Man With Beard

Op runs for T144 (Wednesday). Spot the odd one out! Brief northerly on Thursday for all - SW areas not particularly affected But High Pressure is back by Friday and the northerly is cut off. A swift recovery of temps would follow in the days after due to the continuing strength of the sun, I'd think, though the ECM/GFS actually leave a small gate open for the Atlantic within a couple of days after these charts?

Completely agree William - looks to me like things will improve rapidly by the end of next week - starting cool but would warm up quickly if a HP cell gets reasonably close, it's early August after all!

Let me get this straight ... are you suggesting the ECM is wrong??

Yes real surprise this one, UKMO warm and sunny on Tuesday GFS nearer to this idea than it was, though more of a northerly GEM has the cool snap but by Thursday High Pressure is back in charge

ok that's another way of looking at it!! By the way, the 06Z ensemble swings even further from the trough scenario by next Friday - a very decent 1025mb mean pressure nudging in - in fact, by Saturday (T240), 12 out of 21 members have already progressed well beyond the mean chart and have high pressure either over us, or to our south, or east - wouldn't be long before a warm up after that. Mind you, the GFS 06Z does have a reputation for being the most progressive...

That has to be the most depressing August chart I have ever seen. Would it be colder than December 2015? Good news is the ensembles for both ECM and GFS - both much, much more seasonal than their ops for the end of next week: though not particularly warm. Look at that GEFS one - the 8C line close to the Med - so it won't just be us in jumpers!!

Mark I am working on a little research comparing the new GFS and ECM at 500mb specifically for central England, and I'm finding it's not as clear cut as the official N Atlantic stats would suggest (posted above) - when i add up all the total variances from the actual, the GFS ends up very slightly more accurate at T144. But I bet we're hoping this morning's GFS will be one of those old joke runs, with the trough stuck to our east seemingly forever - well hope is easy to find on its own ensembles this morning where by D10 it is a hopeless outlier - most ensemble runs either pushing the Azores High closer, or ... building High pressure over the top into Scandinavia ... and so the Glossea forecast for mid-August appears on the ensembles at last!

GEFS 06Z at T240 today (Friday 12th August). This is the mean: Almost all ensemble members have that high pressure in the mid-Atlantic. 13 out of 21 run have some sort of North Sea/Scandi trough, so a sizeable number but not all. What the mean doesn't show, though, is 8 out of 21 runs have high pressure being the main feature over the UK itself, in various forms but summed up in this one: - which isn't totally unreasonable given the mean chart and wouldn't be a bad result at all - not hot, but pleasant. (carry this run on through FI and it doesn't collapse too quickly either) This kind of scenario has gone from the form horse to the dark horse in the past 48 hours, but it's still there, and there's a lot of water to go under the bridge before then. So not a lost cause for a summery mid-August yet.

Pretty solid agreement on GEFS and ECM mean chart that, by next Wednesday, a cold front will have passed through, with cooler, showery conditions for all - best in S. No decent sign of settled weather after that. The low headed towards us on Monday/Tuesday, not picked up until the last 36 hours, has killed the chances of a longer spell of settled weather next week, unfortunately. To be fair, the ECM ensembles never really got on board with the UK High idea, so it was never in the bag.

They do seem to be a day or so behind - 36 hours ago the settled card looked quite good but D10-D15 now looking a bit of a lottery with just a brief topple from the mid-Atlantic high ECM really has been all over place recently - having moved towards the GFS in the past 24 hours it now goes way beyond it with a mega-Scandi trough at T192. I think we're pretty set until Monday, after that, clearly less settled but not sure how much - HP could still get a bit closer from the W as the week goes on

GFS continues to be hot for the weekend and Monday over most of England, could 30C be reached again? everyone much cooler by midweek as a slow clearing low drags a NWly in its wake Sadly the second low moving in on Tuesday has put paid to height rises taking over in northern areas - for this run at least. Probably best chance for good weather up north in next seven days is that storm tracking further towards Iceland. ECM was a bit better for this yesterday, hopefully it will repeat this morning.

