Man With Beard

The Icelandic ECM charts now appear to show next Wednesday as being hot pretty much nationwide, with just the SW, Wales and N Ireland under the influence of encroaching fronts by then. Still, things will change further

I think that is a factor when trying to keep the hottest weather over the UK - in July we could pretty much sustain it but now we need a constant continuation of the hot feed - which is why a slight change in flow in charts between Monday and now mean we're looking at uppers of 16/17C rather than 20/21C. Still the charts remain hot for Tuesday and increasingly Wednesday across all charts - once again, models seem to have been overestimating the ability of the Atlantic against a block directly to the east - so perhaps 30C on Tuesday around Bristol, and 30C on Wednesday in London, I'm guessing - if these charts were to verify. But do I now suspect a trend to keep it very warm across especially eastern parts for the entire week? The cooler air of the Atlantic failing to make much impression on upper air by Thursday. Of course, a change in the charts earlier lead to changes later, and the failure of the Atlantic to get through encourages more high pressure to approach to uk from the SW by the end of the weekend. The GEFS is full of high-pressure dominated charts by T240 - though worth mentally knocking off 300 miles to the northern extent of the highs to be on the safe side!

The latest installment for Wednesday: A lot of warmth still around then You can see that the GEFS still has some runs reaching the magic 20C 850s mark over the UK - the op, believe it or not, is actually on the cooler side - these are the ensembles for E Sussex The precip chart for GFS shows that front trying to cross the country - anything ahead of it will be hot (maxes close to 30C in favoured spots if the front doesn't make it). The best precip chart I have for ECM is Wednesday 00am - hard to see but looks like the rain is well back It's going to be a T24 job working out what will happen with that, we've situations like these at T144 where the front doesn't even make the SW by T0, or where the front has cleared the east coast. Now onto the thundery stuff - actually Tuesday evening looks the tastiest on GFS, but Wednesday also has a chance. I suspect other outputs may differ

Stalling, stalling, stalling ... the Atlantic is making even slower progress on tonight's 12Zs so far. The Scandi High is looking stronger on all runs by Wednesday, which now more realistically could be hot away from the south west, as many of these runs do not clear the warm away by then. The GEM is hotter for Monday too.

Snow princess - just saw your post, sorry I'm going to be straight up I really don't have a clue what the weather will be like next weekend, I feel that the UK is stuck between two areas of settled weather and it's a lottery right now whether we will join in or not! I doubt it will be hot though. Perhaps if you give details of your journey some others might chip in!

Fair enough Karl. It seems this summer and last the GFS slightly overdoes the northwards push of heights from Azores

Looking at the GEFS 06Z clustering, the message is - Hot Tuesday (maybe not quite as hot as previously forecasted in the days before but still will feel hot in any sun), still a couple of runs getting the 20C 850 line over us so 90F remains a possibility, though might just fall short. - Wednesday still in the balance, depending on the northward progress of the Atlantic front (v. warm/sunny ahead, wet in the middle, sunny but a bit cooler behind) - By the weekend, the signal gets lost completely for the UK. We have heights in N Scandinavia and heights of course in S Europe and the Azores. Some runs join them up, leaving us dry but temperatures varying massively depending on the link-up. Other runs push a trough through the gap, leaving us cool, cloudy and damp. Looking at the whole set, I personally favour low pressure escaping east Thursday/Friday and pressure building again from both the south and the north - leaving us in a dry, light NEly which would make the SW the warmest spot, possibly mid-20s if that happened. At least that permanent trough to the north might be obliterated this week!

