Model Output Discussion 12z 30/06/13

[Milhouse]

The usual hot spots (i.e, the SE and E Anglia) may not necessarily be the hottest places next week, depending on the orientation of the surface high which will affect the flow. If the flow's from the east off the cool North Sea, as appears on GFS towards the SE, southeastern areas will be cooler (though still pleasantly warm) with northern and western areas seeing the highest temperatures, though sea breezes developing during the day may mean all coastal areas are cooler than inland.

 

i was looking at some records for Spurn Point which is a very remote spit of land jutting out into the North Sea at the Humber Estuary. During the 1976 heatwave it still got to 20 or 21c with an onshore breeze, so the point is it could still feel warm on the coast and go 10 miles inland and the temperatures should be several degrees higher.

 

The GFS 0z is just epic. The chance of at least mid 20s right out to the 18th.  Its a shame it will be soon erased by the 6z.

[Milhouse]

Paul Hudson on Look North mentioned temperatures up to 27c by the weekend in Yorkshire. Not often is it announced so much in advance given recent failings so the Met Ofice must be pretty confident about this. Looking at the models i can see why. They have been consistent in showing a strong area of high pressure developing and lasting

Temperatures up to 23c for Thursday so not long now before the warmth arrives.

 

[nitro_deluxe]

I do believe a 32c shall be achieved possibly even slightly breached - NW London, Home Counties, maybe into Reading, Berkshire.

[Geordiesnow]

The UKMO is an improvment than on last nights UKMO run in terms of the orientation of the high, still a risk of the front affect the far NW Scotland but the orientation of the high would suggest the front should not topple over other areas and that it should instead back NW'wards into the Atlantic so even the far NW can join in with the sunshine and warmth. 

 

The GFS however has the orientation less favorable and we can see on the PPN charts that the front will topple in during Saturday and for some Northern areas Sunday could be cloudy with that weak front over us, it should eventually fizzle away but I'm not being fooled by the GFS charts that it will be blue skies and sunshine nationwide because this might not be the case.

 

Hopefully the GFS is wrong in tempory sending the high just to the West of which would allow that front to topple in, ECM/UKMO is the way to go! 

[Frosty.]

The Ecm 00z ensemble mean is absolutely fabulous with a hot anticyclonic outlook for all of the uk, there is a risk of a few isolated heavy showers or storms breaking out in the heat of the day but most areas would just be sunny and hot with temperatures in the 80's F, given the alignment and position of the high, high 20's to low 30's celsius would be realistic, a heatwave if ever I saw one.

[BornFromTheVoid]

Can anyone more knowledgeable make a synoptic comparison with July 2006?

 

Looking at the chart for back then, that was a genuine Euro high much further East, which I imagine created a hot tropical Southerly but other than the placement of the anticyclonic centre, the latest ECM and GFZ 00z don't look that far off to my novice eyes...

 

The current forecast set up for the warm spell has some similarities 2006.

 

Here are four charts showing the evolution towards the high pressure warm spell from 2006, and what's forecast this year.

 

 .......2006 .............. ................. .................. .........2012

 

 .......2006 .............. ................. .................. .........2012

 

 .......2006 .............. ................. .................. .........2012

 

 .......2006 .............. ................. .................. .........2012

 

So not identical, the ridging and pressure were a little stronger in 2006, but quite a similar evolution projected.

 

As Tamara correctly points out, what we felt on the ground was quite different between June 2006 and this year, but overall, the upper air pattern had some very strong similarities.

 

June 2006 500hPa GPH................................ June 2012 500hPa GPH

 

With the teleconnections and background signals, the similarities between this summer and 2006 are quite strong.

Both had +ve AO and NAO Junes.

Both had +ve PDO May and June.

Both had +ve AMOs.

Both had +ve and rising QBOs

Both had weak ENSO values

Both had similar Arctic sea ice levels

Both had large -ve hemispheric snow cover anomalies from late Spring

 

A lot of matching signals there which, back in early May, I used to produced a July composite of comparable years to this one (69,01,06,11).

 

While I don't believe this will lead to another July 2006 this year, weather never being that simple, I think a taster of 2006 would be great after the recent run of summers we've had, and it seems the first summer heatwave in a long while is just around the corner

[bringmesunshine]

Exactly one year ago today (remember it because it was the day after the torch relay in Leamington) we were discussing a set of apocalyptically bad summer charts with a mixture of despair and grim humour. It genuinely looked as though we were never going to see another long lasting heatwave again in this country, the patterns seemred so locked in.

What a difference a year makes. We're not there yet, these are computer predictions after all, and as a self confessed heat lover but respectful of other's preferences, I can see how today's charts might not please everyone. That's fine - but if you do like summer heat and you're still not happy this morning then you really need to find something else to do.

