Good morning everyone. Here is the report on the midnight outputs of GFS, UKMO, GEM, NAVGEM, ECM and the Fax Charts for today Wednesday August 28th 2013.
All models show a weak ridge of High pressure across the UK. With a lot of moist air entrapped mist and low cloud will be extensive this morning clearing later. It will stay dry everywhere. A front is shown to approach the NW tonight and move SE weakening beyond recognition by tomorrow afternoon across Southern Britain followed by a slightly more active one on Friday. Cloud from the first front will reach the NW tonight with a little rain dying out as it moves SE tomorrow. The second front will take the same route though a little rain is possible for most as this one passes later on Friday. Cooler NW winds are then shown to affect the UK though the weekend with dry and bright weather in the South while the North sees scattered blustery showers, heavy and frequent in the extreme North.
The Fax Charts show a series of troughs moving SE over the next few days followed by fresher and cooler NW winds as High pressure slowly builds back from the SW at the end of the weekend and start to next week.
GFS then shows next week starting with fine weather across many areas and it could become warm again in the South briefly before a more changeable pattern is shown by midweek as Low pressure troughs feed down from the NW with showers and cooler conditions developing before the 2nd weekend. Through the remainder of the run low pressure gradually transfers to be to the SE of the UK with showers and longer spells of rain in the SE. Pressure is shown to build in the NW with dry and cool conditions here. This drier cooler air sinks SE to remaining parts at the end of the run while the North sees unsettled weather return with rain at times in a Westerly breeze.
The GFS Ensembles show the cool dip at the weekend less pronounced in the South now though still noticeable before a warm up is again predicted for next week. The north sees much more average conditions following this cool dip with rain at times in westerly winds. Later in the run there are indications that more members are wanting to show rainfall across the South too as low pressure begins to take control with near to or a fraction below uppers shown.
The Jet Stream shows the flow to the North of the UK currently before an arm of it dives SE from Iceland across the North and East of the UK and the North Sea at the weekend. It then flattens West to East across Scotland next week before slowly becoming disorganized across the UK, Europe and the Eastern Atlantic at the end of the output.
UKMO this morning shows a North/South divide across the UK next week with the north under a fresh to strong West or NW flow with some rain or showers at times. In the South though cooler than of late some fine and dry weather is still shown towards midweek with more cloud and just shorter sunnier interludes.
GEM today shows High pressure holding close to the South well into next week with any rain and wind reserved for more North locations until later next week when the South could also see some cooler and more changeable conditions develop as the influence of low pressure affecting the North extends further South with time.
NAVGEM today is probably the least progressive of the output this morning with the same theme as the others of Low pressure passing by to the North of the UK bringing the occasional trough SE across the UK with the risk of some rain, at least in the North. However, on this run the North too would see some fine and bright weather at times with temperatures close to average.
ECM this morning holds reasonable weather across the South early next week while the North sees some rain at times. From midweek on pressure falls universally over the UK with complex low pressure engulfing the UK at the end of the run. This would mean from midweek on all areas would see rain or showers, heavy at times almost anywhere with temperatures very close to the seasonal average.
In Summary the weather holds firm across the South well into next week with a cooler blip following patchy rain SE on Friday. In the north the trend is for maintained changeable weather with rain at times with much more wind than further South. The trend for later in the output almost without exception is for more unsettled weather to develop for all of the UK in association with a Jet stream moving on a more Southerly latutude than recently with ECM showing Low pressure over or near the UK and attendant rain or showers at times for all. It does look as though it will be a fair old time before any significant rainfall is recorded on a widespread scale across Southern Britain though.
Martin G
Kilmersdon Radstock Bath Somerset