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Yet another tricky potential thunderstorm breakdown coming up, so I thought I would put a few thoughts down about the different aspects I am looking at. The first scenario I am looking at is the possibilities tomorrow afternoon with a warm sector trough moving across the UK. Scenario 1. During tomorrow light low level winds will begin to swing round to come from a more maritime direction bringing in a little extra moisture. Above this is still the elevated mixed layer with a marked CAP or warm nose at around 800hpa to 850hpa. This CAP appears to be slightly weaker the further north in the UK you go. Forecast models don't appear to particularly agree about whether this CAP will go and far to often we have seen models predict storms based on knee deep high dew points. We have also seen high instability produce not even a speckle of rain because triggering is not in place or the CAP is stronger than forecast. The extra ingredient I am watching closely is the potential for a little wind convergence (maybe around Oxford) which may trigger a pulse storm. Hodographs are curved marked in the south of England but less so further North so supercell development initially is very questionable. With inflow being curved into the south of any pulse storm then there is potential for a pulse storm to develop a rear downdraft and slowly develop tornado potential. It is not clear cut and parameters are likely to change so the forecast at the minute would have to be classed as a very slight risk. Warm sector troughs in the UK are however one of the scenarios which can produce moderately severe storms in the UK. Best guess is that the east and north east would be favored for storms at the moment. Scenario 2 I looking at the cold front and low pressure system moving across the UK in the early hours of Thursday. We have marked vortcity advection, potential for very high cloud tops, but the timing is such that surface temperatures are low. I am thinking there might be a small window of opportunity where the front becomes rooted in the boundary layer sometime between 6am and 10am. So again this would be a very slight risk mainly in the East and North East due to timing. Summary Looks like both a forecasters delight and nightmare. Delight because they get to examine and explore charts and detail they would not normally do. Nightmare because the potential for getting it wrong is very high. My best guess is that for scenario 1 the high level cloud showing up in the warm sector on satellite images may put a damper on things. For scenario 2 then the vorticity driving this scenario looks concentrated further south on satellite images than I would have expected. When in doubt I tend to look at jet stream forecasts and upper level divergence and this looks fairly strong for the early hours of Thursday. I expect a lot more detail to come out as models re-align with actuals and at this point I cannot make an accurate assessment. I don't suppose this was much help, but might point to things to watch.

While the longer range modelling can have some credence, it's not the be all and end all.... For example....look what we had modelled for Sunday 18th June a couple of weeks back: Versus what we actually got (32c, heat and glorious sunshine): It's all but certain that the rest of June is going to be unsettled, but the next warm or hot spell can creep up on you quicker than you think!

I will happily settle for a rinse and repeat of the current pattern all summer long. A spell of cooler westerly upper flow is unavoidable, it would be delusional to think otherwise but I think the azores high will return again and again through July / August.

Well I've just read the synopsis on UKWW as regards tomorrow - and they know what they are talking about - and from the sounds of it anything tomorrow will be Peak District northwards - so the southern half of the UK can kiss goodbye to anything convective this month. Frankly ridiculous. I mean how hot does it need to be and for how ****ing long to get just one poxy storm down here

I know that to the newbie, these things look like a big mess of lines, but bear with me. The following Skew-T shows a cap nicely on a very convective day (some of you may recognise the date and location*...), I chose this as it was the first one that came to my head that had a very noticeable cap. Concentrate on those two bold, black lines. The right one represents temperature, the left the dew point. The higher up on the graph, the higher up the observations are in the atmosphere (the pressure level is on the left hand side). It's basically a "slice" of the atmosphere. You can see at the bottom of these two black lines that they are very close together, representing a very moist surface layer. This maintains up to a level of around 850hPa, but we then suddenly see a change. The temperature line skews to the right, indicating an increase with temperature, and the dew point skews to the left, indicating a decrease in moisture. So we suddenly hit this, warm, dry layer - that's the cap. This cap essentially stops the warm, moist air at the surface from rising. That is, until the air has warmed and moistened to a sufficient extent that it eventually breaks the cap. *This was the day of the Moore F5 tornado in 1999. We will not be seeing that tomorrow I just want to stress!

