central and Southern Britain by next weekend, stubborn to clear in the daytime and making it feel rather cold away from the milder far North.
ECM tonight shows High pressure held down to the SW in it's extended run because of too much energy in the Atlantic train to the North forcing any ridging back South and maintaining an overall mild feed of air across he British Isles with stronger winds in the North with rain bearing fronts crossing East here too on occasion.
The GFS Ensembles are trending downwards in temperature over the coming two weeks. we must take into account the natural seasonal fall off in average temperature is quite marked at this time of year so overall temperatures remain never far from the seasonal normal. With High pressure around on some of the members outputs including the operational run described here conditions at the surface don't always reflect the uppers above so there could be some cold and foggy weather to be found in among these ensembles.
The Jet Stream forecast is that the flow currently blowing across the UK is destined to pull Northward next week to run ENE well to the NW of Scotland and then down over Europe at least for a time.
In Summary tonight it's more of the same from the models with alternating milder and colder phases of weather when rain at times on fronts affect all areas at times but more frequently and meaningful over Northern Britain. There seems no way out of the current Atlantic bandwagon with High pressure at least moving in closer to SW Britain damping down the rain in the South next week but at the same time keeping any really cold weather bottled harmlessly well away from British shores for the time being.
Martin G
Kilmersdon Radstock Bath Somerset