This really does depend on ones opinion of cool. I was sitting outside on Hayling Island yesterday in 21C, and to me it was comfortable when cloudy, and roasting when sunny! I would expect midland areas to experience these type of conditions at the weekend, and south of Bristol/Oxford/The Wash I'd expect those GFS charts to translate to 25C or 26C in places, maybe cool to some but I doubt cool to most. ECM 00Z ups the heat a little for next week compared with its 12Z yesterday. 16C uppers comfortably getting over the country by the end of Tuesday, up to 18C overnight and perhaps some warm air hanging on long enough for a warm Wednesday in the east. Will be interesting to see how thundery potential develops

A more sedate morning on the models so far. The GFS op has edged the heat down a little over the past couple of days - probably just the Tuesday which will exceed the 30C mark now (so still very hot), and little interest in a split trough so a more straightforward breakdown on the Wednesday. GEFS generally supportive of this, except that a number of runs still get the 20C 850 line to the UK at some point.

A little worried after seeing the latest ECM!!! But I agree with CS's logic, I still think the max on Tuesday will have a 3 at the beginning. So if anyone wants to see me strip, you'll have to go to Southsea Beach... And here we go with the trough disruption chaos! Expect to see many solutions coming up for the Wednesday to Saturday period next week! Tonight's ECM eventually parks a low over S England and northern parts get a decent Thursday/Friday too, as heights to the north back west! In fact they do so well backing west, we end up with a coolish NEly. The first major Atlantic fail on an op run in this period, but I doubt it will be the last.

I completely agree with you - in all honesty, the charts have been pretty consistent for a slightly extreme situation. Still hot Tuesday with 90F in sight on GFS (not record breaking but the only way is down from perfect!), and maybe hot on Wednesday. But the fun really starts on Wednesday. The UKMO often trumps the other models with the SW low coming up against heights to the east - and look at Tuesday, it's already got a blown up trough way to the SW. Could it slide underneath us?? I'm now wondering if northern areas will get a better second half of the week than they expect. It's all developing nicely! Also, some people saying this is not a plume? It certainly still is. A straight line run of heat moving up from Spain. We've been a bit spoilt by super plumes last month and July 2015, but it certainly is a plume.

GFS 06Z is less hot. Perhaps 31C would be the tops here

Genuine question Nick, the Icelandic charts appear to show cloudless skies (chart is for Tuesday early morning), is there something missing here?

I won't go off topic anymore than this, but just to say, honestly, I wouldn't hope so, it's not a pretty sight.

Nick, I know you're only posting what you see so I'm sure you will understand this is not a dig at you ... but I will post a naked photo of myself on this thread if this mornings ECM op chart for next Tuesday verifies (with its pressure, cloud cover, 850s and rainfall forecast as it is) and 30C is not exceeded. My reasoning - uppers forecast to be between 16C and 17C by midday Tuesday - in a continental airflow within minimum sea track, fairly light winds, probably clear blue skies, not a monumental increase in heat from previous day, dry ground conditions for the previous week - in August that should translate to a near optimum transition between upper air temps and lower air temps, so between 14C and 17C higher than upper air temperatures depending on local conditions (e.g. exposure to sea air, height above sea level, shelter from wind direction e.g. Cheltenham is sheltered by the Cotswolds in a SE wind) - therefore a maximum should be 30C at very least (16C uppers + 14C) and maybe just maybe 34C (17C uppers + 17). We reached 28C this past Sunday on charts nothing like these!

Good to have you back Knocker. Well this morning's ECM sees trough disruption throwing a spanner into modelling. A mini-low appears over SW England, splitting in between heights to the north and south. Now normally this would just be a case of who gets the rain - SW, central, east or north - the type of situation where those forecasted to be wet at T48 might end up dry by T0, and vice versa. But when this much heat is around - - there is the potential for some incredible contrasts in weather that may not be fully forecast-able until very very near T0. The difference in modelling between 22C and 32C will be very small. I think we're pretty well set now until Tuesday. But Wednesday onwards may end up a forecasters nightmare if the tendency to split a trough near our SW continues. Coldcomfort - I wouldn't be so pessimistic - I think Manchester will get lows 20s over the weekend (Saturday a little dodgy but might be ok) and high 20s are possible any day from Monday to Wednesday, even Thursday if that low is a little further south. You'd settle for that wouldn't you?