In my years of model watching, I have never ever seen UK CAPE and LI values showing this at 24 hrs out I know these parameters mean little in isolation but my word, if something does initiate it'll have untold amounts of energy to draw from

Day 2 Convective Outlook VALID 06:00 UTC Wed 21 Jun 2017 - 05:59 UTC Thu 22 Jun 2017 ISSUED 20:58 UTC Tue 20 Jun 2017 ISSUED BY: Dan Broad upper ridging (and anticyclonic flow) will still be in place across much of the British Isles on Wednesday, but as an Atlantic upper trough approaches it will advect an EML (elevated mixed layer) above a very warm and reasonably moist surface layer (afternoon dewpoints near 19-21C, ignoring the GFS which continues to over-estimate surface dewpoints, and hence grossly exaggerates modelled CAPE). ---------------------------------------------------- Elevated thunderstorms will possibly be ongoing / developing at the beginning of this forecast period, especially over northern England and southern Scotland, with general areas of showery precipitation with embedded lightning moving erratically NE-wards across the remainder of Scotland. ---------------------------------------------------- Farther south, assuming plenty of insolation then strong heating will yield 2,000 - 3,000 Jkg-1 SBCAPE in a notably capped environment - the greatest instability developing during the second half of the afternoon and into the evening hours. Many areas will remain dry under such conditions, but it is just possible that enough forcing from a combination of sea breeze, topography, surface troughing and falling heights aloft during the evening hours may be able to overcome / erode the cap to allow explosive but probably fairly isolated thunderstorm development to occur. High-res models continue to offer little support for surface-based thunderstorms given the strength of the capping and dry layers in the mid-levels, but that said elements of medium-level instability release over northern England could become rooted in the boundary layer, and / or surface-based convection could develop. Given the lack of any useful guidance (aside from 12z ECMWF, GFS has been consistently too moist in surface layers on recent days and continues to overplay the thunderstorm risk) it becomes hard to highlight any specific areas at risk with any confidence - but overlapping of favourable ingredients would suggest one or two isolated but severe thunderstorms would be possible during the late afternoon, more especially evening, hours across N or E England. Such storms could rapidly organise into multicells or perhaps supercells, capable of producing damaging hail up to 4-5cm in diameter, strong gusts of wind and, if surface winds can remain ideally backed, perhaps also a tornado. A severe thunderstorm cannot be ruled out elsewhere in England, but in general capping is likely to be too strong to be overcome. It is quite possible that very little, if any, notable surface-based convection occurs - but worth stressing should it occur, then it could be quite noteworthy and potentially disruptive. ---------------------------------------------------- Overnight, rapid height falls as an upper trough approaches combined with a cold front will allow medium-level instability release to help generate some elevated deep convection with the potential for a few thunderstorms - the risk beginning over SW Britain initially, then running NE-wards with time through the early hours. The exact track, extent and timing is very uncertain at the moment depending on the phasing of the upper trough with residual high WBPT plumes across S Britain, and further updates / tweaks may be necessary to the forecast. http://www.convectiveweather.co.uk/forecast.php?date=2017-06-21#sthash.arAdUnhF.dpuf

Come on guys, it's been a good day of discussion on here. Are we really going for the toy throwing already? Tomorrow is a very conditional threat and it hasn't even occurred yet.

Here's another snap of the 2015 Supercell taken from my home.

2015 stands out immediately in my mind with the July 1st supercell, watching it roll in from the Goyt Valley and across Cheshire with lightning crashing around every few seconds and being fortunate to be in-situ along the southern dry-side so all the structure was evident. Even 2 hours after it had passed and moved up into Yorks/Lancs the lightning was still flicking away across the anvil on the northern horizon.

