Model Output Discussions 12z 03/05/2016

[Man With Beard]

Morning all, well yet more and more heat on this morning's runs and what a shock that would be to anyone who last looked at the models on Wednesday, where Arctic armageddon was on the charts!

The very best outrageously hot run in on the GEFS control run this morning, I thought I'd stick this in just for fun:

      

That's 48 hours with the 20C 850 line over the UK - 2003 like. GFS usually undercooks temperature charts so I dread to think what the maxes would be on this

Unlikely to be quite so dramatic - and of course a plume operates within a very small area so far from certain we would get the epicentre of it right now - but the ensemble table shows more runs are close to the Control run than not

Virtually nil rainfall for London over the forecast period, and though the drop-off in temps looks dramatic, the mean 850 temperatures remain close to 10C throughout.

That said, I can well understand the frustration of those in the north with charts this morning. We just still can't get those heights into northern areas in the reliable timeframe, at least if the ECM is right (GFS still fairly good even for Scotland):

  

Hopefully the T144 mean charts will hold out as Scotland will probably join in by then

  

Beyond the predicted hot spike for early next week - heights remain high over Scandinavia throughout D9-D12 on most GEFS 00Z ensemble members, with a few actually pushing heights back towards the UK - so difficult to call as we would be on the edge of the continental air - possibilities both ways of remaining very warm/dry and also of being more slightly under the influence of the an Atlantic trough, but still with a bias towards weather from the S or SW.

Latest GFS running out and it's more of the same, by T168 it's warm or hot pretty much nationwide with more to come

  

Anyone who bet 17C or more for the CET is looking fairly good right now.

 

[Frosty.]

The Gfs 6z op run shows another spanish plume early next week with temps reaching the low to mid 90's F and a risk of thunderstorms breaking out in the hot and sultry conditions but before all that, high pressure builds in across the south by friday and then becomes centred right over the uk by next weekend bringing warmer and settled weather to all before the high drifts east and enables hot continental air to drift north into the uk with a hot and humid first half to next week, the heat lasting through to next midweek before it becomes pleasantly cooler and fresher but still with occasional ridging across the south bringing more fine and pleasantly warm weather..it looks like plume No2 is on the way according to the gfs / ecm & gem.

Edited August 8, 2016 by Karl.

[Frosty.]

The GEFS 6z mean also supports our second spanish plume this summer which would beat last summer! It's looking good for later this week, the weekend and first half of next week if you love summery weather as I do, becoming dry, sunny and warm / very warm. Temps look like reaching the mid 20's celsius next weekend and then it becomes hot and humid  into the low 30's c and potentially close to 34 / 35c in favoured spots which would be higher than the earlier plume this summer, there is an increasing chance of thunderstorms next week. The other good news is the Azores high looks friendlier than on the 00z and nice height rises across scandinavia. It's looking good for the rest of this summer..much better than June!

[stodge]

Afternoon all

I think we've some way to go before we can call next week's "plume" in terms of longevity and intensity.

As an example, the 00Z OP at T+210 had this:

The 06Z OP at T+204 has this:

The former shows the hottest of the air already on the way out - the latter has the 20c line across southern England and a horrible sweaty night for most of the population as a result.

ECM 00Z OP kept the hottest air for Thursday rather than Tuesday while GEM goes for Wednesday:

In short, a huge degree of uncertainty for an event which is still in low-res. The possibility of a hot spell next week is clear as indeed was the possibility of the so-called "arctic Armageddon" last week but it could intensify or it could be flattened out. GFS is a 24-36 hour hot snap while GEM's hot spell might be of longer duration. The question is whether the HP to the east will be sufficiently robust to act as a block which could keep the British Isles under hot, thundery conditions as the Atlantic tries to push in or whether the Atlantic will push through more quick;ly and we'll be into fresher air.

 

[Costa Del Fal]

Given the high pressure that looks to set up to our east (and especially if it sits over Scandinavia) seems likely to be a fair deal stronger than the one that brought the July plume, I would be surprised if the Atlantic found it so easy to sweep through this time. Wouldn't be surprised to see the Atlantic attack delayed somewhat - has happened a fair few times before if I am correct. 

