GFS continues with the theme of a Scandy High and low pressure developing to the south of the UK. Details will change, but there's some potential for some decent weather. Just hope it coincides with the weekend!

Oh, and this is a candidate for "If only it were January" chart of the summer:

The models are now fairly similar for 00z Saturday, but after that there's a lot of divergence regarding the details.

GFS still has LP development to the S with interesting consequences as it turns very warm but with thundery downpours about. In keeping with most recent op runs from the model, the low then undercuts the Scandi High with an extended period of warm to very warm easterlies affecting the UK.

ECM has the LP development to our SW, which would be fine except that a second, very weak low also develops near the UK and moves across Saturday into Sunday. Being such a shallow feature, I suppose some slow moving showers would be the extent of its impacts, but it sure is a pain. Things continue in a similar vein for Monday and Tuesday as the two shallow lows faff about in our vicinity. Eventually they lift out to the NE with a new Atlantic trough digging south far enough west to place us on the warm but increasingly unstable side.

GEM displays some similarities to GFS as of day 6, except that the Atlantic trough isn't lifting out NW, which results in it moving too close to our NW in the days to follow - unsettled with temps near average, above at times in the SE. 

UKMO has a fast moving shortwave feature that comes into the scene at day 4 and becomes a troublesome looking low to the SW by day 6. Given that the shortwave exists on no other output at day 4, it is disregarded at this time.

Clearly GFS is out on its own with the behaviour of the Atlantic trough days 5-7. This is due to an area of low heights over SW Greenland interacting with LP exiting Canada on day 5 to bring about development of a marked trough that merges with the one to the NW of the UK, getting 'pulled' NW int he process. The jet stream goes with it, leaving a cut-off low to our S which is then at the mercy of the Scandi High.

The other models simply do not have this cold pool. Could GFS be misinterpreting the elevated cold air associated with high terrain over Greenland as an area of low heights associated with instability? Or could it be spotting some genuine potential for that cold air to be a catalyst for trough development?

Well here's the thing - ECM for example certainly had that cold pool on last night's 12z. Yet it wasn't there on yesterday's 00z. Yet it was there on the previous 12z. I can also see the cold pool to some extent on the UKMO 12z of yesterday.

So what gives? I wish I knew 

Anyway, current guidance suggests a high risk of showers for the weekend, offsetting what's likely to be above average temperatures across the SE'rn third at least... with any luck the higher temps will be more widespread and the showers less so, but I'm keeping my hopes relatively subdued this morning.

I did spot the lack of ensemble support for GFS last night, but was hoping that they were just struggling to identify the potential due to lower resolution (but is that even the case these days?). Perhaps that was a bit naive... the issue was probably more to do with this Greenland cold pool, as it clearly is this morning.

http://www.wetterzentrale.de/pics/Rtavn1681.gif

Yep a stunning Summer chart

You may miss the worst of it Edinburgh (although it will probably be a rather dreich day) but up here it looks vile with the models going for accumulations of anything between 35 and up to 60mm of rain locally. Not a nice day for mid-August (or any other time of the year!)

We're well past high summer now.

The Met/o 144hs is unsettled to.

UKMO looks way too progressive days 5-6, or at least I really hope it is!

ECM dives a shortwave low to our SW for the weekend, which places Sunday on a knife-edge for the Super Car Showdown at Beaulieu. That was a washout last year... surely it can't be the same again this year 

GFS has the same shortwave and similar timing, but also develops the would-be cut-off low to the SE of the UK. As it is, with the jet now surging across to the UK from the NW instead of diving south west of Iberia (turbocharged by the N. Atlantic SSTs again...?), the low develops and lifts north at a hell of a pace. We actually get lucky, as the resultant heavy rain band misses us to the east, with just a few showers in a cool Atlantic airstream to contend with. An all-too common feature of summer 2015.

The failiure of this week's largely fine outlook under increasingly warm easterlies to materialise has rendered this summer the most disappointing I can remember. Not in absolute terms, considering that it's had some decent dry periods and reasonable temperatures at times, but relative to what the model output has frequently shown to be possible in a version of reality free of the turbocharged Atlantic jet.

http://max.nwstatic.co.uk/gfsimages/gfs.20150817/12/264/h850t850eu.png

For example, take this chart from the GFS 12z op run, which suggests a blast of hot air capable of delivering 30*C in some places. Factor in a stronger jet stream as the Atlantic SSTs are accounted for, and this becomes a spell of rain followed by cool Atlantic westerlies. Sound familiar?!

