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Last night's anomalies are not a great deal of help in the medium term and merely indicate that the evolution for next week, and even this weekend, are is a long way from being nailed down. The models appear to struggle when you have the three current components in the mix, namely the major trough to the north west, the Azores to the south west and, the fly in the ointment, a second trough that drops south east and forms a cut off low around Iberia. How this combination interacts and who gains ascendancy seems to cause no end of problems, As can be seen there is quite a difference between the GEFs and EPS Best I can come up with at the moment is the percentage play is for most to remain unsettled but the south may escape with the HP nudging around. Given all of this perhaps not worth looking further ahead but just to say there are no obvious sign of any deviation away from an upper westerly flow and little indication of a more settled regime. Today quite a pleasant day for most except the north until the fronts have finally cleared to the NE. Tonight the cold front will encroach from the west bringing some light showery rain as it traverses the country tomorrow. The gfs this morning really just emphasizes what I have said above, After a couple of reasonable days Thursday and Friday (N. Scotland excepted as per) our faithfull shallow low is still hanging around over Ireland but, more to the point, it's about to get an injection of life from the north west which is decidedly not good news as 24 hours later low pressure dominates and the the UK is in a strong showert westerly with more prolonged rain over Scotland. This continues through Sunday and after a very brief respite a deep low tracks NE to be 975mb north west of Scotland by 18z Monday with the associated fronts crossing the country and gales in Scotland. The low then slowly tracks east and fills a tad leaving the UK in the strong westerly airstream. I think I'll leave it there and just keep in mind that gfs was always making more of the trough than the others but 140kt jet over the UK is just taking the mick

The ecm predictably varies quite considerable from the gfs Saturday onwards but it has shifted to a much more unsettled outlook from the previous run. By 00z Saturday it also still has the old low in it's death throes just west of the Hebrides with the cut off low NW of Iberia. But from here although England and Wales remain fine on saturday, Scotland and NI are still pretty wet as the low finally loses identity The difference now from the previous run is the energy/trough tracking in from the NW doesn't allow any significant ridging from the Azores and thus Sunday becomes a showery for most with perhaps just the far south escaping. Monday in a showery westerly before the next system tracks rapidly north east to be over Stornoway by 00z Tuesday with heavy rain and gales in Scotland and N, Ireland. Oh and Sidney says hi on this bright and sunny morning to all those concerned about his welfare

Right, this stops now okay. If you want to take issue with another forum member then please keep it via a private conversation instead of putting it in here. Please keep to the models. Thank you

Got a couple of stills of a bolt from the Lewes / Brighton cell - was watching it with the missus just outside Guildford - man that was a HUGE flash!

Day 1 Convective Outlook VALID 06:00 UTC Tue 22 Aug 2017 - 05:59 UTC Wed 23 Aug 2017 ISSUED 14:25 UTC Tue 22 Aug 2017 ISSUED BY: Dan UPDATE 14:25 UTC Adjustments made to existing SLGT and LOW threat levels to expand the elevated thunderstorm risk farther south overnight, while a MDT has been introduced to highlight areas where elevated thunderstorms seem most likely (while acknowledging greater instability is found farther south). In general, high-res guidance continues to suggest increasing covering of thunderstorms from mid-evening over Northern Ireland into western fringes of Scotland and the Hebrides, the Theta-E plume then destabilising farther and farther south through the early hours as the cold front and upper forcing approaches from the west. Hints in several models of a few elevated thunderstorms developing ahead of this within the Theta-E ridge over the likes of Derbyshire / Nottinghamshire / Yorkshire / Lincolnshire during the early hours. Some elevated showers (of questionable depth) possible this evening over parts of East Anglia too... http://www.convectiveweather.co.uk/forecast.php?date=2017-08-22

Ah well, if I don't get anything I shall nonetheless be entertained by everyone's storm pictures and tales! Keep them coming and good luck everyone.

One photo from some lightning quite far away this evening:

Nice to see reports of thunder and lightning in the SE of England, albeit isolated atm, was not depicted on my forecast map, I had SW and central S England under general thunderstorm area. But not entirely surprised that mid-level destabilisation of warm moist plume is occurring given highest CAPE has been indicated toward S England but the general consensus from various quarters that the energy will be capped. Goes to show that models are still not great at simulating mid-level convection.