Not just high temperatures, look at these dew points, tropical values in some places

Wouldn't rule out a supercell at all looking at some predicted soundings. However, beware of such Facebook groups that are no better than the Daily Express!

Yes sounds totally un -inspiring and a waste of high Summer. Plenty of time for wet and windy weather in Autumn/Winter & Spring Even though I'm sneezing constantly with Hay fever & and getting very little sleep due to the heat, I would still take this weather over what the EC46 is saying any day of the week. Small price to pay for this glorious Summer weather.

This sounds nearly like an unforgettable experience I had when I was younger.... (Get ready for a hastily typed out story folks!) End of June, 1996. Moved to a village just outside Salisbury. Wall to wall blue skies, 30 degree day, hardly a breath of wind; so we had an impromptu house warming BBQ. Wall of cloud forms in the distance to the east, thunderstorm quickly builds and heads towards us. Black as the ace of spades and you could hear the thunder and feel the gust front as it approached. Luckily we had already finished the BBQ; but we hadn't even had a chance to unpack before the thunderstorm rolled over just after the sun had set; and then the power went out. Everything in boxes still; half the stuff still in the removal van; and couldn't find the torches to save out lives. No blinds were up so the Incredibly frequent lightning; nearly strobe lightning at times, illuminated the entire house. Could hardly hear ourselves think for the noise of the thunder overhead. Large hail too (that actually shattered greenhouses across eastern salisbury) and torrential rain causing a torrent down our garden and flooding the patio. Ended up all sleeping on two bare mattress and bedding just led on the floor of the living room as couldn't see to put the beds up and halving to cope with the lightning continuously illuminating the room through our hastily put up "sheet curtains". At 1am woken up by a collosal noise; never heard anything close to it in my entire life; which was the manor house opposite being struck by a huge bolt of lightning. Turned out the next day that the chimney in a top floor bedroom had been struck and collapsed into a bedroom, and that a relative of the manor house owners staying in that bedroom had nearly died in hospital from his injuries :s Was a terrifyingly bonkers experience and it lasted nearly all the night before subduing around 3/4am. Patio was still flooded come 8am in the morning. .....Guess that's what sparked my interest in the weather thinking about it!

