It's not uncommon for weak ridges and troughs to battle it out for a time in July, giving often rather vague output that can be hard to draw much from.
The ECM 12z run has numerous lows in the order of 1010mb hanging around the UK. These weak features would mostly act to bring afternoon/evening showers, with little ability to drive frontal systems.
It seems to arise from a 'residual' jet flow heading SE from the Atlantic and through the UK, this slowly dissipating with time. As the main jet heads NE, the Atlantic train should in theory end up heading entirely NE in the end... which is what GFS shows at the longer range.
Hints of that do also exist on the ECM run.
UKMO doesn't go far enough to give much of a signal, but the day 6 chart does show the residual jet problem.
That JMA run finds lower 850hPa temps and heights to our NW than the other models, and this due to errors in the modelling of the temperatures across Greenland;
http://www.meteociel.fr/modeles/jma/runs/2014070412/J144-7.GIF?04-12
Minus 8 shown there...
http://www.meteociel.fr/modeles/ecmwf/archives/2014070412/ECM0-144.GIF
Nothing below the tiniest patch of minus 4 there.
It's something I've seen consistently present in the model, and when a trough develops to our NW, this tends to lead to the trough being overdone (thermal gradient too large = jet too strong = trough develops too much).
So to summarise, next week looks like seeing one or two weak areas of low pressure attempting to get in the way of the ridge from the Azores. After this, the ridge has a good chance of taking over, and seeing as my break in Wales finishes a week today, that ridge is almost guaranteed to stick around and produce the longest reliably fine spell of the summer
Originally Posted by: Stormchaser