Model Output Discussion - 1st June 2015 12z--------->

[Tamara]

This weeks hot spell lasting till next weekend is under full discussion

 

Current Global Wind Oscillation orbit through Phase 5 and then into 6 are very well matched in the composites to these phases with latest NWP output up to, and just following the main plume heading into the early part of next week

 

All 8 GWO H500 composites are linked here:

 

http://www.atmos.albany.edu/student/nschiral/research/gwo/composites/JJA/hgt500_1.png

 

These have been lagged out to 10 days to provide the closest match

 

The upper trough in the Atlantic and the downstream ridging clearly advertised in both Phase 5 and 6 composites - the only difference being the very slightly flatter jet profile in Phase 6 with a more tropical maritime SW vector indicated

 

A renewed pressure rise set to occur from the SW then, after the main plume exits at the weekend - meaning more warm/very warm weather to come, although a little more changeable furthest NW closer to the upper trough

 

The NAEFS H500 mean pressure anomalies for days 7/8 are a very good blue print copy of the July GWO composites heading into Phase 6.

 

http://modeles.meteociel.fr/modeles/gens/naefs/run/naefs-0-0-180.png?0

 

The mean height anomalies will obscure surface detail interpretations however, and despite the relatively slightly less amplified profile overall than this week ,clearly the synoptic pattern will not not need much further encouragement to re-advect futher extra heat - more especially towards SE parts of the UK.

 

This is because the upper low will quite likely have further shortwave development around the main trough to the NW - and any slower phasing of these will assist with a little further extra amplification of the highest uppers northwards which will be still residing close by on the continent. This maintains a small risk of thundery incursions to the south of the UK next week at the same time as weather fronts may brush the NW

 

Recent isolated pockets of operational output, mainly over the weekend, suggested (far too prematurely) a hint of cooler rather more changeable weather becoming more extensive over the UK.

 

At face value, any further progression from Phase 6 GWO into higher amplitude Phase 7 (see the above particular composite in the list)  suggests the pattern flattening out more extensively from that in Phase 6, at the same time as some height rises occur ovr Greenland and NE Canada.

 

The Global Wind Oscillation is for sure, I am now convinced, an invaluable forecasting tool - but I would trust forecasts from the GEFS in atmospheric tendency FI hinting at this type of eventual solution as little as any synoptic NWP doing so this far away in time.

 

Evidence in my opinion is increasingly counter intuitive to this.

 

For what it is worth regarding that extended period - it is quite conceivable that what may actually happen is that the GWO orbits at a lower amplitiude Phase 7 back into Phase 0 (as the current active MJO passage towards the dateline fades) and provides a passage of weather not too dissimilar to what we have seen in the last week.

 

Further to that, with strengthening Nino now fully imprinting in atmospheric tendency feeback loops, there is credibility to renewed convection firing across the Pacific and progress eastwards once more. This will re-activate tropical forcing signalling, and the response in these circumstanes will be the GWO orbit emerging back into Phase 4/5 as positive frictional torques are renewed a second time

 

What does this mean in English?  Simply that the pattern re-cycles back to the present, and we see the trough back west once more, sharpen, and pump up another Sceuro ridge.

 

As you were

Edited June 29, 2015 by Tamara

[seaside 60]

Interestingly the latest met office update says it will turn very warm and humid again next week away from the northwest of the BI after a cooler and fresher day on Sunday with an increasing chance of thundery showers in the south by next midweek which sounds to me like plume type weather returning, at least to the south, similar looking even further ahead too.

It doesn't sound to me like we will be seeing a return to the normal / sometimes unseasonably cool pattern which dominated most of June..ie LP to the northwest and HP to the southwest which is what the EC32 showed, the MO further outlook is for a continuation of summery weather apart from the occasional cooler blip..e.g. this coming Sunday.

I dont always agree with you, however this time I do, lol..

The MO must be very confident from their model views.

There is a very clear signal for the south to be much warmer than average for some time, with nearing hot spells and possible thunder.

