Man With Beard

At last, an op run following the potential for a pattern change with the Azores High taking advantage of a lull in the Atlantica and bringing in full on summer. Well, now we just have to wait a few runs to see where the future sits between this run and the GFS (General clue ... the answer is usually somewhere between the two!)

There's an opportunity in the next two weeks for summer to turn itself around. It's clear to me that the Azores High is trying to push north - it will bit by bit nudge the pattern slightly north over the next week, and the result looks like a possible hot weekend for the 15th/16th July. But if this nudging of the pattern continues in the week after, we may end up with an extended hot spell for the final third of July. Any let-up in the Atlantic train and I'd say this is a given. The GEFS were keen on this yesterday and this morning, but the 12Z found a little more oomph in the Atlantic and therefore a continuation of the current pattern. Let's hope the Azores High can make this breakthrough while it still has the appetite!

Absolutely right to highlight that Matthew - there's a bigger and bigger chance growing of a window of summer by the end of next week. All day, the GEFS members have been pushing a decent ridge for the UK between T200 and T250. Currently, at least 15 out of the 21 members are high pressure dominated by 16th July (cut that to 12 for the north)

Thanks J10 Well getting into the top 3 of the CET chase is definitely the pinnacle of my amateur weather-forecasting career!! I shall make the most of the moment before I sink back into the pack... Gutted though to miss out getting the June spot on by 0.01, which would have taken me top! (CET was 15.24C, my guess was 15.3C)

Just looked at the extended GEFS. Really wish I hadn't: The depth of that mean trough to our north indicates, correctly, that the vast majority of ensemble members go the same way. The July CET is going to suffer badly if that comes off, and indeed some of the ensembles wouldn't be out of place in November. I said last night that there was a 50/50 split between this scenario and a split trough one (much better for us) and unfortunately this morning the worse scenario has been picked. Not good at all! The ECM mean goes down the same path but gets enough heights into Scandi to prevent the coldest air getting south: Fortunately, there has been a marked pick-up for the coming weekend, not the first time this summer that the models have cancelled Armageddon at the last minute! compared with this a few days ago: that's three or four times since the start of June that the models have backtracked significantly on unsettled weather - something to hold onto as this mid-July nightmare approaches...

The GEFS 12Z follows on from the 06Z (as Frosty picked up nicely earlier) in producing some very encouraging runs for mid-month. There seems to be a clear opportunity for hotter weather coming up after D10. It seems highly likely there will be a deep trough to our W or NW. The key is whether this trough links up with another trough to the E. Those that do not link up allow heat to rise up from the south as with the following charts: The remaining charts see a stronger Scandi trough gobbling up any troughs from the Atlantic, keeping us rather cooler: It's about a 50/50 split between these two scenarios. But there is hope on the charts that ensemble means disguise. We can be buoyed by this coming week, which at one point looked a write-off but to be quite honest is now looking like a very reasonable summer's week in the southern half of the UK at least.

Looking a little better for next week now. All models seem agreed on a weak ridge for the the middle of the week, strongest of all on the ECM. Given the time of year, I imagine mid twenties will be possible at some point (more widely low twenties). Further on, still some depressions getting close to the country but signs on the ECM of them moving in more of a SW - NE trajectory and passing to the NW, which would increase the draw of warmer air. The GFS looks keener to lift the jet a little north more generally. So potential for morr sustained improvements by mid-month, though it must be stressed that troughing remains favourite for being the main influence on our weather, for now at least.

This is not good though ... deep trough setting up to the east, that's going to make it even harder for the hot stuff to get here:

It's the kind of set-up where that's what we're going to have to settle for. Short windows of warmth between Atlantic interruptions. Certainly looks that way until mid-July. Not terrible - but is there a chance we won't record 30C this summer?