Back in 2007 and 2012, there were some teases as you'd expect, but usually well beyond the reliable timeframe and requiring a huge pot of luck to come off. This summer, downgrades have often waited until the 5-7 day range, and then come in great force, rendering once pleasant looking days a cloudy, rainy mess. We may well see it again with the above GFS solution - and the fairly similar ECM solution.

...and that's from this end of the country, which has escaped lightly compared to the north! 

I just hope that for once this month can give rather than take, and spare us from the wind and rain until Sunday 23rd is done and dusted.

Rant over! 

In terms of climate, I agree. There is nothing good about it. Nothing. Yes it's varied, but that variety all falls within the boundaries of mediocre. Awful weather this nation suffers on a virtually constant basis. 

GFS 00z restore the heat back this weekend and the stupid dartboard LP over the weekend had been push back forward and look not potent as before so need more runs to remove it completely and put back to 2 HP linking together with UK in the best place of nationwide settled period.  Can't see 990mb LP coming off in high summer month and just to turn up out of blue on the charts also dodgy.  Otherwise BH again looking superb and seem more guaranteed to come off because September is round the corner to deliver the 99.99% goods.  I haven't see any wall to wall sunshine since May here and probably will return in September.

There are options to move abroad and if you have relatives abroad they can sponsor you.  I and my wife had been officially sponsored from her brother in Chicago as he submit it last week.  It would take up to 10 years but at least I still have half of my life to reside there when time come in so in the meantime I would buy the apartment, move some stuff there and use it for long vacations and setting up my online business ready to live on.

The most incredible thing for me is all summer the models have been utterly useless beyond around 72 hours. For weeks and weeks, months even, we have rarely had weather pan out three days down the line as was initially projected. What this does do is show up, again, how pointless amateur long range forecasts are, and that would stretch to pro forecasts too were it not necessary to attempt them to advance.

That got me wondering if the models should now be scrapped if they cannot do it correctly, it was so badly performed last week when they put high 20's here on the same day but we getting high teens maxes instead.  Almost every week they show 28-30C in the 5-7 days range which was always come off most of the time before so far now never materialized for 2015.

HERE IS MY LATEST ANALYSIS USING DATA SUPPLIED BY THE NWP OUTPUT COVERING 5 OF THE WORLDS MOST POWERFUL WEATHER COMPUTERS ISSUED AT 08:00 ON TUESDAY AUG 18TH 2015.

THE CURRENT GENERAL SITUATION. A Low pressure area will move NW up the North sea filling later. Anoher Low's troughs will approach the West of the UK from the Atlantic tomorrow. An area of slack pressure will persist across the UK today.

http://www.wetterzentrale.de/pics/Rtavn001.gif

MODELS-2 WEEK HEADLINE Remaining somewhat mixed with a lot of dry weather for all but with occasional rain too at times.

THE GFS JET STREAM FORECAST The GFS Jet Stream Forecast shows the main arm of the flow moving SE over the Atlantic to the Pyrenees with a returning arm North over the North Sea. The flow simplifies later in the week with the main thrust NNE across the UK come the weekend. Then next week it weakens and relocates further to the NW for the latter stages of the period.

http://www.netweather.tv/index.cgi?action=jetstream

GFS OPERATIONAL The GFS Operational Run today shows High pressure to the NE. A deep depression given the time of year to the NW then swings troughs East across the UK through the latter stages of this week in a mild and muggy SW flow. Through the weekend and early nxt week Low pressure is shown to be in control of the weather for all with various centres near or over the UK. Thereafter the trend is for pressure to rise strongly across the UK in the second half of the run with High pressure and warm and settled conditions looking likely towards the end of the period and including the Bank Holiday weekend.

http://www.wetterzentrale.de/pics/Rtavn1441.gif

http://www.wetterzentrale.de/pics/Rtavn3841.gif

THE GFS CONTROL The GFS Control Run today shows a similar theme as the operational run through Week 1 but is less optimistic through Week 2 as it maintains Low pressure close to the South of the UK at times with rain or showers here while the North see the best of the dry weather under the influence of High pressure to the NE and East. The end of the run shows a slack and cooler Northerly over Britain ahead of a ridge of High pressure moving in from the West.