to aid comparison, here are a few links that will help http://www.stratusdeck.co.uk/28th-june-2012 from Estofex "Storm Forecast Valid: Thu 28 Jun 2012 06:00 to Fri 29 Jun 2012 06:00 UTC Issued: Wed 27 Jun 2012 22:28 Forecaster: GATZEN A level 2 was issued for the Benelux countries mainly for large hail and severe wind gusts. A level 1 was issued for portions of the northern British Isles mainly for tornadoes. A level 1 was issued for the central and southern British Isles mainly for large hail. SYNOPSIS An Atlantic trough moves into western Europe pushing a ridge into central Europe. An elevated mixed layer currently across France will spread north-eastward on Thursday, and rich boundary-layer moisture is expected underneath the cap from eastern France to eastern England and the Benelux countries. Over eastern Europe, rather cool/dry air will remain. DISCUSSION The Benelux region The nose of the warm low-level air will move into the Benelux countries ahead of the surface cold front. Moisture pooling and diurnal heating will result in CAPE around 2000 J/kg given the elevated mixed layer spreading northward. Additionally, strong vertical wind shear will be in place. Favorably veering profiles and rather isolated convection in the afternoon hours pose a threat of supercells capable of producing large or very large hail and maybe a tornado. Later in the period, a linear MSC may develop ahead of the cold front. The increasing low-level jet is forecast to increase the potential of severe wind gusts with this MCS that will spread into western Germany. Excessive rain is also not ruled out. British Isles Warm air advection will continue during the night and morning hours from England into Scotland. This warm air is characterized by steep mid-level lapse rates. The warm air advection will increase, and a low-level jet is expected to strengthen on Thursday ahead of the approaching cold front. Latest satellite images indicate widespread convective/stratiform clouds spreading eastward ahead of the approaching trough and associated jet streak. Until the morning hours, these clouds will spread across much of the forecast area. During the day, especially the southern portions will be placed below the anticyclonic flank of the approaching jet streak, and weak forcing may result in rather strong daytime heating. Furthern north, QG forcing will be stronger. Elevated storms in the warm air advection regime may root to the boundary-layer in the noon and afternoon hours. Storm motion vectors close to the cold front are expected to result in a squall line with excessive rain the main threat. The severe wind threat is expected to be rather low given the expected slow propagation of the squall line. Further north, storms are expected to be more isolated. Although instability will be weak, these storms may organize given strong vertical wind shear. Mesocyclones will pose a threat of tornadoes. Across the southern British Isles, weak QG forcing will remain through-out the period. Along the cold front, some storms may evolve especially during the the second half of the day, when low-level heating and rather rich moisture will result in CAPE of 1000 J/kg. Strong vertical wind shear will overlap with this instability, and storms that form will rapidly organize. The potential of supercells is expected to decrease from the west during the day, and mostly multicells are forecast, capable of producing large hail and strong to severe wind gusts. However, supercells are not ruled out especially across the eastern portions where larger hodographs will persist well into the afternoon hours ahead of the cold front. Isolated very large hail may be possible when supercells indeed will form. The convective activity will decay during the evening hours in the wake of the surface cold front." From Dan at convective weather (UKASF as it then was) Severe Forecaster: Dan Last Updated: 2012-06-27 21:58:00 Valid: 2012-06-28 00:00:00 - 2012-06-28 23:59:00 Areas Affected: SVR: SE Scotland/Borders, NE Eng, Yorkshire, E Mids, East Anglia MDT: NE Eng, Yorkshire, E Mids, N Cambs/W Norfolk SLGT: Majority of United Kingdom, excluding NW Highlands and N Isles Synopsis: Upper trough gradually approaches from the west, allowing a plume of high WBPT and very high ThetaE to advect northwards across Britain. Destabilisation will occur on the plume axis during the passage of a pronounced shortwave trough, with potential for severe convection over Lincolnshire, Cambridgeshire and Norfolk during the afternoon. Discussion: Several areas of interest exist during this forecast period, with varying levels of severity. From the start of the forecast period through to daylight, indications are that elevated thunderstorms will develop over the English Channel/move northwestwards from northern France as the moisture plume destabilises with the approach of a shortwave. These mid-level showers/storms will tend to merge as they cross SW England and across the Irish Sea to Ireland. >40kts DLS coupled with >25kts would suggest some organisation of such storms into multicells or elevated supercells, sustaining such storms for quite a long period of time. >800J/kg MLCAPE also highlights reasonably frequent lightning with these storms at first, although the exact interaction of such storms with long sea tracks leaves us with a cautious SLGT level for sferic coverage for the time being - this may be upgraded to MDT if necessary. Other than very heavy rain, with PWAT values near 36mm locally, generally due to the elevated nature of storms severe weather is unlikely. This general area of thundery rain will then move north across the Irish Sea, grazing both Ireland/Northern Ireland and western parts of Britain during the day on Thursday, with ever-decreasing values of MLCAPE. Nevertheless, it is quite probable that lightning activity will continue throughout the day as cells remain sustained with decent shear available. Across the rest of England and Wales, a few mid-level showers will migrate northwards later in the night and first thing Thursday morning, although significant WAA in the mid-levels will provide strong capping, thus most showers will be light with a low probability of thunder/lightning. Capping is strongest towards SE England, and weaker towards the NorthWest. Behind these showers, conditions should improve with some patchy insolation expected as cloud cover begins to break. Dewpoints of ~17C and surface temps of 22-27C are simulated by most models, and will be substantial enough to generate some surface-based convection. Initially this will take place over eastern England, east of the Pennines with the plume axis and approach of a shortwave, combined with topographical forcing. Initially numerous thunderstorms are forecast to develop from ~12z onwards, with forecast soundings suggesting ample shear (typically 40kts DLS, 30kts LLS) and some helicity (>300m^2/s^2). This would generate an environment, coupled with 1000-1300J/kg CAPE, capable of producing multicells or supercells, with the potential for a tornado. However, due to the weakly-capped environment it is likely that mass forced ascent will quickly merge such storms into a linear formation along the trough, eventually forming an MCS producing frequent lightning and possibly some large hail (locally >3cm). PWAT of up to 39mm also increases the risk of flooding from torrential downpours. This line will continue to move quickly northeastwards, wrapping back into eastern Scotland during the evening so increasing sferic activity is expected here during the evening. It is not clear where the southeastern edge of such line will be, with some inter-model disagreements. Current thinking is south Lincolnshire southwards will be in a more-capped environment, and here such storms that develop will be more scattered and less likely to merge into any linear structures. Indeed, by adjusting forecast soundings to realistic T and Td values, 1800-2000J/kg CAPE is potentially available, with a slight cap being broken by combination of rising LSTs and the approach of a shortwave. Thus, in a zone from northwest Essex to southern Lincolnshire, a few scattered surface-based thunderstorms are expected to form in the early-mid afternoon hours, rapidly moving northeastwards. Given such CAPE values, combined with >40kts DLS, >25kts LLS and >250m^2s^-2 helicity, then a few discrete supercells are possible, especially in southern Lincolnshire across The Fens to West Norfolk. Veering wind profiles with height, and a substantial increase in speed shear with height suggest the potential for one or two severe thunderstorms, with rotating mesocyclones. With forecast dry air aloft, such storms will be capable of producing hail 3-4cm in diameter (up to golf ball), frequent lightning, with local flooding possible given PWAT values approaching ~40mm, although fast storm-motion should ease this risk somewhat. If the cap can be broken to generate such storms, then this is borderline our threshold for EXTRMLY SVR. Low LCLs as a result of relatively low dewpoint depressions (generally ~7C) with such shear values poses a significant tornado risk. Convective gusts may be as high as 50-60mph, and outflow boundaries may pose a focus for breaking the cap downstream and generating new cells. Storms will rapidly move northeastwards, generally clearing by 18z. In SE England, capping appears to be too strong, and the surface flow not backed enough, to generate any noteworthy convection, although some uncertainty remains." hope those links and descriptions help!

