Model Output Discussion 18z 28/07/13

[Summer Sun]

Sensational ECM with high pressure dominating and becoming increasingly warmer maybe even hot at times in the south

 

http://www.null/ds/ecm.htm

 

[J10]

Stunning ECM tonight for those wanting dry warm and sunny weather over the bank holiday wekend.

 

Maybe not as hot as GFS, but much better IMO.

Edited August 17, 2013 by J10

[Frosty.]

Tonight's Ecm 12z is incredible, i'm not sure what I expected but this is the BEST possible outcome for longer term prospects, this anticyclone shown here would be hard to budge and the temperatures just keep going up and up, it would be a nationwide heatwave in the making with not a sniff of a cool breakdown, the bank holiday weekend would be sensational, hot and sunny and the following week would also be hot and sunny, yes it's EPIC and we should definately BANK it... 

[Bonjangle]

Tonight's Ecm 12z is incredible, i'm not sure what I expected but this is the BEST possible outcome for longer term prospects, this anticyclone shown here would be hard to budge and the temperatures just keep going up and up, it would be a nationwide heatwave in the making with not a sniff of a cool breakdown, the bank holiday weekend would be sensational, hot and sunny and the following week would also be hot and sunny, yes it's EPIC and we should definately BANK it... 

COSTA-DEL-SOL-UK  

Edited August 17, 2013 by Bonjangle

[Methuselah]

Tonight's Ecm 12z is incredible, i'm not sure what I expected but this is the BEST possible outcome for longer term prospects, this anticyclone shown here would be hard to budge and the temperatures just keep going up and up, it would be a nationwide heatwave in the making with not a sniff of a cool breakdown, the bank holiday weekend would be sensational, hot and sunny and the following week would also be hot and sunny, yes it's EPIC and we should definately BANK it... 

Don't you go getting yourself carried away now, Frosty! 

[summer blizzard]

GFS for the third day sticks to the trend to attempt to build heights over Greenland into FI. Unfortunately while it gets there tonight, the supporting low appears to find a weakness in the ridge which flattens the pattern,

 

 

 

[Bonjangle]

 http://www.express.co.uk/news/uk/422687/88F-Heatwave-to-blast-back-and-last-until-September

[Scorcher]

GFS for the third day sticks to the trend to attempt to build heights over Greenland into FI. Unfortunately while it gets there tonight, the supporting low appears to find a weakness in the ridge which flattens the pattern,

 

 

 

 

'Unfortunately'? I reckon you might be in the minority in being upset about this tonight! Sorry but a Greenland High just doesn't look likely at all to me, it's been conspicuous by its absence this summer thank goodness!

[J10]

'Unfortunately'? I reckon you might be in the minority in being upset about this tonight! Sorry but a Greenland High just doesn't look likely at all to me, it's been conspicuous by its absence this summer thank goodness!

 

Happy for it to come back though into the late autumn though.

[Methuselah]

Happy for it to come back though into the late autumn though.

Aye. Mid December would be a good time!

[damianslaw]

All models are showing an increasingly settled warming spell for all, as once again the azores high is forecast to nudge a ridge NE into southern parts and the jet transferring northwards - not a pattern we tend to see very often in late August....

 

The prospects for August bank holiday look very good if you are after very warm/locally hot conditions. At this stage it is too early to call whether such warmth is going to be accompanied by clear blue sky type conditions, or milky white skies with the threat of thundery downpours always in the air..

 

The odds of sustained sunny blue sky conditions wane rapidly as we approach late August this is not late spring/early summer. Keep an eye on developments to our SW, a thundery trough could very likely pop out of nowhere and spoil the party... there is a much finer balance to our weather in late August between fine settled weather - and unsettled conditions compared to earlier on in the summer.

 

All I'm saying is at this time of year the odds of a sustained summer spell of weather are much lower than in the late May-late July period.

[Bristawl Si]

I could've sworn some people on here were saying Summer was over only a week ago.

Stick to the day jobs guys.

[Costa Del Fal]

18Z GFS good up to Friday/Saturday then a trough gets stuck over us before renewed HP in FI. Does seem a rather progressive run however and doubt such changes will be so quick. Not saying that because I want the heat/warmth to last longer but to me it does seem a little against the overall trend at present, but who knows, others may fall in line.

[bluearmy]

where is the trough going post day 6? How strong a feature will it be? Wlll another ridge build back over as per early august? Those who coninue to promise much baed on operationals post day 6 are always asking to be dissappointed. The overall picture maybe a fairly settled one but even a weak trough can upset a 24/36 hour period which, given that we are talking bh weekend, could bust a forecast very easily from an emmotional perspective of those listening.

[Man With Beard]

Going to need a bit of luck next wkend, whether you like it sunny or thundery. All models place the shortwave over us, but seeing it's quite small it could easily miss us too. Could be some local variations.