Also looks to be a possible good scope for a rinse and repeat pattern. Even if the Atlantic does break through somewhat, I am not seeing troughs wanting to sit over us. The core of low heights looks to be well to our NW in the upcoming period.

[Man With Beard]

Good post Stodge (and CDF) - I count 8 out of 21 GEFS ensembles that keep the really strong heat until at least Thursday next week - but it's precarious as it all relies of a very direct line of air from Spain northwards. Could still miss us completely in all honesty.

 

Edited August 8, 2016 by Man With Beard

[Scorcher]

59 minutes ago, Man With Beard said:

Could still miss us completely in all honesty.

 

This would be very surprising I think- just the likely evolution would suggest that the UK would have to be hit by the heat at some stage.

The high is going to edge eastwards and as this happens it is going to draw the very warm air up from the south.

The question marks for me are simply for how long it's going to last.

[Gordon Webb]

1 hour ago, Man With Beard said:

Could still miss us completely in all honesty.

 

yep might do but when a POTENTIAL plume is spotted heat charts get thrown around like confetti and any differing opinion is met with cynicism despite the fact that this is over a week away , me when the same type of charts are there on Friday then I might concur with the plume scenario but seems a little early to cheer and celebrate

[Yarmy]

 

These charts that are appearing for mid-month look like the Schafernaker Southerly that he mentioned in his BBC forecast a while back (last Sunday?). 

[coldcomfort]

49 minutes ago, Scorcher said:

This would be very surprising I think- just the likely evolution would suggest that the UK would have to be hit by the heat at some stage.

The high is going to edge eastwards and as this happens it is going to draw the very warm air up from the south.

The question marks for me are simply for how long it's going to last.

Agreed, I think the odds of a complete miss are probably the same as a week long heatwave, i.e very low. That said there will be some places that avoid any heat, especially across the far northwest and even the most favoured spots in the E/SE of England are probably looking at 48-72hrs tops. Whether we can see some sort of reload thereafter remains to be seen, but there is a real danger that a deep trough lying from Iceland to the UK will prevent the AZ and Scandi HP's from linking, trapping us into a cool, unsettled pattern for week 4 of Aug. 

Edited August 8, 2016 by coldcomfort

[Captain Shortwave]

45 minutes ago, Gordon Webb said:

yep might do but when a POTENTIAL plume is spotted heat charts get thrown around like confetti and any differing opinion is met with cynicism despite the fact that this is over a week away , me when the same type of charts are there on Friday then I might concur with the plume scenario but seems a little early to cheer and celebrate

To be fair there has been a strong signal for a ridge to develop to the east of the UK for a fair while now, this was actually mentioned a week ago by the BBC for a potential trend that was scoffed at by many. It is fair to say that this is starting to bear fruit now.

ECM ens

   

   

GFS ens are similar.

A good signal for conditions to turn hot across the south and warm/very warm for most parts of the UK as high pressure builds through and then to the east of the UK next week, the question is how hot could it get and how quickly we see a breakdown. That is what we need to look at, both the ECM and GFS have temperatures well into the 30s in the 7-10 day range which is a good sign, can we keep this trend into the semi reliable 5-7 day range and could we see this developing ridge offer some greater resistance to an Atlantic attack. 

 

Edited August 8, 2016 by Captain Shortwave

[Summer Sun]

Very little change from GFS so we'll be at the potential heatwave charts within the next 10 minutes

[Man With Beard]

2 hours ago, Scorcher said:

This would be very surprising I think- just the likely evolution would suggest that the UK would have to be hit by the heat at some stage.

The high is going to edge eastwards and as this happens it is going to draw the very warm air up from the south.

The question marks for me are simply for how long it's going to last.

I actually agree but I'd posted so many heatwave charts at T216 I thought I'd better throw in some caution!

12Zs so far - UKMO looks like the heat is getting into gear nationwide by Sunday - GFS, well what can I say, even hotter than the 06Z if that were possible, looking at somewhere between 32C and 35C again next Tuesday ... IF IF IF it verifies!

[northwestsnow]

Not sure those across the south east would want GFS12Z to verify, overnight temps of 24 to 25 degrees (well at midnight next tues) is bordering on unbearable with out a fan at the very least.