Kind of a loaded gun situation today and tomorrow across England and Wales, yes we have impressive CAPE values of 1500-2500 j/kg, but a cold front and/or surface convergence + strong heating may not be enough to overcome the stout cap in place. The 12z Nottingham sounding shows a warm nose between 750 and 950mb which prevents heated parcels from rising to create CBs. However, greater forcing for ascent, cooling aloft and falling heights from the west tomorrow afternoon should better allow the cap to erode to allow storms to develop across central and eastern England. If you are relating to the SE's storm prospects, more of a stronger cap in place today and tomorrow due to closer proximity of upper high to the south over near continent, probably mean any storms staying north of London tomorrow. However, cold front forming over Wales and SW Wednesday night and continued height falls + large scale ascent may bring a threat of storms to the SE on Thursday morning before the fresher air arrives. My 2 day storm forecast on Netweather website here: http://www.netweather.tv/index.cgi?action=convective;sess=

Most'll likely think it's a super-efficient battery?

Parts of Lincolnshire are under a storm Almost quite a rude shape as well

Sometimes people are inclined to bring their own interpretation to a general comment on the EC46 means. I posted a general interpretation of the long wave pattern which within the stated time frame was mainly influenced by the Atlantic trough. This is forecast to ease as as we move further into July and the Azores HP becomes more prominent. No attempt was made vis detail but given this I consider wet and windy for any length of time unlikely. But that is just my opinion of course. Also given this I think it probably wise not to comment on the EC46 output in future.