This is what I posted last Tuesday, with the charts forecasting for the next Monday. At that stage, T288 - now T156 The reason I'm posting this again is just to show - the ensembles CAN be useful guide even way out into the distance - IF (and this is a big "if") - there is strong clustering around a certain pattern. It's not the mean that helps, it's the existence of a large cluster (say 70% of the runs or more). Also, the presence of very warm ensembles is significant, as you rarely get more than a couple at a time out to T300. Perbutation 1 (the second post in the chart above) seemed fairly representative at the time. Aside the trough to the north - it was very, very close to what we're now forecast to get in the more reliable range: p.s. Sparky - ensembles for Aug 12-19 currently all over the place so very low confidence on what might happen that week just yet, IMO!!

Take a quick look at the GEM before you have your dinner. 18C uppers over the UK for 48 hours Sunday/Monday. Overdone? Maybe. But BBQ weather all the same!

It's a topsy-turvy day on the models so far. Some heat for the weekend still well on the cards - 27/28C looking highly likely in Eastern England over two or three days. But on the GEFS 06Z, by Tuesday next week the secondary depression totally scuppers the potential for a UK high, and leaves us in NWlys - the High stays painfully close in the Atlantic but not fun for Northern and Eastern areas in particular. What the mean doesn't show is that most runs have some sort of low pressure or trough in the North Sea: Most runs do eventually topple the Azores High into the UK but because its northwards progress was interrupted by the secondary low, it topples over the south rather than the north - much more vulnerable for flattening by the Atlantic jet. Mind you, with all the different modelling around this morning, that seems a lifetime away at the moment. I'm not discounting all of the runs with a settled outcome from yesterday or this morning yet at all. After all, just a couple of nights ago, the models didn't even have this mini-heatwave for Friday-Monday showing.

I must agree. No certainty for sure, but no sign?? He obviously doesn't spend as long as we do on the models ... Still a bit of daylight between the ensemble means this morning but wouldn't expect anything desperately unsettled from these, and quite possibly high pressure dominated with a W or NW flow The GEM looks a good fit in all honesty - which would be: hot for most at the weekend, slow breakdown from the north next Monday/Tuesday (still hot in the south), a weak breakdown further south for mid-week (possibly rainless), and a cooler high pressure builds back in behind for all by the end of next week. Sounds pretty reasonable to me - but beyond a hot weekend, still a few options on the table for next week pretty much as I supposed in my post yesterday evening.

Yes heatwave conditions from the ECM, especially in the south doesn't fit in the ensembles as far as the mid-Atlantic is concerned though, so low confidence on that one. Doesn't mean it's wrong. Here's one that does fit in with the ensembles, on the more pessimistic side it must be said - the GFS at T192 The GEM - somewhere between the two? All models seem agreed now on a hot weekend for the south - possibly into N England / S Scotland too but it's touch and go for them

That's a highly dodgy run. First am I right in thinking it beefs up that mid-Atlantic low out of pretty much nothing - almost in tropical fashion? Secondly, yes you can see a breakdown from the north coming by T216 but the transition to T240?