Can see this tower growing to my east.

You know the one thing that strikes me is that there is no real strong convection going on. ... Mind you exactly the same happened two years ago, and we got a cracking storm that evening. Lets see what happens.

Wind direction is coming from the southeast (france) and drawing up hot and humid air. I'm wondering if we may see any imports that develop in this hot air mass? Probably wishful thinking on my part (desperate for a storm after missing two this month over my house, and have yet to see any fork lightning this year at all).

I must say that this summer has taught me a lot about the power of westerly and easterly wind bursts over the Pacific and their downstream effect for the UK. In that context it's clear to see why modelling for ~10 days out is screwing the UK.

31 out of 51 ECM ensembles tonight backing the GEM/UKMO solution - a big increase on the previous two runs. Let's hope the GFS/ECM ops follow in the morning

Well, I'm going to bed shortly so I'll bid you all goodnight. Leaving the window a jar so if anything does come over I hopefully get woken. To echo what another user said (sorry, can't remember name) wake me at thunder o'clock. Goodnight all and good luck tonight.

I’ll be content with distant flashes of lightning tonight, just something to tide me over till next year.

Got some big flashes here in Godalming. Sat in pub garden with a pint enjoying the booms. lovely!

Had thunder in my part of Northern Ireland today from around 5 ish till just past 8. Storm was overhead at one point. Just set at the window during the main show, from around 7-8 and watched it Torrential rain :/

re-post to resize photos....looking SE at some decent Ac Cas turkey towers forming and from other directions, a mixture of Ac, Ac Cas, and cirrocumulus, all good signs of some mid-level instability

Sferic south of IOW!

Yes BB, It has been little better here. We have had odd glimpses of sun showing through the veil of cloud, but it has been predominately cloudy, but humid. It was not until about 17.30 hours that the sunny finally broke through after a few spots of rain. Certainly was not the day we had been promised. Kind Regards Dave

What a disappointing day. Dull and cloudy for most of the time, specks of drizzle in the air this morning, and the first glimpse of the sun not arriving until 15.30 (and disappearing again soon after). Max temp 20.2C. Poor effort!!

Nice. The image is small as you've got the white bitmap surrounding the data. Take it into paint and drag the grey borders on the bottom and the right to the edge of the data, then save. Then re-upload (if you want to!). That will fix the issue. Hope this helps.

Derbyshire, Notts, Yorkshire and Lincs all mentioned in Convective Weathers forecast, chance of Elevated thunderstorms early hours

Maybe this could be 28th May all over again, as that was not forecast to happen...

keeping an eye on northern coast of France at the moment

ECM ensembles back to being all over the place for the bank holiday. GEFS 00Z adamant on a return to less settled.

Morning @karyo The sky is changing rapidly around here... Lots and lots of fibreous convective clouds now appearing... Hopefully... Fingers crossed.

Well there are some elevated storms affecting devon... could be a good sign??

Well now a couple of days back from our trip to Austria and once again loved it. After two years in the Tyroll, a move further west to the Volburg (Swazenburg) was a good move as it opened up a lot more of the country to see, and also visit Switzerland, Germany and Lichtenstein. Weather started dull for a few days and then got progressively warmer to 27 on the last day, and we had three over head storms in 2 weeks! Amazing. The last was best of all with Lightning across the sky

Some elevated thundery showers affecting Cornwall and soon Devon atm

No need for dragging this thread down with sarcasm. It's great we have these brave rogues protecting fragile multinationals from those greedy, all-powerful, gravy-train scientists. The world would be such a heartless, dangerous, polluted, backward place otherwise.