I am not sure a plume is exactly the type of weather expected, however they seem to be reading the overall situation differently to some on here.

Its the time for Ian to give us those little hot bits of info.

[Frosty.]

I dont always agree with you, however this time I do, lol..

The MO must be very confident from their model views.

There is a very clear signal for the south to be much warmer than average for some time, with nearing hot spells and possible thunder.

I am not sure a plume is exactly the type of weather expected, however they seem to be reading the overall situation differently to some on here.

Its the time for Ian to give us those little hot bits of info.

It would soon become very boring if we all agreed with each other but I have to say, I agree with you on this occasion, lol Edited June 29, 2015 by Frosty.

[Milhouse]

GFS is back showing 30c+ for eastern England with the transition to cooler conditions delayed long enough to produce another hot day

 

[Captain Shortwave]

The GFS is predicting that 32C will be reached on Wednesday, Friday and Saturday on the 12z. That is pretty darn good for a hot spell in the UK usually.

 

Interesting to see that the potential for a very hot Saturday is still hanging on. Whilst only central/southern England will likely see the potential hot/very hot conditions it still looks like the mid to high twenties could be possible anywhere away from windward coasts.

The GEM also brings the 20C isotherm back over the south on Saturday with again 90F possible then and on Friday. The UKMO again looks flatter and more progressive.

Edited June 29, 2015 by Captain shortwave

[William Grimsley]

Nice looking GFS charts on the latest run, hoping that tomorrow night does materialise here but I'm not too optomistic.

[MR EXTREMES]

Indeed Tamara there's certainly a clear trend towards a rinse and repeat pattern.

you can see by the model outputs that the lower heights seem to get stuck in the Atlantic.

Reminds me of the 80s type summers

[seaside 60]

It would soon become very boring if we all agreed with each other but I have to say, I agree with you on this occasion, lol

Which in turn seems to be what Tamara is saying as well.

Talking of boring, I think this weather down here will become boring if it stays to hot.

Maybe the talk of the summer will be model watching for cooler weather, lol...

[Summer Sun]

GFS showing a new are of high pressure building next week which is an improvement on the 06z

 

 

It looks like turning drier away from the northwest where there is the risk of rain, it will be turning warmer again for all after a fresher feel later in the weekend

Edited June 29, 2015 by Summer Sun

[mhielte]

Last two GFS runs have upped the heat for this week, with a stronger return of the plume heading into Saturday

 

[knocker]

Indeed Tamara there's certainly a clear trend towards a rinse and repeat pattern.

you can see by the model outputs that the lower heights seem to get stuck in the Atlantic.

Reminds me of the 80s type summers

 

Well at this stage I don't buy  a repeat the middle of next week. Just an upper trough to the west is too vague and you only have to look at the latest GEFS anomaly to see why. Some warm weather I can go with at this stage but plume scenarios no. Can change of course.

http://www.tropicaltidbits.com/

Edited June 29, 2015 by knocker

[DR(S)NO]

Nice looking GFS charts on the latest run, hoping that tomorrow night does materialise here but I'm not too optomistic.

I'm pretty confident tomorrow night will materialise ....in fact I'm 100% sure ........BUT

[mushymanrob]

Sorry guys

Much though i like the gfs 12z pressure build next week with its associated heat and sun, the anomaly charts dont really support such a high...

Unless im wrong, just for a change lol.

[stodge]

Have to say I'm not quite sure if I'm looking at the same charts as everyone else sometimes, The GFS 12Z has continued the walk away from the potentially record-breaking heat modelled a few days ago. 

 

http://modeles2.meteociel.fr/modeles_gfs/runs/2015062912/54-582UK.GIF?29-12

 

Wednesday topping out at 31c over a wide area and I happily agree we could see a 32-33c to the north west of London. 

 

http://modeles2.meteociel.fr/modeles_gfs/runs/2015062912/102-582UK.GIF?29-12

 

Friday - again 31-32c around or to the west of London.