Prior to that its in the warm/very warm cat for much of the south from late this week onwards..

Last hurah for summer coming up? i expect the plume to be quite brief if it does verify i might add

[Frosty.]

3 minutes ago, northwestsnow said:

Last hurah for summer coming up? i expect the plume to be quite brief if it does verify i might add

The experts are on-board with the models about it turning hot and humid next week with lots of hazy sunshine followed by a thundery breakdown..amazing as its still a week away but confidence on a plume is high.

[I remember Atlantic 252]

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very hot, Wed, like Wed 01 July last year

Edited August 8, 2016 by I remember Atlantic 252

[bryan629]

11 minutes ago, northwestsnow said:

Not sure those across the south east would want GFS12Z to verify, overnight temps of 24 to 25 degrees (well at midnight next tues) is bordering on unbearable with out a fan at the very least.

Prior to that its in the warm/very warm cat for much of the south from late this week onwards..

Last hurah for summer coming up? i expect the plume to be quite brief if it does verify i might add

Was just looking at that as well .... 2m temps at 2.00am ... Thats going to be a heck of a night for sleeping, Thats for sure  and we all know how GFS likes to undercook temperatures..EEK!!

[Frosty.]

I don't know if anyone has posted the ukmo 12z for next Sunday but it's looking warm and anticyclonic..another good weekend coming up.

Edited August 8, 2016 by Karl.

[I remember Atlantic 252]

2 minutes ago, Karl. said:

I don't know if anyone has posted the ukmo 12z for next sundsy but it's looking warm and anticyclonic..another good weekend coming up.

hope so Frosty, hope GFS is wrong

[bryan629]

Still along way off ..GFS now advertising some cracking fireworks for certain areas... 

[Fourty Point Three Degrees]

gfs 12z is a nice upgrade on recent runs, very hot in france 40c for most of next week and 33c possible for most of England.  Looks like its onto something big here, another 2003 perhaps? 

[Man With Beard]

1 hour ago, 40*C said:

gfs 12z is a nice upgrade on recent runs, very hot in france 40c for most of next week and 33c possible for most of England.  Looks like its onto something big here, another 2003 perhaps? 

Upgrade? It's a flipping NUCLEAR upgrade! 850s of 20C plus on 3 days! Over 16C in the SE for five days! It's the greatest run for heat ever apart from 2003

Edited August 8, 2016 by Man With Beard
mixed up the posts!

[SMU]

Afternoon All-

Todays runs are touting the kind of flow that is like the holy grail for heat as is the mythical easterly in Winter

To get upper air temps of above +20c over the UK ( rather like -15c in winter ) does take a rather unique set of circumstances - most importantly that direct southerly flow with substantial High pressure to the east, the High needs to remain in Situ long enough fo that +20c isotherm to be pumped Northwards -

More recent summers havent seen high Pressure remain stable & in situ long enough for this to happen - mainly as the atlantic has ushered in more unsettled weather before the plume gets going- consequently the hottest air generally curves NE into France-

Its looking good this time though- I suspect the Ensemble peak will be up around 17-18c this afternoon - it will be another 48 -72 hours before the detail around the illusive 20c line can be persued with a little more confidence-

To chase North of 36c we would need more than 2 - 3 stable days- .... You never know

s

Edited August 8, 2016 by Steve Murr

[Summer Sun]

3 minutes ago, Man With Beard said:

I actually agree but I'd posted so many heatwave charts at T216 I thought I'd better throw in some caution!

12Zs so far - UKMO looks like the heat is getting into gear nationwide by Sunday - GFS, well what can I say, even hotter than the 06Z if

Upgrade? It's a flipping NUCLEAR upgrade! 850s of 20C plus on 3 days! Over 16C in the SE for five days! It's the greatest run for heat ever apart from 2003

 

I wouldn't rule out hitting 100f next week if the charts remained as they are today if we can get 34c or whatever it was from a one-day hot spell imagine what we could reach if it goes on for 3 days or so

[Frosty.]

That must be the longest plume ever on the Gfs 12z and even beyond it looks summery. In a misfiring summer that would be an amazing way to end it!