So where are we this morning - well, I can't disagree with most posters above, the prospects are not particularly good for beach weather in the next 10 days, and maybe even up to 15 days. But we are also not in write-off territory either - and it is important to stress that. The pressure pattern is such that openings for the Azores high are available in the D8-D12. Pressure remains strong over southern Europe. Main troughing stays essentially to our north. The Atlantic train is not the keenest I've ever. The following ensemble member, fairly typical of current output, demonstrates this picture: There's clearly a possibility that a ridge could sneak in to the UK. The jet is not so ferocious to make it impossible. There are lows in the Atlantic, but they aren't spitting at us on most GEFS members. And there aren't significantly low heights to the NE or E to hinder a ridge pushing in. It's for these reasons that the ECM op is consistently trying to throw a ridge towards us between D8 and D10. On the GEFS, I'd say 7 members are not too bad by D10 for the very same reasons. Don't get me wrong, it ain't great, but neither is it past the point of no return. A very decent weekend for 9/10 July is still a possibility, particularly for the south.

Here's something positive - a few GEFS members now developing something a little better for the end of next week, with a small ridge pushing in. A crumb? Here's one of a few examples

I'll start off with 16.5C. Flat as a pan - no block to the east to stop lows ploughing through, no shape on the jet to allow more than a day or two of warm weather from the south at a time. May change by mid-month but by then it will be too late to swing things far one way or another. So I'm going for average average average ... and if I were betting one way or the other, slightly below.

Into July, the jet stream on the GFS 00Z op is reasonably well replicated on most ens members: http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=3&ech=300 A fairly strong jet, running west to east through the UK. Meaning settled weather will be hard to come by. On the same token, the jet will probably keep out a direct northerly flow too. So probably average conditions for the first half of July, or slightly below average if there turns out to be a prolonged train of depressions. SE areas most likely to do a little better.

Well an uncertain week from the models last week has led to a very uncertain forecast for this week - hot weather close to getting in (and could do so on Thursday) but never settled, and you couldn't rule out a soaking at anytime. Further ahead, the UK sandwich looks likely - heights to the west and east and troughing drawn like a magnet to the UK - glimmers of hope from UKMO and GEM that heights may build sufficiently over the top but we'll be needing to see much more of that in the models - an eventual NWly mean flow looks favourite for next week right now

Can anyone remember the last time we had model agreement at D6?? Seems a long time ago. Early next week finally coming together - the GFS, completely alone at points this week, seems to have picked the pattern well for the start of the week - rain Monday, clearing up Tuesday. Most models then give us a couple of warm days (away from the north). Then the divergence is back for the end of the week. ECM still looking at a thundery breakdown, but GFS this morning cuts the tough off to our SW, leading to a heatwave. The GFS is way out of kilter even with its own ensembles, but this week has proved once again, never discount it!

ECM/UKMO runs woud put us at above 16C by the end of next week, surely? Much warmer than GFS, and at a very short time away

CS you beat me to it!! So instead I'll pin up the very pleasant 850s for next week. They also demonstrate nicely how the Atlantic trough has completely stalled - see the 8C 850s line getting absolutely nowhere... And here comes the plume at T192 - 20C hpa into the Bay of Biscay - might just be a little too tardy to get to us?

Latest ensembles give last week of the month averaging around 10C in the 850s category - above average - so I'd imagine the final CET might be between 15.5C and 16C (before corrections). Very warm! Thanks BFTV for the stats, by the way

A mild change on the ECM ensemble mean this morning: yesterday's 12Z and 00Z means: The trough to the west is getting progressively more pronounced and the added heights to the NE makes it stall sooner. The result is the potential for an easterly influence for a couple of days, before the trough probably gets over us later in the week. Taking the models as a whole, the ECM is ever so slightly out, though it is the king of the splitting trough at around T120/T144 so it must be given extra attention. The GFS and UKMO both push the pattern through much quicker (4 or 5 GEFS members give support to the ECM but most don't). However, the ECM has an ally in the GEM this morning: which is a return to the peachy runs of a couple of days ago. It does look, though, that slow moving low pressures may be close by come D9/D10, trapped between the Azores High and the Scandi High, as Damianslaw pointed out last night. So putting the GEM to one side, it doesn't look like it will ever be settled for too long next week, but the kind of unsettled pattern could still be a warm/thundery one, with potential for any spots which can avoid onshore breezes, convergence zones and frontal areas to have a corker of a week. If the ECM comes off, maybe the NW and Wales again? If the GFS/UKMO, the SE might be good aside a weak front or two.