 

http://modeles2.meteociel.fr/modeles_gfs/runs/2015062912/126-582UK.GIF?29-12

 

Saturday - 32c in Norfolk but 30c elsewhere as the hottest of the air clips East Anglia briefly.

 

Hot, yes, unpleasantly humid, yes but exceptional - not for London and the SE though Wednesday might be an exceptional day in some parts of the country which can miss out on these plume events.

 

As for next week - warm/very warm certainly (25-27c) but I simply don't see the return of 30+ c heat.. Indeed, GFS 12Z OP FI confirms a sharp swing back to a positive NAO and a more "normal" synoptic flow with LP to the North and HP to the South and  to be honest the LP is the dominant factor as we move further into July. 

 

None of this precludes the return of heat later into July and August - Tamara certainly seems of the view the pattern will reset - maybe, but GFS isn't showing that at present and we need the progression of Atlantic LP systems to slow to enable pressure to rise over or to the east of the British Isles.

[Snowman.]

Have to say I'm not quite sure if I'm looking at the same charts as everyone else sometimes, The GFS 12Z has continued the walk away from the potentially record-breaking heat modelled a few days ago. 

 

http://modeles2.meteociel.fr/modeles_gfs/runs/2015062912/54-582UK.GIF?29-12

 

Wednesday topping out at 31c over a wide area and I happily agree we could see a 32-33c to the north west of London. 

 

http://modeles2.meteociel.fr/modeles_gfs/runs/2015062912/102-582UK.GIF?29-12

 

Friday - again 31-32c around or to the west of London.

 

http://modeles2.meteociel.fr/modeles_gfs/runs/2015062912/126-582UK.GIF?29-12

 

Saturday - 32c in Norfolk but 30c elsewhere as the hottest of the air clips East Anglia briefly.

 

Hot, yes, unpleasantly humid, yes but exceptional - not for London and the SE though Wednesday might be an exceptional day in some parts of the country which can miss out on these plume events.

 

As for next week - warm/very warm certainly (25-27c) but I simply don't see the return of 30+ c heat.. Indeed, GFS 12Z OP FI confirms a sharp swing back to a positive NAO and a more "normal" synoptic flow with LP to the North and HP to the South and  to be honest the LP is the dominant factor as we move further into July. 

 

None of this precludes the return of heat later into July and August - Tamara certainly seems of the view the pattern will reset - maybe, but GFS isn't showing that at present and we need the progression of Atlantic LP systems to slow to enable pressure to rise over or to the east of the British Isles.

Feel free to read back the last few pages were it has been discussed that the core heat has been shifted east. No one here is calling for record temps.

[East_England_Stormchaser91]

Have to say I'm not quite sure if I'm looking at the same charts as everyone else sometimes, The GFS 12Z has continued the walk away from the potentially record-breaking heat modelled a few days ago. 

 

http://modeles2.meteociel.fr/modeles_gfs/runs/2015062912/54-582UK.GIF?29-12

 

Wednesday topping out at 31c over a wide area and I happily agree we could see a 32-33c to the north west of London. 

 

http://modeles2.meteociel.fr/modeles_gfs/runs/2015062912/102-582UK.GIF?29-12

 

Friday - again 31-32c around or to the west of London.

 

http://modeles2.meteociel.fr/modeles_gfs/runs/2015062912/126-582UK.GIF?29-12

 

Saturday - 32c in Norfolk but 30c elsewhere as the hottest of the air clips East Anglia briefly.

 

Hot, yes, unpleasantly humid, yes but exceptional - not for London and the SE though Wednesday might be an exceptional day in some parts of the country which can miss out on these plume events.

 

As for next week - warm/very warm certainly (25-27c) but I simply don't see the return of 30+ c heat.. Indeed, GFS 12Z OP FI confirms a sharp swing back to a positive NAO and a more "normal" synoptic flow with LP to the North and HP to the South and  to be honest the LP is the dominant factor as we move further into July. 

 

None of this precludes the return of heat later into July and August - Tamara certainly seems of the view the pattern will reset - maybe, but GFS isn't showing that at present and we need the progression of Atlantic LP systems to slow to enable pressure to rise over or to the east of the British Isles.