http://www.bbc.co.uk/news/uk-scotland-highlands-islands-41001234

Morning all - Proof this morning that a good looking chart does not guarantee good weather - who would have thought so much cloud and drizzle/rain would come from this? On to the Bank Holiday debacle. The very firm split remains this morning, except that the ECM has moved part-way towards the GFS, leaving the GEM/UKMO to campaign for a more settled outcome alone: The fact the UKMO is consistently promoting such a chart is encouraging, seeing as it is often quite good when dealing with the cut-off low to the SW. The ensembles are of little help. Both last night's and this morning's ECM ensembles are very mixed: Some encouragement in that the most UKMO-like cluster has grown overnight (from cluster 5 to cluster 1), and the most horrible clusters have reduced in size and number. Added that last night's ECM op being in a completely different cluster to this morning's ECM op, and given the general GFS/UKMO stand-off, there really isn't enough information available to call the bank holiday yet at all. Let's hope for more of a coming together on the 12Z runs. A little sightly further ahead, and it's pretty clear that a deep trough is going to form. The question is how much of the UK it will affect by the middle of next week. The ECM ensembles leaves its options open: while the GEFS looks far less settled, and does not have a cluster with heights to the east:

The current state of the sky around here at the moment... To be honest, I've seen better... But I've also seen much worse. The sun is quite warm though... Fingers crossed for later.

I assume your not home, or is beccles having its own micro climate day? Cos it's bright n sunny five miles down the road

Morning all Not much I can add to from my post last night, so to help back up what @Nick F, @Summer Sun, and @NUT have already posted about today, here are the very latest charts from the 06z run from the GFS. As always, good luck to everyone one with this, and lets hope that something goes bang later.

Yes , this is the best chance today of a decent hot day in August , some tentative signs of the cloud burning back from the southeast. Hopefully the bbq can make a rare appearance since early July this evening . http://meteoradar.co.uk/clouds-sun-UK-Ireland

Up to yesterday, the euro 4 was not picking up this activity at all.

Sadly it's all gone a bit Pete Tong again from the nice looking UKMO run yesterday... We had the high building in over the top of the cut off low, leading to some nice, warm settled weather. Today that's gone off the menu completely, and we have: Much more low pressure dominance, and the Jetstream picking up once again: We may just about scrape an acceptable bank holiday weekend, but looking dicey again after that. Plus by then we will be pretty much into September!

Oh so this is what a mini heatwave that the lads on the mod thread etc have been hanging on about looks like then!?

Storm & Convective Forecast Issued 2017-08-22 06:31:30 Valid: Tuesday 22 August 6am to Wednesday 23 August 6am Day 1 Convective / Storm Forecast Synopsis Upper and collocated surface low (the weakened remnants of ex-Hurricane Gert) will pull a plume of warm and humid air of sub-tropical origin across the UK, which will destabilise across Ireland/N. Ireland initially then across Scotland and N England Tuesday evening/night. … IRELAND, N. IRELAND, SCOTLAND, N ENGLAND and N WALES … A plume of warm and humid air advecting north across the British Isles on Tuesday, with wet-bulb potential (WBPT/Theta-w) values reaching 16-18C and characterised by steep lapse rates, will contribute to modest CAPE values reaching 300-700 j/kg ahead of cold front moving in across the far west during the evening and reaching N. Ireland, Wales and SW England early hours of Wednesday. This potentially unstable airmass will be capped across much of the UK during Tuesday, however, falling heights and cooling aloft with approach of upper low from the Atlantic combined with divergence in left exit of jet stream, shortwave trough and drier air aloft moving NE across the west will create large scale ascent which will destabilise the plume across Ireland/N Ireland initially in the afternoon … supporting development of heavy showers and thunderstorms, which will then develop or spread northeast across N England then the southern half of Scotland Tuesday evening and overnight into Wednesday morning as forcing moves NE. 30-40 knots of deep layer shear, strong upper level winds/divergence and linear forcing along/ahead of surface cold front will support organisation of convection/storms into clusters/line segments capable of producing torrential rainfall leading to flash-flooding, strong straight-line winds and hail. Increasing low level shear ahead of cold front and low LCLs (Lifted Condensation Levels or cloud bases) indicated across the west may support an isolated brief tornado too across Ireland, N. Ireland and NW England during diurnal heating cycle before risk drops after dark as surface/boundary layer becomes stable and storms become elevated. Have issued a MARGINAL risk, mainly for flooding, across Ireland, N Ireland, far N of Wales, N England and SW Scotland. ... SW / CENTRAL S ENGLAND ... There is a risk of some elevated heavy showers and thunderstorms across the above areas, mainly this morning before perhaps waning, though risk of isolated thunderstorms along S coastal areas through the day and into the evening as warm moist advection destabilises in mid-levels. Issued by: Nick Finnis

