Good morning. Here is the report on the midnight outputs of GFS, UKMO, GEM, NAVGEM and ECM for today Thursday November 7th 2013.
All models show a somewhat showery Westerly flow across the UK now that the trough across the SE this morning continues to move away SE. This showery pattern lasts through until Saturday when a trough swings East and winds turn NW briefly with a ridge crossing East on Saturday night perhaps permitting a frost in inland locations as winds fall light. On Sunday a warm front crosses NE over Britain with dull and misty weather with drizzly rain for a time. Sunday night and Monday morning are then shown to be very mild and dull with another band of light rain pulling SE through the day on a weakening cold front to re-introduce colder and fresher conditions from the NW with scattered showers over the North.
GFS then shows quite benign conditions with Westerly winds over the UK around High pressure just to the South. Temperatures would recover to average or perhaps above in sheltered Eastern areas though the North could be subject to thicker cloud and occasional rain at times while the South might see patchy fog at night should skies clear and winds fall light. Then the pattern remains locked for a good portion of the later run with mostly dry and rather cloudy conditions predominating in the South while the North sees occasional spells of wind and rain. Temperatures would remain close to or above average until the end of the run when pressure building North over the Atlantic brings the threat of much colder air flooding South over all areas with rain and wintry showers and frosts at night right at the end of the run.
UKMO shows next Wednesday as quite quiet with High pressure close to the SW with an Atlantic feed of winds ushering in a lot of cloud from the West with some occasional rain to the NW while the South sees dry weather. Temperatures would not be far from average at this point.
GEM today shows a cool NW feed across Britain next Wednesday with milder air soon rounding the Northern flank of the High pressure to the South and bringing a period of mostly cloudy but dry weather in the South but occasional light rain over the North at times. Right at the end of the run winds freshen markedly especially in the North with gales and rain rushing East across these areas. Further South a cold front would bring a period of rain and wind followed by a sunshine and shower mix for all after Day 10.
NAVGEM brings another brief injection of milder air from the West towards midweek quickly followed by unsettled and wet weather spreading across all areas from the NW later as Low pressure sinks ESE over Northern areas. By next Thursday colder air is filtering South across Scotland as winds swing NE and as High pressure builds North through the Atlantic this looks destined to flood South over all areas late next week with wintry showers and frosts at night looking likely after the term of the run.
ECM shows a fast alternating pattern of milder and cloudy weather mixed with spells of colder and brighter weather with a NW breeze and showers, wintry over the North at times. It too shows a chance of colder air sinking South over the second weekend as high pressure builds North through the Atlantic with wintry showers developing from the North behind a spell of wind and rain for all.
The GFS Ensembles show a changeable pattern with rain at times for all areas with the heaviest rainfall to the North. Temperatures will be largely normal or somewhat above as uppers remain above average in the South for much of the run. Very late in the output there is an embryonic trend towards a pressure build North through the Atlantic which is supported by other output too and this could open the floodgates to the North for a big dip in temperatures between Day 10 and 15 depending on which model you view.
The Jet Sream continues to undulate over and around the vicinity of the British Isles over the coming week or so. Later on although reliability and accuracy falls away there is a tendency for the flow to want to shift further South and if this was to verify in a large way things could look rather different synoptically in a couple of weeks time.
In Summary this morning while this coming week remains as it has looked for some days now with High pressure building up towards the South with rain and wind becoming more infrequent the further South in the UK you go. The longer term output is looking a little more interesting this morning. It appears that High pressure may build North across the Atlantic later next week and beyond, perhaps towards Greenland. Should this verify, and it is still a very embryonic sign this morning the weather in 10-14 days time would shift towards much colder weather than we have sees so far this Autumn with the risk of sharp frosts greatly increased and the incidence of sleet or snow, in the form of showers also greatly enhanced over Northern Britain. We just need the following days outputs to grow this trend and maintain it's support throughout the various models and their ensembles.
Transcript taken from:-http://www.norton-ra...is(2859336).htm
Martin G
Kilmersdon Radstock Bath Somerset