Extended N Atlantic chart from UKMO brings Tropical Storm Bret into the equation. Only formed yesterday so the track is probably historical at this stage. Its future development and forecast track could throw a whole lot of different data into the models as early as 168t. Maybe one to watch ! C

Actually most of the Ecm 12z indicates plenty of warm weather for the south in particular with temps into the low 20's c occasionally very warm into the mid 20's ..not a cool unsettled washout by any means!

I've seen worse potential

Good example towards the end, she breaks through

I was just learning about long-exposure and ISO compensation so it's a little grainy, but here's my shot of the 01/07/15 supercell as it was somewhere close to Skipton, some 2hr after it had passed through here.

Looking on estofex, for 15:00 tomorrow if I'm reading this right, up to 4000j/kg CAPE. Hail as big as 6.0cm, equilibrium level (cloud tops) as low as -60 (promotes lightning activity) and reasonable wind shear. Without over-egging this, tomorrow could be a very extreme day for some. All the ingredients seem to be there, apart from as mentioned earlier, a sufficient trigger I.e a cold front/trough. All of this will be moving NE. Also worth noting, is that some more residual storm activity could well pop up during Thursday morning too over the Midlands. What an unusual setup this is.

If you're referring to 2014, there was a impressive low-topped supercell that day which passed through oxfordshire. Unfortunately, i don't have the GFS charts for that day, but here's the sounding and radar (i have more photos too, if anyone's interested). If those CAPE/Li values really are accurate for tomorrow, i can only imagine the storms it could support.

That's regarded as extreme in the US. Unreal.

So tomorrow looks like being the hottest June day in 40 years since the magnificent heatwave of 1976

