Hi everyone. Here is tonight's attempt to look between the Weather models 12 noon outputs for today Friday December 20th 2013.
All models show another deep depression to the NW of the UK with a cold front slipping ESE across Southern and Eastern areas overnight leaving behind a cold and showery SW flow over northern and western areas while a wave travels NE along the cold front over the SE tomorrow delaying it's clearance until evening. By Sunday all areas will be under a rather colder and showery Westerly flow with some wintry showers over the hills and maintained very windy weather. On Monday the weather becomes particularly stormy everywhere as yet another unusually intense depression moves in close to NW Scotland. A series of troughs cross all areas through the day with heavy and persistent rain for much of the day clearing slowly SE later with severe gale or storm force winds giving rise to potential damage in places.
GFS then shows Christmas Eve as a windy and very showery day with gales and frequent showers for all with more persistent rain left over from Monday only clearing the SE slowly. Some of the showers will again be heavy and wintry in places , most frequent in the West. On Christmas Day and Boxing Day it looks like being somewhat less windy but rather cold with further showers and longer spells of rain or sleet, especially in the South. Thereafter up to the New Year yet another storm system similar to Christmas Eve's version brings heavy rain and severe gales to all areas followed by sunshine and showers yet again. As we move towards and over the New Year High pressure ridges towards the UK from a position North of the Azores and brings much less wet but breezy weather with more benign conditions over the South while rain becomes restricted towards the North.
UKMO tonight shows a wet and occasionally very windy Christmas especially on Christmas Eve. It will become rather cold with some snow showers over the hills at Christmas where a quieter period at the end of Christmas leads us into the approach of the next storm system on the 27th.
GEM tonight keeps deeply unsettled weather throughout the three day Christmas period with strong to gale or even severe gale force winds driving spells of rain and showers across the UK repeatedly over and beyond Christmas , falling as snow at times over the hills.
NAVGEM tonight also replicates GFS and UKMO's trend of seeing the back of one spell of stormy weather as we exit Christmas and enters into another as a new storm system piles in from the North Atlantic post Christmas with renewed gales and heavy rain.
ECM keeps the unsettled and sometimes stormy weather going well beyond Christmas and towards the New Year with plenty of rainfall and showery interludes with cold enough conditions at times for some snowfall over the hills especially over the Christmas season itself.
The GFS Ensembles maintain no signals for any really cold weather anytime soon with the general trend for the very wet first week slowly giving way to less wet conditions for the South later in the run as temperatures maintain average uppers. The operational was a warm outlier at the end with it's warm uppers blowing in around an Atlantic high.
The Jet Stream shows very little overall movement over the majority of the output time tonight though it does show some evidence of ridging North over the Atlantic around a displaced Azores High in the far reaches of the run.
In Summary there is a lot of very unsettled, wet and stormy weather to come over the next few weeks. Temperatures will fluctuate between a little above average during the rain bands to just below in the showery spells when some snow could be witnessed, especially over the hills and over the Christmas period itself. There is very little evidence of a reliable indication of the way out of this pattern with virtually no chance of any major changes this side of the New Year. The only evidence of change hinted at tonight is that the Jet flow be pushed back more towards the North again as High pressure builds again over Europe or the Azores though at 10-14 days out this theme will have to be maintained and built upon in future runs to gain any credibility.
Edited by user
20 December 2013 20:09:36
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Reason: Not specified
Martin G
Kilmersdon Radstock Bath Somerset