THE GFS CLUSTERS(14 Days) The GFS Clusters this morning show a split in members almost equal to one another. One half illustrates High pressure lying over or close to the UK with fine and dry conditions for most as a result while the other half of members show Low pressure up to the NW with Westerly winds and rain at times.

http://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en&MENU=0000000000&CONT=euro&MODELL=gefs&MODELLTYP=2&BASE=-&VAR=cpre&HH=372&ZOOM=0&ARCHIV=0&RES=0&WMO=&PERIOD=

UKMO UKMO today shows Low pressure up to the NW later this week and the weekend culminating into a nasty little Low swinging NE into Scotland to start next week. The net result will be rain or showers for most especially towards the North and West with the possibility of gales and heavy rain for many for a time early next week.

http://www.wetterzentrale.de/pics/Rukm1441.gif

THE FAX CHARTS The Fax Charts this morning show very changeable conditions developing later this week as troughs of Low pressure move in from the West and become hung up across Southern areas maintaining cloudy, humid and damp conditions for several days before fresher air is pushed East behind a cold front at the weekend. then a deepening Low is shown swinging towards Western Britain to end the 5 day period.

http://www.weathercharts.org/ukmomslp.htm#t120.

GEM GEM today also shows changeable weather in SW winds from tomorrow on for all areas but taking it's time to reach the extreme SE. This model too shows a rapidly deepening Low swinging into the UK to start next week with rain and gales possible. On the exit ofthis Low the pattern reverts to a NW/SE split in conditions with further changeable weather in SW winds for many but a lot of dry weather in the SE.

http://www.wetterzentrale.de/pics/Rgem2401.gif

NAVGEM NAVGEM doesn't show the active Low to start next week that most other output shows. What it does show is the parent Low to the NW later this week sinking South and East to lie across the UK a week from now ensuring all areas see rain or showers at times in generally West or cyclonic winds.

http://www.wetterzentrale.de/pics/Rnvg1681.gif.

ECM ECM this morning shows the deepening Low early next week replacing the previously changeable weather with occasional rain to something much more Autumnal for a time as gales and heavy rain sweep NE through all areas for a time. Thereafter a changeable regime remains under Low pressure close to or over Northern and Western Britain with rain at times, heavy and thundery on occasion as warm air flirts with the SE at times.

http://www.wetterzentrale.de/pics/Recm2401.gif

ECM 10 DAY MEAN The ECM 10 Day Mean Chart  from last evening shows Low pressure West of Scotland with SW winds across the UK. With pressure relatively Low across the UK in a SW flow some rain at times can be expected for all especially towards the North and West with the warmest weather still towards the SE though even here rain at times looks probable.

http://www.wetterzentrale.de/pics/Reem2401.gif

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The models are coming together in showing a rather deep Autumnal Low passing over the UK early next week with much indecision on specifics in the period that follows.

31 DAY HISTORICAL VERIFICATION STATS FOR GFS, UKMO & ECM The Verification Statistics of GFS, UKMO and ECM. This morning's verification statistics show ECM leading the way at 3 days with 95.8 pts followed by UKMO at 95.4 pts and GFS at 94.6pts. At 5 days ECM is stll king at 85.6 pts followed by UKMO at 84.8 and GFS at 82.9 pts. Then at 8 Days ECM still leads at 60.0 pts over GFS's 54.2 pts. Finally at Day 10 ECM leads GFS at 41.1 pts to 36.3 pts from GFS.
 
http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day3_PMSL_MSL_G2NHX.png

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day5_PMSL_MSL_G2NHX.png

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day8_PMSL_MSL_G2NHX.png

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day10_PMSL_MSL_G2NHX.prig
 
MY THOUGHTS Irrespective of weather events shown by the models for the coming two weeks the solar clock is ticking as we drift towards celestial Autumn. However, we have two weeks of summer left but somebody seems to have forgotten to tell the models as they have served up another cocktail of charts which in the later days of the run are as confused as ever on the likely weather in two weeks time. What they do agree on this morning unfortunately is that over the next 7 days or so the weather is going to turn more unsettled and eventuually very unsettled. A deep Low to the NW will become the dominant player of the UK weather from tomorrow as it pushes fronts across the UK from the West which then become slow moving near the South for several days. This means rain will march East across the UK from tomorrow but be slow to reach the far East and SE where it will stay warm and humid until the weekend. At the weekend a change to cooler and fresher conditions seem likely as a cold front clears East which makes way for the highlight of the model runs this morning which is the passage NE of a potentially deep and Autumnal looking Low early next week which depending on track and depth could give rise to copious rainfall and gales almost anywhere for a time. Then from that point on the models diverge with various options shown ranging from Westerly winds and the familiar NW/SE split re-establishing  to full blown High pressure lying across the UK to end the month with fine, warm and settled weather for all inclucing the Bank Holiday. So in a nutshell there is still a lot of fog to clear from the models and their projection for beyond a week of the present. Nevertheless there seems enough common ground between them to suggest that the Atlantic is most favoured to continue governing the weather at the end of the month with nothing particularly special being advocated in respect of very high temperatures to end Summer, at least on a UK wide scale. Interestingly the verification stats show that ECM remains the best throughout the 10 day period with a 60 pts success rate (the highest for 6 months) at Day 8 with GFS only clocking 54 pts. So those people who says all the models haven't got a clue need to look at the 10 Day mean Chart from ECM which despite the chopping and changing of other output in relatively short time spans this Summer ECM has maintained Low pressure up to the NW for what's seem to be an age this Summer at the 10 Day range and looking back on the weather realised this Summer it has been proved to be correct more often than not and nothing on this morning's output makes me think that synoptics in 10 Days time will look significantly different to what it shows again today. 

