HERE IS MY LATEST ANALYSIS FROM THE OUTPUTS OF THE WEATHER COMPUTER PREDICTION MODELS FOR TWO WEEKS FROM 8AM TODAY SATURDAY NOVEMBER 15TH 2014.
NEXT UPDATE SUNDAY NOVEMBER 16TH 08:00
THE CURRENT GENERAL SITUATION. A slack Low pressure lies to the South and west of the UK with light cyclonic airflow across the UK persisting. A slow moving trough remains slow moving over NE Scotland.
MODELS-2 WEEK HEADLINE Remaining largely unsettled with rain at times, especially in the NW while Southern and Eastern parts become drier and mild at times
THE JET STREAM ENSEMBLE FORECAST The GFS Jet Stream Ensemble forecast shows a very variable pattern over the coming two weeks with a split in the flow developing. One arm is then shown to cross east at high latitudes north of the UK while anorther arm lies to the South. Both arms of the flow interject at times from a ridging and troughing pattern and bows quite strong at times.
GFS OPERATIONAL The GFS operational this morning shows the general shift of synoptics to change from low pressure to the South and West of Britain over the next week to more like Low pressure to the North and West with a slow shift of rain emphasis moving more towards the North and West by next weekend in slack winds generally. In Week 2 High pressure crosses the UK with a fine dry and possibly foggy period before Low pressure returns down over the UK from the Atantic with outbreaks of rain and showers for all once more in near to average temperatures.
THE GFS PARALLEL RUN The GFS Parallel run shows an earlier influence of High pressure from the East and South through next week with dry and fine weatehr arriving from midweek with mist and fog patches at night and patchy frost too in mild South or SE flow by day. Through the second half of the run the pattern of High to the East and SE collapses as Low pressure moves in from the West bringing a return to wet and windy weather in average temperartures to end the run.
THE GFS ENSEMBLES. The GFS Ensembles show High pressure from the East influential to the UK from midweek for the rest of the run, suitably positioned at first to ptomote dry and fine weather from soon after midweek with a mild Southerly flow. Through Week 2 the orientation of the High to the East changes to allow firstly colder air to spread west over the UK and unsettled weather from low pressure to arrive at the end of the period with cold rain and wind moving up from the South then.
UKMO. UKMO today shows Low pressure to the SW midweek with a band of rain and fresh breezes on Wednesday giving way to benign and dry conditions later in the week as the Low fills leaving a slack SE flow and rather cloudy but dry conditions across the UK in average temperatures.
THE FAX CHARTS The Fax Charts show a complex structure of filling Low pressure ambling around the UK over the next 72 hours or so before a simplified pattern develops towards midweek as a more defined trough crosses the UK slowly from the West. The weather remains largely unsettled with rain or showers at times through the period in relatively light winds and average temperatures.
GEM GEM also shows a similar pattern to the rest next week with High pressure to the SE maintaining largely relatively mild conditions with the shift of influence from Atlantic fronts gradually becoming more focused towards Northern and Western Britain while the South and East see less rain and some drier interludes in between.
NAVGEM NAVGEM shows relatyively mild conditions too next week with occasional rain from weakening troughs before it shows a High pressure ridge developing over the South from the SW next weekend.
ECM ECM this morning shows pressure building steadily next week as with the other models the shift of the Atlantic influence moves more towards the North and West from midweek. Pressure will then become quite high from a belt stretching from the Azores to Europe with a long fetch SW flow developing over the UK and much of Northern Europe keeping any threat of cold air a long way from the UK and keeping relatively dry and benign conditions over the South and East of the UK with time.
THE ECM ENSEMBLES Not issued at time of publication of this report.
NOTABLE TREND CHANGES FROM PREVIOUS RUNS The trend continues to grow towards rising pressure to the East and South of the UK with the rain and wind influence becoming most prolific to the North and West of the UK rather than elsewhere.
MY THOUGHTS The models are now settling on a theme of keeping cold away from the UK as rising pressure to the South and East of the UK becomes dominant from soon after the middle of the coming week. While this news will not be welcome to those looking for something cold and wintry it will be very good news for those saturated areas that lie across western britain currently as it looks as though once we move out of the midweek period there will be much less rainfall for those areas affected and this will allow at least a window of opportunity for some drainage of river courses etc. As indicated earlier it doesn't look like becoming cold and frosty under this high pressure influence as the positioning of it is likely todraw some mild air North across the UK for a time and later a mild and cloudy SW flow seems more than likely. Though fog could become a problem if any clear skies prevail overnight frost will remain patchy at worst as cloud and upper air temperatures remain above average. There is a chance that the Atlantic influence will return to all areas late in the period as the High to the East or South collapses but at this range I wouldn't bank on it happening in any shown way this morning. So in a nutshell there seems little sign of Autumn 2014 going out on a cold note and the season once more will end up being a very mild and at times wet one with frosts rather less than average and day and night temperatures as a whole over the three months being well above average at times.
Martin G
Kilmersdon Radstock Bath Somerset