Storm & Convective Forecast Issued 2017-06-20 12:03:56 Valid: 20/06/17 12z to 22/06/17 06z DAYS 1 & 2 CONVECTIVE / STORM FORECAST - TUES 20TH & WEDS 21ST JUNE Synopsis An upper high which has persisted over southern Britain over recent days will begin to weaken and retreat SE during the rest of this week, as an upper trough approaches and moves in across western Britain by early Thursday. A surface high will drift east across northern Britain on Tuesday, pushing a weakening boundary southwards across England and Wales, separating hot and humid air to the south and cooler and fresher conditions to the north currently over Scotland. Surface convergence to the south of this boundary moving south may, with heating, trigger a few isolated afternoon storms. The same boundary will stall late Tuesday before drifting north as a warm front across northern Britain Tuesday night and through Wednesday, warm and humid plume returning north across below this warm front will likely destabilise across northern Britain early Wednesday, then further south later in the day. DAY 1 CONVECTIVE FORECAST Valid: Tuesday 12z to Wednesday 06z … WALES, MIDLANDS … Although forecast isolated storm development failed to materialise over last few days across England and Wales due to stout cap caused by upper high and warm/dry profiles, continued weakening of heights and slight cooling aloft from the NW in tandem with surface breeze convergence just to the south of boundary shifting south and stalling may breach the stout cap to allow a few isolated thunderstorms. Should a storm develop, it will tap into a reservoir of hot and humid air with CAPE values forecast in the order of 1000-1500 j/kg CAPE. High rainfall totals in a short-space of time leading to localised flooding with be the main threat from any storm that does develop, given high PWAT (Precipitable Water) values of 30-36mm pooling along convergence zones. High CAPE may also support sufficient buoyancy for isolated large hail too, though limited by lack of any appreciable vertical shear. Despite favourable parameters for storms, there are doubts that upper ridging will weaken enough to allow storms to develop, like last few days, so have refrained from severe probabilities for now. … N. IRELAND, N ENGLAND and S SCOTLAND … A shortwave trough moving NE on forward side of long wave trough approaching Ireland will likely cause large scale ascent of warm/moist conveyor returning north across the UK/EIRE Tuesday night, leading to an increase in mid-level convection and eventually the development of elevated thunderstorms by 06z Wednesday 30-50 knot SWly flow at 500mb and 30-40 knot 0-6km effective shear will support storm organisation into clusters, capable of isolated large hail, high rainfall totals leading to localised flooding, gusty winds and frequent cloud-to-ground lightning. Have issues a MARGINAL risk for severe weather across N England and Scotland. DAY 2 CONVECTIVE FORECAST Valid: Wednesday 06z to Thursday 06z … N IRELAND, far N of ENGLAND and SCOTLAND … Elevated thunderstorms are likely to be ongoing across N. Ireland, N England and Scotland during the morning with further storms perhaps developing through the day and moving NE, though they will be hit and miss in nature. Like the day 1 forecast, storms will be capable of hail, gusty winds and frequent lightning, though high rainfall totals leading to localised flooding will be main threat. Have carried over MARGINAL risk of severe weather before storms eventually clear east into the N Sea Wednesday evening. … N ENGLAND, MIDLANDS and E ENGLAND … Some elevated thunderstorms may be ongoing in the morning across the far north of England in association with destabilisation of warm moist plume returning north and destabilising across northern Britain as per forecast above, this activity clearing by afternoon. GFS and ECM forecast a highly unstable hot and humid airmass in place across much of England and Wales on Wednesday afternoon, with CAPE values in the order of 1000-2500 j/kg. Again, there is uncertainty whether the strong cap created by upper high across the south and EML (Elevated Mixed Layer) aloft will weaken, however with temperatures reaching 33C inland across central England, weakening heights and strengthening divergent winds aloft, along with weak surface trough moving east across central and northern UK creating convergence coupled with orographic lift, there may be sufficient forcing to break the cap to allow a few thunderstorms to develop across the southern Pennines, Midlands and parts of E England. Strengthening 500mb SWly flow aloft reaching 40-50 knots along with 30-40 knots of effective 0-6km shear suggests any storms that develop will quickly organise … with scope for a supercell or two … capable of producing large hail (1-2 inches), damaging wind gusts, flash flooding and frequent cloud-to-ground lightning. Also, likely discrete nature of storms and forecast strong storm-relative helicity may favour the development of tornado. However, given uncertainties of convective initiation in this region and isolated nature if storms do develop, have refrained from issuing more than a SLIGHT risk of severe weather for now, but may upgrade with the DAY 1 outlook update, if initiation looks more probable and widespread in one area. ... WALES and SW ENGLAND ... Later in the night until end of forecast at 06z Thurs, models indicate another round of thunderstorms, mostly elevated, forming along developing cold front shown on fax charts across Wales and SW England. These storms may bring a risk of torrential rain leading to flash-flooding.

And there was me thinking it was a extra large prison.....

When all the cape goes to pot and only France gets storms

I think in Boston in Lincolnshire it is a case of premature electrification lol

Extended range modelling going for lowish heights over the polar field and flatish type mid latitude type pattern as we tip into a more tropically influenced period and away from the polar influence of the spring. This from GEFS day 15 would be a fair summary of the modelling.. I suspect that once this gets closer to higher resolution, the trough to our west and continental ridge will get picked up better. Currently no real model support for a reboot of the heat days 10 - 15, but I would be hedging towards further heat towards day 15.

Sticky af here on the southcoast Yet there's not a single drop of rain in store any time soon, let alone a storm. Never mind there's always next time. And the time after that And the time after that And the time after that And the time after that And the time after that And the time after that And the time after that And the time after that And the time after that etc.... Maybe by 2050 we'll get a good storm.

Tomorrow is the pinnacle of this current hot spell down south and a record breaking day..34c 93f is hotly tipped and also the fifth consecutive day of 30c + in the south equalling 1995..whatever happens in the remainder of June this month will be memorable for its very summery weather..by me at least!