We have a 1030mb high on the mean chart by D9: The 1030mb mark on the GEFS mean has been significant for me over the past couple of years, as I take it to mean very high confidence that it will actually happen - I used it successfully to predict two weeks of mild weather last November due to a 1030mb mean high over Eastern Europe out to T300. So I'm now going to assume that there will be a high in the position shown on the chart above, for two days before and two days after. This is probably close enough to affect the UK, but not quite - I'd prefer to see it just a little nearer at least to ensure a fully settled week. As far as the UK is concerned, I think it leaves one greater possibility and two lesser possibilities. The greater possibility is that the high is close enough to the UK to affect it all week, and we do indeed end up with a nationwide anticyclonic spell of at least four days, probably more (the south will already have begun this coming weekend) - winds will originate west or north-west, so warm rather than hot and perhaps even a little chilly first thing in the morning. But lots of sunshine. One lesser possibility is the high is squashed slightly by the jet and disturbances do keep getting through on a westerly flow, but weakened significantly by the presence of High pressure nearby, so their significance is much less compared to recent weeks. The final lesser possibility is the high retracts a little west from where it is, and a trough could set up over Scandi, allowing a northerly flow to set in. In this scenario, west would be best and still probably settled, but much cooler. One thing that looks very unlikely on the chart above is a continental influence - that would seem to be out for the duration of the week - maybe at the beginning of end of the week. So I'm not sure it will ever quite be hot enough to be called a heatwave. Unless that 1030mb centre can drift a little east in coming days, as the op run does...? So not home and dry with the settled spell just yet - but odds looking pretty good for much more drier and sunnier weather in places like N Ireland than for some time.

Can I just make a point while we wait for the next installments of the model show (this is in addition to your post, not against it, Karl!) - IF we end up with a scenario like the GFS is showing at T192 getting to T144, then this would have a MUCH better chance of leading to a settled outcome over the UK than the Azores High "poke your nose in from the south west" charts. The latter allows the jet to flatten the pattern southwards enough to miss us. The former blocks the Atlantic out, and any flattening of the pattern only pushes the High further over us. The risk then is even further retrogression to a full on Greenland High, but that would be an almighty move from this stage. So what the GFS is showing is a far better route to more sustainable summery weather. It would be good to have the ECM on board but not essential until T144 as in my opinion the GFS will usually be more accurate when dealing with heights around Greenland. Still, needs to be showing in 48 hours time really to be taken too seriously.

GFS 06Z - best run of the summer? Very good for the south from 5th August a good week, and the north joins in by the 8th too

Sorry for brief response Knocker, was putting kids to bed. Yes, i was referring to op runs. On yesterday's 00z the Atlantic low train hinders the northwards progress of the Azores High into the mid-Atlantic, preventing cooler air sinking south from Greenland. Now that may be a temporary delay but clearly a very different outcome from the 12z. But usually, a forced delay does affect things further down the line, even if just positioning. Upper or surface air? Well, I rarely see one working without the other - here, a small upper trough accompanied the extra Atlantic low - which promoted a rise in pressure ahead of it. Anyway, onto today. Ignoring temperature, the latter stages of GFS is a holy grail run for many northern sun lovers away from Western coasts, with a UK high at last for a few days. It manages a decent Saturday away from NW areas, as high pressure rises ahead of a rather menacing low for Sunday which goes through the north, probably affecting the south too. But beware - the UKMO keeps a flat pattern out till T144, which is changeable for all.

The difference between the ECM 00Z and 12Z at T240 illustrate my point.

A very simplistic view but I'd have to back the GFS over the ECM when it comes to mid-Atlantic heights, if the trends shown continue on each model - ECM too prone to overdo them in my subjective opinion. Of course the situation is complicated by a "will it won't it" on whether another low will get through the Atlantic train between T168-T216, which changes the game either way.

It's been a dramatic, tense, action-packed day on the models. It started with that quite promising ECM 00Z at T240, with an extra trough in the Atlantic holding back the forces of Greenland and allow the advance of the Euro heat army: before the ECM threw in perhaps the scariest T240 chart of the summer this evening - potentially as cold as could be three days after this as the low swings down from Iceland: The GFS, on the other hand, has been showing very good though not exceptionally hot weather after T200, and perhaps that proper anti-cyclone at last coming in. The GEM joins in: In the closer time-frame, it's touch and go for next weekend between trough and ridge domination. In contrast to yesterday, it is actually the deeper areas of low pressure leading to better high pressure scenarios for the 6th/7th Verdict? Come back tomorrow and look again

Indeed Knocker ... when pitched against last night's runs, the 00zs show we are quite a way from even pinning down T144. The unsettled and the warm/settled paths are separated by very little at the moment. All to play for as we head into August!