Not sure if it even has displayed record heat from day one, only perhaps more than a week ago now. Highest I've seen modelled is 35-36c (not record breaking, but not far off), which by all accounts could well be achieved if conditions are perfect. 

Top marks to the models on picking up on this in FI more than a week or so ago. They've done quite a decent job on this. 

Edited June 29, 2015 by East_England_Stormchaser91

[Man With Beard]

A small shift in last 4 GEFS runs for Thurs/Fri and Sat; compare the two tables for London (18Z last night, and 12Z today) and you'll see the latest run has increased the uppers by 1 or 2C on average, and many ensemble members have the heat sticking around longer on Saturday:

 

http://www.meteociel.fr/modeles/gefs_table.php?x=306&y=141&run=18&ext=fr&mode=0&sort=0

 

http://www.meteociel.fr/modeles/gefs_table.php?x=306&y=141&run=12&ext=fr&mode=0&sort=0

 

Now fits fairly well with ECM for Saturday:

 

 

Extremely close to 35C in the SE corner I would think.

 

Further on, I have not forgotten the tendency that some models have to overestimate northern heights at times. The GFS op run has a wedge of heights to our north by T180:

 

 

but the following ensemble member does not:

 

 

I would expect the trough position at T0 to be somewhere between the two charts (at either end, or in the middle). The latter chart shows the following for uppers a day later, by the way:

 

 

Not saying to expect another plume by mid next week, but rather not to rule it out either

[mhielte]

Have to say I'm not quite sure if I'm looking at the same charts as everyone else sometimes, The GFS 12Z has continued the walk away from the potentially record-breaking heat modelled a few days ago. 

 

http://modeles2.meteociel.fr/modeles_gfs/runs/2015062912/54-582UK.GIF?29-12

 

Wednesday topping out at 31c over a wide area and I happily agree we could see a 32-33c to the north west of London. 

 

http://modeles2.meteociel.fr/modeles_gfs/runs/2015062912/102-582UK.GIF?29-12

 

Friday - again 31-32c around or to the west of London.

 

http://modeles2.meteociel.fr/modeles_gfs/runs/2015062912/126-582UK.GIF?29-12

 

Saturday - 32c in Norfolk but 30c elsewhere as the hottest of the air clips East Anglia briefly.

 

Hot, yes, unpleasantly humid, yes but exceptional - not for London and the SE though Wednesday might be an exceptional day in some parts of the country which can miss out on these plume events.

 

As for next week - warm/very warm certainly (25-27c) but I simply don't see the return of 30+ c heat.. Indeed, GFS 12Z OP FI confirms a sharp swing back to a positive NAO and a more "normal" synoptic flow with LP to the North and HP to the South and  to be honest the LP is the dominant factor as we move further into July. 

 

None of this precludes the return of heat later into July and August - Tamara certainly seems of the view the pattern will reset - maybe, but GFS isn't showing that at present and we need the progression of Atlantic LP systems to slow to enable pressure to rise over or to the east of the British Isles.

33C is likely IMO, and we *could* see a 34-35C, so not as far from record-breaking heat as you suggest, and if anything the 12z has increased the heat from the past few runs by one degree or so. ECM has followed suit I see.

[Captain Shortwave]

Current modelling suggests that the next 5 days could see 30C hit on any day (Tomorrow and Thursday being the least likely but the other days show the risk of temperatures going beyond 30C and into the low nineties in Fahrenheit). I would call that a solid hot spell even for this part of the UK. Other areas of central and northern England could get into the hot category at times with other areas warm or very warm too.

Sunday does look like being the day when temperatures do fall back but again only to average in north and still potentially very warm in the south. Into the following week, it won't take much considering the alignment of the jet to again bring widespread very warm or even hot conditions back in though at the moment the spells would be transient. That said there is always the chance of another set up to this week occurring where low pressure stalls west of the UK and allows the heat to surge northwards, pretty prominent considering the 20C isotherm is becoming increasingly an omnipresent feature even over central France by then.