I've noticed they're always very hesitant to forecast storms. I guess they're so hard to predict where and when they're going to pop up, that they don't bother forecasting them much at all for fear of being incorrect.

UKMO shows a ridge sneaking in at T144. The writing off of the next 2 weeks is way too premature imo, the unsettled weather is very likely up until Sunday then after that it's far more uncertain. I do think it's more likely to be unsettled than not but to outright say guaranteed unsettled for the next 2 weeks is wrong.

Some much larger cumulus developing now!

Latest BBC forecast says gusty winds, torrential rain and hefty hail for tomorrow night quite widely

Going to be interesting following this. It does feel as if the ARGEPE has a bit of a love-in for the Bristol area, but to be fair, yesterday it forecast 33C in that area and it nearly got it right, with 31C/32C officially being reached all through that part of the Severn valley, and 31C even on the N Devon coast which I think ARGEPE was the only one that got close with. So even if it falls 2C short tomorrow, that's still an incredible 35C. Some other forecasts for comparison EURO4: this was 3C too low on the same chart yesterday, so suggests 34C/35C could be reached AROME: 34C in the SE but not as hot in the SW GFS: This model was 5C too low yesterday (apart from in Dorset/Somerset/Wiltshire where it was 2C too low). Again, applying the same correction, it is suggestive of 34/35C, since the darker colour is 30C So general consensus is 34C-35C for Wednesday. Not far off that June record at all. Thursday not a done deal according to the ARGEPE either. 36C in Great Yarmouth??

Tomorrow is still going to be recording breaking according to arpege with 37c/98f on the way easily beating the 1976 record

In the meantime, high summer goes on..bliss

Continuing hot in the south for the next couple of days as everyone knows before cooler weather is introduced on Thursday Just briefly as there is a possibility that this may be covered in depth later by others. According to the METO 31-32C in parts today with tomorrow being the warmest with 33-34C quite likely in a number of areas. Possible some convective activity in the SW today. Further north, NI and Scotland much cooler, in the low 20sC with some cloud. Thursday sees a cold front traversing the country with much cooler air behind which basically heralds the start of a much more unsettled period with troughs from the Atlantic taking closer order. Thus by 12z saturday we see the upper trough tracking east north of Scotland and a showery westerly regime over the UK with temps down to the seasonal average and even below in Scotland. This is quickly followed by the next trough approaching from the west which deepens on the strong jet running east over the UK and by 12z Tuesday is 976mb NW of Ireland and introducing some wet and windy conditions for most. Need, as always, to see what the ecm makes of this.

If June stays at 16.0 or above, it will be interesting to see to see how December turns out. Only two Junes with CETs of 16 or above have been followed by Decembers above 5C There are a lot of such Junes followed by cold Decembers

I am hoping something similar to 9th June 2014 happens on Thursday as I am staying directly under the path that huge supercell took

I reckon Heathrow could be the hottest spot this afternoon at 32c and tomorrow too when a wonderful 34c 93f is realistic..superb spell, loving the current model output for the next few days and hopefully we will see several more spells like this before the end of August and including the first half of September potentially!

ARPEGE must really like the Bristol area! It's been hammering home mid thirties there for the last couple of days. I will tip my hat if it is anything close to 36/37c...that's in the realms of all time UK records! Would certainly be in the top 10 yearly hottest recorded days (with thanks to Trevor Harley): 2003 38.5 Brogdale, near Faversham (Kent) 1990 37.1 Cheltenham 3 Aug 2015 36.7 Heathrow 1 July 1911 36.7 Raunds, Canterbury 9 August 2006 36.5 Wisley (Surrey) 19 July 1932 36.1 London (several sites, inc. Camden), Tottenham, Halstead 19 August 1976 35.9 Cheltenham 3 July

I might be the only one to have guessed too high!

Patience today! It's going to go, and it's going to go big.....!