So happy for guys like Gavin and Frosty, the eternal optimists who, let's face it have often been subject to a degree of ridicule on these pages. And grateful to all others who have made sense of the bewildering amount of data - especially Tamara and JH for their caution which always helps to keep our feet on the ground. Hopefully, you will all enjoy (literally) your day, or even days, in the sun next week.

[Geordiesnow]

The 06Z is an improvment, Saturday's front is further Westwards and not as much cloud should topple in as was the case on the previous run. There does seem to be a shift of emphasis on the GFS runs that the warmest conditions could be the further Northwards and Westwards you are, could turn out to be one of the best summers for a very long time in some western areas. 

 

Also good too see that Friday is turning to be warmer and probably sunnier than first thought so a nice upgrade there. 

[Downpour]

There are differences to 2006 and we have come from a much cooler background than 2006 - despite the fairly cold start to the Spring that year. The anticyclonic type pattern began right at the start of June, and as you say, it featured migrating cells just to the east of the UK with a lot of hot southerly winds, plus a slight weakness of pressure over the Azores, and this pattern recycled several times all the way up to August.

 

As we know, this fine spell is starting some 5 weeks later and looks to feature an extension of the Azores High to the UK, with our Island and into NW Europe being the eastward cell of this High pressure belt. The fine spell is yet to begin, so we will have to wait and see how it develops further and there is a long way to go before we can compare it with years like 2006, 1990, 1983 and 1976 etc.

 

All that said, the models suggest a spell that is sustained enough to give us a good week or so at least of gloriously fine summer weather. Its hard to criticise for sure, but being one who prefers pleasant warmth than than searing heat - I will be grateful for that gentle easterly breeze where I live.

 

The EPS members are emphatic in their alignment for High pressure mostly straight over the UK out to day 7 from here. There is less sign of the retrogression tendency than yesterday, which suggests that although, eventually, this could prove to be the correct signal, the thought the models may try to be too progressive with this signal could prove to be true

 

It has to recede at some point Tamara. Not even the most cock-eyed heat fan would expect a high pressure like that to run until mid September. What I would say about this summer is that dry is the form horse. We will have cooler, cloudy spells and we will have warmer, sunnier spells. But rain is a rare commodity, and may soon become a precious one. What a contrast from recent summers – and what an irony given the "ten years of wet summer" schtick we have seen from the Office/press

Edited July 2, 2013 by Downpour

[Summer Sun]

Once again this morning GFS still wants to pull the high back as we progress through next week the weekend and the first part of next week looks very warm to hot away from the east coast where temperatures will disappoint many here with the high teens to low 20's at best in the easterly wind

 

 

Sunday see's the heat building but again those in the SE who are exposed to the wind struggle to get above 20c

 

 

And the trend continues into the working week some parts of Scotland are hotter than the South east which is very rare possibly 28c in Edinburgh on Tuesday just 18 to 20c for Norwich

 

 

As the weekend comes around the warmth heads south into Mainland Europe and the rain arrives

 

 

The following week starts how the weekend ended cooler and probably cloudier

 

 

So if you want to enjoy the heat next week the south east still looks the place to avoid

[NUT]

Seems to GFS that the heat up here on tuesday will cause the atmosphere to go bang (unless i'm mistaken) although I know very likely it will change

[Summer Sun]

The 10 day precipitation outlook does suggest some homegrown showers and possibly thunderstorms will develop next week for a few

 

 

 

They do look hit and miss but parts of Scotland have a good chance at the moment if GFS is correct the heat will leave on a quiet note which seems to be quite common these days in the UK thundery breakdowns seem to be as rare as a heatwave in summer these days

 

[Backtrack]

Once again this morning GFS still wants to pull the high back as we progress through next week the weekend and the first part of next week looks very warm to hot away from the east coast where temperatures will disappoint many here with the high teens to low 20's at best in the easterly wind

 

 

 

Sunday see's the heat building but again those in the SE who are exposed to the wind struggle to get above 20c

 

 

 

And the trend continues into the working week some parts of Scotland are hotter than the South east which is very rare possibly 28c in Edinburgh on Tuesday just 18 to 20c for Norwich

 

 

 

As the weekend comes around the warmth heads south into Mainland Europe and the rain arrives

 

 

The following week starts how the weekend ended cooler and probably cloudier

 

 

So if you want to enjoy the heat next week the south east still looks the place to avoid

 

 

Now how often is it we hear that on this thread?!

[Frosty.]