Day 2 Convective Outlook VALID 06:00 UTC Tue 22 Aug 2017 - 05:59 UTC Wed 23 Aug 2017 ISSUED 21:57 UTC Mon 21 Aug 2017 ISSUED BY: Dan Plume of high WBPT will be drawn northwards across the British Isles on Tuesday, ahead of an approaching Atlantic upper trough. Shortwaves running ahead of the main trough will provide the focus for mostly mid-level instability release, resulting in elevated showers and perhaps a few thunderstorms - the greatest risk of deeper, more widespread convection seems most likely on Tuesday evening / night as better forcing arrives from the southwest, destabilising the plume. Some uncertainty exists as to the extent of this destabilisation (especially considering the messy mix of stratiform vs convective precipitation), and hence how widespread lightning activity may be - a SLGT has been issued for now, though this could perhaps be upgraded locally to a MDT should confidence improve. In general, better forcing and shear will be found towards the NW, whilst instability will be more significant farther southeast. Should any convection become rooted in the boundary layer, more likely late afternoon/early evening, then there would be scope for an isolated tornado - particularly across northern parts of the Republic of Ireland into Northern Ireland. Some hail is also possible, but the greatest threat will probably be from localised surface water issues given embedded convective elements. http://www.convectiveweather.co.uk/forecast.php?date=2017-08-22

We didn't get September last year up here Probably was a little pesimistic with my post earlier Estofex maybe not looking too shabby............... http://www.estofex.org/cgi-bin/polygon/showforecast.cgi?text=yes&fcstfile=2017082306_201708212132_1_stormforecast.xml

Evening @NUT , do you not remember September last year? Evening @Chris.R I reckon that its more than worth keeping an eye on, as there is some pretty good Cape and LI values As always with storms a lot of this comes down to nowcasting on the day... But as long as this grey crud from today clears... Well, at the very least we should see some beautiful convective cloudscapes. I've included screen grabs from todays 12z run on the GFS... I'll have a look and post up whats showing tomorrow morning.

Now that is cool.

The Ecm 12z shows plenty of warm weather, especially across the southern half of the uk, very warm at times across the south with incursions of 564 dam which is nice to see. Definitely a more summery run with nothing autumnal about it..so once again there are better signs from some of the 12z output this evening...speaking of warmth, tomorrow will feel summery across england and wales with 23-25c widespread and 26-27c in parts of the s / se.

I'd never back GFS/GEFS over a combination of UKMO and ECM hence my interest in the ECM output but given the GEM 12z I had a feeling it would edge back toward a warmer and more settled outcome - and so it has, albeit a little tenuously. It manages to cut-off the low which is essentially what GFS has little interest in, but that low is a bit deeper and further north, which leaves us in a less certain state of improved weather conditions, despite the broader pattern being very similar; This run goes on to keep the jet a bit flatter than the 00z which makes a lot of difference to conditions across the S. half of the UK. This sort of thing - to answer @knocker's inquiry - being where the UKMO 12z differs notably from the ECM 00z; it has a flatter jet stream passing to the N of the UK, even more so than this 12z ECM has produced. It's not that big a difference on the face of it, but fine margins look to be at play with respect to the divide between warm/very warm weather with the odds favouring not much more than some diurnal shower formation and cooler, cloudier weather with a risk of spells of rain. It's not ideal by any means and we sure could do with the even flatter jet of the UKMO 12z, but (at least some) southerners may find it a satisfactory recovery in temperatures at least. Meanwhile Central Europe appears well placed for a late summer heatwave of considerable intensity for the time of year. As I'm paying a visit to the Balearic Isles in mid-September, seeing the 25*C 850 hPa isotherm edging toward there at the end of August does make me wonder what sort of overnight temperatures I might have to face given the warming effect on an already much warmer than usual Mediterranean. Of course with the knowledge of my time away in mind, it's probably wise to prepare for (relatively) exceptional heat to visit the UK in just under a month's time .

Would not surprise me if things might be capped down here, still guess we'll see in the wash as they say.

19C Last sub 11C September in 1952. Last sub 12C September in 1986. Last sub 13C September in 2015. Winter 2016/2017 is over before its even started.