And the 00z carries in the same way, potential for a tasty thundery breakdown too, perhaps. Interestingly, slightly more progression is actually helping the heat stick around as a slightly more progressive trough to the NW prevents heights escaping north so quickly (not the case on UKMO). Well supported by GEFS. Of course the heat gets going much sooner for southern areas - 27C a likely maximum mark from Friday onwards - charts are similar to last weekend's and that's the values we got. The heat goes nationwide by Monday, 29C ish a possibility somewhere. Tuesday 32-33C, a perfect hit could bring 35C. Wednesday might touch 30C-32C again before the breakdown sets in.

ECM ensembles, like GEFS, much hotter for the Wednesday. 14C at 850s for the SE, 12C for many - spreads indicate there will still be a fair number of hotter runs too. So a good 4C warmer than the op run, potentially. Probably not lasting to Thursday but still early days.

The ECM op finishes, like the GFS op, in a pretty ordinary way, with the 90F plus heat gone by Wednesday daybreak. Are the ops leading the way? Possibly. But having said that, they've gone from being the hottest runs on their ensembles to perhaps now the coolest. The journey continues towards the truth...

ECM for Tuesday - now at T168 - this day has been consistently a scorcher on the models and no change tonight - a max somewhere between 32C and 35C on this I'd think

The GFS is colder on Wednesday next week than any of the ensembles (looking at surface temps) - about half keep it hot. Lots of fascinating possibilities for D8-D11

I don't see any reason why P1 couldn't happen. It's not an outlier earlier in the run. It's all about timing. P1 is only very slightly different to the mean because, by T162, it does not develop a negative tilt between Iceland and Scotland on its leading edge, which means the first disturbance on the south flank of the main trough does not disrupt SE, but instead carries on around the low. Some heights get in between this disturbance and the second disturbance - and consequently, the second does disrupt SE. The heat is then caught between the two disturbances. It requires optimum timing, but it isn't ridiculous. 2 other ensemble members do exactly the same, just not quite as hot. 20% chance IMO.

It is truly sad that I remember this, but P1 was one of the few ensemble members that picked out the July heatwave at distance - oh my goodness, I look at these charts far too much. We're a million miles away from nailing down the breakdown yet. We haven't even mentioned thundery potential?

Yes - that's exactly what I meant - I translated clustering just above 25C equating to maxes around the 30C or a bit more. Steve - you're very level-headed in the summertime!! I trust you'll have your ramping fingers back by Novembrrrr??!!

GEFS ensembles for the 06Z - looking at next Wednesday, this is clearly the most popular cut-off point for the heat, with a pretty even split between the runs that maintain the heat throughout Wednesday for most and those that have already chased the heat away the previous night. The number of ensemble runs that maintain a Scandi High that maintain a continental flow over is UK by the Friday (T240) is just 4. So the idea of keeping the heat going throughout the week not particularly strong on this ensemble set. But so much water to go under the bridge yet. We're probably well set until Monday now - generally fine with increasing warmth apart from a weak front Saturday/Sunday that may not amount to much, Monday/Tuesday very likely to be hot (but how hot??), then Wednesday onwards is the interesting bit where, I still feel, a twist could come if a Scandi High is close enough to the UK. Interestingly, the extended GEFS (T250-T300) maintains some heights to the east, and the trough generally too far to our north-west to cause too much bother, so a half-decent period between D9 and D13 with warmth and sunny spells could transpire, though clustering not really strong enough to provide much confidence there. ECM ensembles for London show strong clustering for heat on Tuesday/Wednesday next week (again, around the 30C mark for maxes more likely than 35C I guess), and then a drop back to normal or slightly above normal for the rest of the week. This is probably a massive amount of over-analysis at such a long way out (fair point AJP!!), but I think it's interesting to follow trends - and I'd say the model trend so far today is to be a little more definite about whatever heat there may be probably being over by Thursday next week - but personally I'm still not so sure because of past experiences of an Atlantic failing to break down blocks to the east at the first attempt!