[mushymanrob]

I could've sworn some people on here were saying Summer was over only a week ago.

Stick to the day jobs guys.

 

.... and with good reason... how often has a 'hot' spell evolved at the end of august after 3 weeks of atlantic driven weather?( and im not talking about 'nice' or 'pleasant' days, im talking about a protracted hot spell like the one currently expected)... the chances of this occurring were very much against it happening, so betting against it was a fair bet. fortunately, im happy, happier then most here, to be wrong, and we do look like getting something hot

 

hmm.... cloud could be an issue later in the week, as these fax sows embedded upper air decaying fronts

 

 

theres another cloud in the ointment for next weekend, a thundery low? or something more seasonal (gfs) which could end up spoiling the whole event?

 

either way this mornings ecm is a cracker (didnt see the 12z) and if im right , has the support of the anomaly charts... which have been consistent with very similar runs although no total agreement.

 

so it might not be clear blue skies and sunshine with increasing temps all the way... but this week should be gradually warmer, drier and calmer until a thundery blip next weekend, by which time itll be humid. beyone next weekend is looking very much like high pressure will prevail, either over us or to our north.... what a great outlook, that goes some way to compensate us for that dreadful spring! :lol:

Edited August 18, 2013 by mushymanrob

[shedhead]

where is the trough going post day 6? How strong a feature will it be? Wlll another ridge build back over as per early august? Those who coninue to promise much baed on operationals post day 6 are always asking to be dissappointed. The overall picture maybe a fairly settled one but even a weak trough can upset a 24/36 hour period which, given that we are talking bh weekend, could bust a forecast very easily from an emmotional perspective of those listening.

Indeed bluearmy, recent runs and particularly the 00's have made some recent posts look rather silly, even a little cringworthy. Ignoring the LP running into the west midweek was always fraught with danger, as was assuming if it did materialise a quick and strong build of presssure behind it is/was an absolute given.

 

What we see this morning is a pretty average week for the north, with temps starting a little below average and finishing a little above.

 

The south still looks in line for a mostly dry and increasingly warm working week, but even here I would not expect wall to wall sunshine, especially the farther north and west you travel. By the weekend (perhaps not unsuprisingly as it's a Bank Holiday for most) LP looks set to return, bringing the prospect of some rain or showers and much lower temperatures.

 

Beyond this I'd suggest waiting to see what the models come up with across the next few days before making to many assumptions about prospects for the following week.

 

Been saying this for days now, any signs of a nationwide heatwave or epic hot spell look as far away as ever this morning.

Edited August 18, 2013 by shedhead

[MP-R]

Oh dear. Warm, settled spell looks ever shorter, and uncannily the onset of the trough from the west is timed perfectly with the weekend yet again. That shortwave is proving the party pooper should it evolve as shown by the models. At least however high pressure is shown to make inroads again shortly after.

[bluearmy]

Indeed bluearmy, recent runs and particularly the 00's have made some recent posts look rather silly, even a little cringworthy. Ignoring the LP running into the west midweek was always fraught with danger, as was assuming if it did materialise a quick and strong build of presssure behind it is/was an absolute given.

 

What we see this morning is a pretty average week for the north, with temps starting a little below average and finishing a little above.

 

The south still looks in line for a mostly dry and increasingly warm working week, but even here I would not expect wall to wall sunshine, especially the farther north and west you travel. By the weekend (perhaps not unsuprisingly as it's a Bank Holiday for most) LP looks set to return, bringing the prospect of some rain or showers and much lower temperatures.

 

Beyond this I'd suggest waiting to see what the models come up with across the next few days before making to many assumptions about prospects for the following week.

 

Been saying this for days now, any signs of a nationwide heatwave or epic hot spell look as far away as ever this morning.

 

but thats maybe a 'too pessimistic' outlook shed. cant assume the block will give way without any fight. 

[shedhead]

but thats maybe a 'too pessimistic' outlook shed. cant assume the block will give way without any fight. 

Which bit ba?

[Summer Sun]

Apart from the odd possible blip at times next weekend the outlook is one for high pressure to dominate our weather

 

 

Could be a wet spell especially in the south during the BH weekend but further north high pressure should keep it mainly dry

 

 

ECM ends its run with high pressure keeping most of the UK dry though the south may be more prone to rain at times.

 

 

With low pressure firmly in charge across Greenland I can't see any quick return to low pressure over the UK at the moment thankfully

 

[J10]

Some posts in here this morning could look rather silly come this evening to be honest.

 

The GFS not the best this morning but the op run very much at the low end of pressure ensembles. with the average close to that of the op ECM.

 

 

The ECM still not that bad, and the "shortwave" largely missing us to the south.