If anything, I think the mid-term outlook has got more uncertain today rather than less. Both GFS and ECM ops at T168 see a trough splitting just before arrival to the UK. This makes me think the idea of a splitting trough is now a clear favourite. However, anyone who has studied splitting troughs in summertime knows that you cannot pin them down until T72 - ECM sometimes picks them correctly at T120. If it splits early enough, it could sink towards Biscay, leading to a possible plume, maybe even a return to the ridge dominated runs we saw yesterday. Or it may stall over the UK leading to a very wet few days.

Mean chart yes, clusters no. The mean is being flattened because of the mix of HP dominance, a few stalling troughs (with timing influences on the mean as they approach the UK) and a few that still keep the trough a little stronger. But virtually no charts on the GEFS tonight actually replicate the mean. On to the ECM T216/T240, this morning I said I was looking out for a cut-off low that would lock in a heatwave - well the ECM very nearly goes and does it - any further south with the trough and we're in 1976 land - as it is, the ECM kind of snatches a slight defeat from the jaws of victory but it could still be hot for many all of next week if ti verified.

Not huge. The op run is indeed the best run, but at least 10 other ensemble members are settled and warm/very warm during most of next week. Not many have troughs anywhere near the UK by T240: so more like the 00Z ensemble set than the 06Z (which was much more changeable) ECM looking very good by T168 - I'd expect a split trough to follow by T216 and the possibility of a plume - like so many other runs we've seen today across the ensemble range. Edit: ECM T192 - beautiful angle on the left flank of the high to bring up something very hot for T216 / T240

The last 4 GEFS runs combined suggest not particularly low heights towards the end of June. 850s average close to 9C for London too. That's warm for the end of June. http://www.meteociel.fr/cartes_obs/gens_display.php?x=306&y=141&run=100&ville=Londres&runpara=0&type=0&ext=1

The GEFS 06Z swings more unsettled A much stronger Atlantic trough on most members. Not many hot runs this time.

This morning's GFS isn't quite up to yesterday's 12Z (which was nearly perfection for summer lovers). But you don't have to go far to find some even better runs - and worse too. This mornings 00Z GEFS for D8-D12 shows a split in the clusters, but I'd say still a favouring warm, predominately dry but perhaps thundery outlook. By T240, just 6 members could be called changeable or unsettled, like this one: About 5 members would result in at least a short heatwave. like this one: The remaining 11 members at T240 are also predominately warm or hot and sunny, but they have a minor sinking trough separating two areas of heights. In general, the trough is more a thundery interruption than a breakdown. The trough brings the possibility of a plume ahead of it; here's one of a few examples- doesn't quite make it but close: This latter idea of two areas of heights separated by a minor trough can be seen on the ECM mean for T240, and the ECM op run isn't too far off but with a better developed trough So things beginning to become clearer for the next 10 days - unsettled this week, clearing up at the weekend, at least a short warm/settled spell for most to start the following week (maybe NW areas most at risk of missing out). Then, from mid-week onwards (D9-D12), a few options, but many of them this morning point to something warm and occasionally hot in the SE, possible breakdown but that's by no means the smart option at this moment. Bearing in mind the way June had gone so far, with models progressively holding the Atlantic back as T0 approaches, I remain confident that the final third of June will be very good indeed. In the next few runs, I will be looking out for heights building over the top of a sinking trough over Biscay - that could lock in a heatwave.