Next update from 09:00 Wednesday Aug 19th 2015

I agree with you Matty that short range forecasting has been unusually poor this Summer and this has been mostly due to very slack pressure patterns lying across the UK for much of the time. I have said in my reports many times that 'no one pressure system has had any overall control of the weather for the UK as a whole for what seems an age now. When pressure patterns are slack nowcasting becomes a nightmare as the normal progression of West to East weather across the UK is interrupted with what pressure systems there are behaving unexpectedly at short notice.

I can quantify these facts by highlighting the verification Stats at 8 days out which have reached a 6 month high from ECM at 60 for 8 Days out today. However, the short term verification Stats though naturally higher are less than what has been in the past. So while ECM has been as poor as the rest in the short term its longer term projections of the general synoptic pattern 8-10 days out has never been far from what occurred.

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day3_PMSL_MSL_G2NHX.png

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day8_PMSL_MSL_G2NHX.png

Really

Does the weather in the UK really upset you that much?

Interesting stats. Thank Martin 

That's the problem this summer though, warm,settled weather always seems to be "just around the corner" and never quite gets here.

Back from the heat and humidity of the Mediterranean to a UK weather pattern that appears to be spiralling downwards to a familiar late August autumnal pattern. IMO Mid August starts to signify the 'feel' of the change of the season. This year is no exception as I look out of the window at grey skies and a temperature of just 58F at 1pm on an August afternoon. Incredible to believe that real summer is 2 hours away on a plane.

A poor outlook with a deep low delivering a showery and windy SW'ly flow for next week.

I would agree with this. Models rarely spot on with specifics though they can give a good idea of general trends I think.

So there I was starting to write off Sunday as increasingly wet and windy based on recent trends up to the GFS 12z, but then along came a UKMO run that was missing the vicious low, with a vague setup across the UK for which surface conditions were anyone's guess. This has since been followed up by a very similar ECM run, which reveals the plume of very warm air to still be in place across all but the southwest corner as of Sunday noon...!

While this is more promising as far as temperatures go, it's still touch and go as to whether the breakdown advances far east enough to trash the Bournemouth Air Festival and Beaulieu Super Car Showdown. Judging by the kink in the isobar a little west of the 10*C 850hPa line on the ECM chart (down by the NW corner of France), I figure the frontal boundary is probably over Devon as of midday, with the two events mentioned either staying dry until evening... or being hammered by thunderstorms!

So typical that such an uncertain situation has emerged for this rather important weekend (but at least it's not a BH weekend as well!).

Searching for pleasant conditions in the meantime is a little easier going - there's scope for some across the eastern half of England and much of Scotland tomorrow morning, then for much of the day across pretty much all of the UK on Thursday despite a few showers being possible for eastern parts of England. 23-24*C looks possible in the E and SE if there's enough breaks in the cloud.

Friday brings a stalling frontal boundary to the southern half of England where it looks largely cloudy with a bit of rain around, but elsewhere it could be a decent sort of day with temps a few degrees into the 20's for the middle third of the UK. 

For Saturday, the guidance has shifted a little more in favour of a warm or very warm day for the SE as the frontal system moves back NW, nearer average for the rest of the UK, perhaps cool in the NW as the (now warm) front proves too stubborn to clear away entirely.

Then you have the massive question marks for Sunday. Here's hoping the rain holds off until Monday! 

The trough disruption which promised a lovely Saturday & possibly Sunday is totally missing from recent output, whilst the slack pressure over mainland Europe, that allowed the more southerly placed low to slide SE'wards is firmed up into higher pressure. Door slammed shut.

Saturday's looking a washout. Great.

ECM 12z looks okay for the weekend to me. GFS looks wet but warm - possibly thunderstorms as opposed to generic frontal rain.

Quite possibly a washout for some, but others may escape, with the southeast potentially very warm.

I know it can be hard when the output proves disappointing for your location, but let's aim to avoid 'IMBYism' if we can, please.  

Edit: nicely done LeedsLad, accounting for the other possibilities