Hi everyone. Here is the report on the 12 noon outputs from GFS, UKMO, GEM, NAVGEM and ECM for today Tuesday November 19th 2013.
All models show a deepening depression slipping SE down the North Sea then South across to Southern Europe on Thursday. Fronts associated with it will sweep SE across the UK tonight and tomorrow with rain for all and snow on the highest ground for a time. The cold front could be quite active with hail and squally winds ahead of a change to cold and bright weather with scattered showers, wintry in the North. Unsettled conditions then clear the South on Thursday with High pressure building quickly down over the UK from the NW where it then sits for the reliable future with dry, crisp days but with cold, frosty nights and the possibility of fog too, freezing in places.
GFS then shows High pressure meandering around in the vicinity of the British Isles until nearer the end of the run when Low pressure half-heartedly tries to give a semi-breakdown in conditions with some rain at times then. Temperatures overall will be on the cold side of average at the surface, often due to frost, mist and fog. Things may warm up a little late in the run as milder Atlantic winds show occasional success at moving into the UK from the West.
UKMO tonight shows High pressure over the South-western half of the UK with a slack Westerly flow developing over the North. Most areas will stay cold and dry with sunshine by day with frost and fog problems night and morning. The far North may see cloudier weather moving in off the Atlantic later restricting frosts and fog by night and raising daytime temperatures a little too.
GEM tonight also shows High pressure settling down near to SW parts of the UK through the latter end of the run. With Westerly winds rounding the Northern flank of the High there would be an infill of cloud from off the Atlantic first across the North and later the South too so after a cold and frosty start the weather would become milder but cloudier day and night but the threat of Anticyclonic gloom becomes a real possibility should this run evolve.
NAVGEM once more holds High pressure further to the North over Scotland or the Northern North Sea. The net result of this would be to keep the weather cold for all with a stronger Easterly flow over the South. This would make things feel very cold here with some sunshine at times but though frosty overnight fog would be less of a problem. Northern areas on the other hand would see plenty in the way of frost and fog as skies stay clear and winds stay light.
ECM tonight completes a very High pressure dominated set of model runs tonight as High pressure refuses to leave our shores gradually migrating to the East and SW but maintaining a ridge with it's axis West to east over the UK. As a result quiet weather will persist with frost and fog night and morning, slow to clear in places. Daytime temperatures may nudge up a degree or two later if fog clears and frosts become less harsh, especially towards the North as the Atlantic becomes poised to end the fine spell on Day 10.
The GFS Ensembles tonight show a lot of High pressure over the first 10 days though the NW may see some milder and more unsettled conditions next week. Later in the run the chances of this unsettled weather spreading to all areas increases with WNW winds likely to bring rain or sleet at times with snow on hills possible late in the period.
The Jet Stream is flowing directly South near the British Isles at the moment before it ridges High over the Atlantic setting up a blocked pattern and a High pressure over the UK by the weekend. Longer term there is a hint that it may change trajectory to allow a WNW to ESE flow across the North Atlantic and down over the UK.
In Summary the weather will be fine and dry for much of the period with High pressure remaining in close proximity to the UK. All models with the exception of NAVGEM do show a more Southerly axis to the High pressure belt tonight with a trend even further South late in the outputs as the Atlantic becomes more threatening and likely to invade our shores again with time.
Transcript taken from:-http://www.norton-radstockweather.co.uk/Model-Analysis(2859336).htm
Edited by user
Tuesday, November 19, 2013 7:58:55 PM
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Reason: Not specified
Martin G
Kilmersdon Radstock Bath Somerset