Good evening. Here is the report on the 12 noon output from the big 5 tonight for today Friday August 16th 2013.
All models show a brief ridge of High pressure crossing the UK ahead of a set of fronts associated to a deep Low to the NW of the British Isles tomorrow. This crosses East to the North of Scotland over the weekend with spells of rain followed by showers for all. By Monday High pressure will be building towards the South and East of the UK while the North and West maintain cloudy weather at times with further occasional rain accentuated by the passage of a further small Low moving NE across the NW while filling rapidly.
GFS squeezes the life out of this feature settling the weather down over the UK as a whole with warm or very warm conditions developing for all by the latter stages of the week. The weather does look as though the chance of a few thundery showers grow by next weekend across the South before cooler and more unsettled conditions show signs of returning from the NW at times over the second half of the run.
The GFS Ensembles show a fine and warm period coming up with most members showing uppers well above average as the High moves up from the SW next week. Even in the North the weather will improve with time with plenty of warm members here too while temperatures are well above average here too.
The Jet Stream shows the flow migrating further North as we move through next week, a pattern that more or less is maintained even towards the outer reaches of reality.
UKMO tonight shows High pressure well established over the UK by next Thursday with fine, sunny and very warm conditions to be enjoyed for most if not all areas later next week and earlier in the South.
GEM still shows a rather shorter spell of warm weather as it quickly allows High pressure to recede away East late next week at the expense of a trough moving in from the West and setting up a cut off cool pool close to SW Britain late in the run with rain or thundery showers as a result towards these regions.
NAVGEM is looking reasonably good tonight with High pressure dominating the weather through next week. There is a phase around midweek when despite High pressure the weather may be just fair but by the end of the week all areas look like becoming warm and sunny.
ECM is a little between and betwixt this evening as it's the spoiler Low on Tuesday which tends to dilute the extent of the push of High pressure from the SW. There seems more of a slack pressure pattern with a puddle of cool uppers aloft which could set off a few showers in the warm or very warm conditions experienced at the surface. By the end of the run High pressure is maintained via a tenuous ridge across the UK. Some thundery showers could be experienced in the South leading up to the weekend before the toppling ridge on Day 10 holds the weather fine, dry and reasonably warm elsewhere before and to all areas at the end of the run.
In Summary there is a little indecision between the outputs tonight. There are some cracks appearing in the High pressure based pattern tonight which don't indicate a flawed outlook other than there may be more moisture injected aloft which could give rise to a few showers in among the very warm and suuny spells. This is mostly caused by the small Low moving NE across the NW early next week against rising pressure, the cold pool of which could get caught in the air above the UK. Longer term as always there are various ways the fine and warm spell could end, all feasible but there is equal chance that we could hold on to fine and warm conditions right out into September.
Martin G
Kilmersdon Radstock Bath Somerset