[Methuselah]

Aye J10: clear indications of some dry, warm and reasonably sunny weather ahead...Of course summer will eventually be 'over'. But, as of now, it's clearly on hold... 

[Tamara]

Indeed bluearmy, recent runs and particularly the 00's have made some recent posts look rather silly, even a little cringworthy. Ignoring the LP running into the west midweek was always fraught with danger, as was assuming if it did materialise a quick and strong build of presssure behind it is/was an absolute given.

 

What we see this morning is a pretty average week for the north, with temps starting a little below average and finishing a little above.

 

The south still looks in line for a mostly dry and increasingly warm working week, but even here I would not expect wall to wall sunshine, especially the farther north and west you travel. By the weekend (perhaps not unsuprisingly as it's a Bank Holiday for most) LP looks set to return, bringing the prospect of some rain or showers and much lower temperatures.

 

Beyond this I'd suggest waiting to see what the models come up with across the next few days before making to many assumptions about prospects for the following week.

 

Been saying this for days now, any signs of a nationwide heatwave or epic hot spell look as far away as ever this morning.

I too agree with the thrust of bluearmy's post - however I am less convinced by your own reply and interpretations of things

 

So often the glass is either overflowing in this thread or it has a hole in the bottom of it

 

A sanguine view of things might be that there was always good support and confidence that the mid-week shortwave would not prevent a pressure build either in advance of it (as is starting to happen as I type), behind it (from mid-week itself), or even on top of it in the case that the residual trough split the presently building High pressure cell and the one it merges with after midweek. The gist of this was explained yesterday morning and nothing has changed in that respect since then and won't change from now on either

 

So, taking these facts into account, your comment about the mid week low being 'fraught with danger' is perhaps rather overstated in terms of the general pattern, and evolvement of that - beyond the nuisance value it was always likely to bring to more north western areas of course

 

In terms of the B/H weekend, well again as suggested yesterday, there is the growing possibility of the Iberian trough moving north eastwards as the more progressive solution to bring at least a temporary interruption to the fine weather. The uncertainty of this was also mooted by the METO yesterday..but then it is a B/H weekend and extra caution is always going to be applied in this sense.

 

However, what will be interesting to see are the updated EPS charts for next weekend - because the 12z set from the ECM was largely less progressive than the ECM operational this morning which has reflected rather more what the GFS started to suggest yesterday.  Models are often over keen to try to remove High presure systems in these scenarios and whilst a trough to the south west is pretty well assured, its movement and extent northwards and eastwards cannot be trusted at this range - especially with the prevalence of mid latitude ridges not looking like going very far for the foreseeable future. Again much as suggested yesterday.

 

I think much of this has been echoed by most others too as the likely way ahead, and whilst posts have been made with descriptions of what various models show, in terms of possible very high temperatures, this is not the same as suggesting to people that they are necessarily going to happen. I guess this is not the first time this point has been made and probably won't be the last either

 

Notwithstanding the uncertainty of next weekend and the possibility of an interruption to the late summer spell in terms of some thundery showers perhaps, I think it is also an overstatement to suggest that much lower temperatures seem likely. A drop in temperatures relative to the possible high temperatures at the end of the week is conceivable - but they look to remain the warm side of average for the foreseeable future and never the cool side of average anywhere. At the least. Much as the updated ECM ensemble mean for the B/H weekend itself suggests

 

 

Whilst typing this, the EPS members have also updated and suggest more of a mixture of solutions for next weekend. Some have the trough close by, some retain the ridging still as suggested more widely last night, and some are rather indeterminate. A straightforward High pressure solution is less likely, but I think no-one should place any bets as to any particular specific outcome.

 

What does seem reliable enough, is that temperatures are not going to be an issue next weekend - come rain or shine

Edited August 18, 2013 by Tamara Road

[johnholmes]

What the pair of charts from ECMWF-GFS show in the mushy post is an upper low very close to the UK along with +ve height anomalies. The charts shown are valid for end date 29 August which is Thursday, several days after the BH weekend. They do not look especially settled but one does need to keep some perspective if it is the BH weekend worrying you and trying to use the anomaly charts.

The pair of charts for Monday 26 August show the mentioned trough/cut off upper low beginning to edge quite close, still with the +ve height anomalies showing over much of the country.

I suspect the synoptic models will struggle through much of this week as they try to work out, given that the anomaly charts will probably prove to be about right, just what both the 500mb and surface situation may be. Best to take an overall view and average out the swings and roundabouts that will show over the next few days. The rainfall over the weekend and the model predictions of when/where/how much should serve warning on trying to read too much into moisture detail more than 24 hours ahead. Temperatures should be sorted rather more quickly.

Certainly an interesting few days of model watching as folk understandably hope for a good final BH weekend in terms of weather.

Edited August 18, 2013 by johnholmes