Hottest days by 850s

Friday is hot due to a clearer and sunnier set up, well before the next front pushes northwards out of France.

The question for me is, will Wednesday be the hottest day (still going for 34C near Heathrow) or Saturday if the set up comes off.

[mushymanrob]

I reckon its great that the topic of discussion is 'will it get to 36c or 32c... Lol. The gfs backed down? Downgraded? Man i dont care and i guess many others dont because it IS going to be hot!

We can easily get temps of 30c + at this time of the year under high pressure, the sort the ecm 12z suggests we will get next week. We got home grown 30c plus in 2006, so we dont need a plume off the continent to get heat.

I cant see the imminent heatwave being the only one we get, it would be highly unusual if it were. Imho the outlooks good.

[Chris K]

Have to say I'm not quite sure if I'm looking at the same charts as everyone else sometimes, The GFS 12Z has continued the walk away from the potentially record-breaking heat modelled a few days ago.

http://modeles2.meteociel.fr/modeles_gfs/runs/2015062912/54-582UK.GIF?29-12

Wednesday topping out at 31c over a wide area and I happily agree we could see a 32-33c to the north west of London.

http://modeles2.meteociel.fr/modeles_gfs/runs/2015062912/102-582UK.GIF?29-12

Friday - again 31-32c around or to the west of London.

http://modeles2.meteociel.fr/modeles_gfs/runs/2015062912/126-582UK.GIF?29-12

Saturday - 32c in Norfolk but 30c elsewhere as the hottest of the air clips East Anglia briefly.

Hot, yes, unpleasantly humid, yes but exceptional - not for London and the SE though Wednesday might be an exceptional day in some parts of the country which can miss out on these plume events.

As for next week - warm/very warm certainly (25-27c) but I simply don't see the return of 30+ c heat.. Indeed, GFS 12Z OP FI confirms a sharp swing back to a positive NAO and a more "normal" synoptic flow with LP to the North and HP to the South and to be honest the LP is the dominant factor as we move further into July.

None of this precludes the return of heat later into July and August - Tamara certainly seems of the view the pattern will reset - maybe, but GFS isn't showing that at present and we need the progression of Atlantic LP systems to slow to enable pressure to rise over or to the east of the British Isles.

I don't understand. Most posts I have read haven't said there will be exceptional, record breaking heat? Infact people have been acknowledging the fact there it's less likely at the moment.

Again, people have only been mentioning that some hot spots might get temps a degree or two above the majority. And after that there is still uncertainty after this initial plume due to the close proximity of the Atlantic trough.

Not aimed at you, but the number of posts I have seen downplaying temps of mid twenties-low thirties is quite amusing to me. Only a short while ago there were endless moans about the constant temps of teens-low twenties and a nagging NW breeze.

All still to play for after this week tbh, even if it is to go back to "normal". The pattern of the jet looks ripe for reloads in my opinion but it's too far out in FI for me to think about at present.

Edited June 29, 2015 by Chris K

[Methuselah]

Uppers of circa 13C ought to sufficient, when combined with five-days' unbroken sunshine and very little wind?

[Frosty.]

There is a lot to like about the Ecm 12z run with high pressure next week becoming more dominant and no sign of a return to cooler, unsettled Atlantic weather. More charts like these through the rest of this summer will do nicely.

[Stuie]

Before next week though Frosty, Saturday in the SE looks like a cracker.

Edit: Sorry RJBW posted already.

Edited June 29, 2015 by SaffW

[Man With Beard]

Latest NOAA 8-14 anomaly

 

Still looking likely that the trough will be held out to our west (except perhaps creeping into NW areas). Still likely to be a block of some sort over the continent. Result: winds mostly drawn from a southerly quarter. Backs up tonight's ECM and the thoughts I posted above. Expect more heat at times next week then - likely to be more "normal" summer heat for the UK, though. Is it possible that 80F might be exceeded somewhere on each of the next 10 days?? (Sunday might be the dodgy day in the period)