There are just a few more chinks in the armour of the Gfs 06z operational compared to the 00z as the large anticyclone drifts around and occasionally into less favourable positions through FI but this run is a significant upgrade on the 6z yesterday in both longevity and intensity of the heatwave which on this run persists from the weekend (bar the far northwest at first) until the following weekend and even beyond that, there is more warm and settled weather at times further southeast. It's rare for a nationwide heatwave to develop in the uk on recent years evidence but it now looks like we are going to have hot sunshine for just about the whole of the uk, even the eastern coastal strip looks warm and sunny but with refreshing sea breezes springing up, but just a little way inland it will be hot, coastal temps of 21-22c but inland, 26-29c and possibly 30-32c in the hottest spots next week.

 

So in summary, the next few days are more unsettled with some rain and showers but with some brighter and warmer spells especially across the south and southeast, the rain and stronger winds generally further north although tonight brings a band of heavy rain across england & wales. By friday the low pressure is gone and high pressure is building strongly, just at first this weekend the far northwest, western isles & northern isles have active fronts brushing northeastwards around the top of the building anticyclone but by sunday onwards it looks dry, sunny and hot across practically the whole of the uk, just a small risk of a heavy shower in scotland on sunday and perhaps an isolated storm elsewhere next week due to the increasing heat and a slight rise in humidity levels, but most of the uk look sunny and hot with only small amounts of fair weather cloud bubbling up and some areas could be sunny from dawn until dusk.

Edited July 2, 2013 by Frosty039

[rmc1987]

London doesn't look like it'll see the highest temperatures. Currently showing 25c for weekend, not quite heatwave of course, so similar to the weekend gone it would seem.

Towards the south coast or even midland area would see the highest temperatures.

[WheresTheSnow]

I think the GFS predicted 25C for London on Sunday but reached 27C I think at Heathrow. So I believe temperatures will still be hot in London, though it does look like further North/West will see the hottest temps from looking at the GFS.

[Summer Sun]

Now how often is it we hear that on this thread?!

 

I know its extremely rare but next week it looks like its going to happen the extremely cold start to spring is to blame as the north sea is still cooler than normal

 

The wind doesn't look too strong probably 10 to 20 mph but it will be enough to keep temperatures a lot fresher than else where

 

 

Even into the weekend there is no let up in the cool wind

 

 

Now another look at cloud amounts all times are 18:00 BST

 

Sunday see's parts of Scotland and Northern Ireland start cloudy but this slowly lifts during the day for the rest of the UK it looks sunny and warm to hot the cloud may be thick enough across northern England to turn the sun a bit hazy but that's the exception

 

 

Monday is sunny UK wide however as the day goes on some thunderstorms could develop in parts of Scotland

 

 

Tuesday is a repeat of Monday sunny UK wide however as the day goes on some thunderstorms could develop in parts of Scotland with the heat of the day

 

 

Wednesday could see some more high level cloud across the country it may turn the sun hazy in places but it shouldn't affect it too much

 

 

Thursday see's thicker cloud moving into Scotland and again high cloud over the UK could turn the sun hazy at times the cloud over Scotland is a sign of things to come

 

 

Friday see's thicker cloud across the UK with rain possible as well this is also the last UK wide hot day according to GFS

 

 

Saturday again see's thick cloud across the country and rain becomes more widespread with this temperatures tumble apart from the south coast who keep the warmth for one last day

 

 

Sunday once again sees thick cloud across the country with lower temperatures for all and some rain

 

 

The return to cooler unsettled conditions later next week has been on a few runs from GFS now over the past few days so its going to be a case of wait and see how things progress over the coming days

Edited July 2, 2013 by Summer Sun

[TonyH]

Funny how the long standing Doubting Thomas's, sheds and mushys stop posting when a prolonged heatwave seems inevitable! At least we still have Tony27..

[Rammie]

Prolonged heatwave? Mmmm....

[TonyH]

Well at least a week of warm to hot!

[Evening thunder]

It has to recede at some point Tamara. Not even the most cock-eyed heat fan would expect a high pressure like that to run until mid September. What I would say about this summer is that dry is the form horse. We will have cooler, cloudy spells and we will have warmer, sunnier spells. But rain is a rare commodity, and may soon become a precious one. What a contrast from recent summers – and what an irony given the "ten years of wet summer" schtick we have seen from the Office/press

 

 

Certainly seems that way so far here at least, could do with a decent soaking at some point probably. About the MetO thing bear in mind that the '10 years of wet summers' was the media and press' interpretation, the Met Office just said it just weights the changes slightly in favour as far as I remember.

 

I reckon the 06z is under-doing maxima slightly across the south into next week, as it shows 850hpa temps near 15C.

http://cdn.nwstatic.co.uk/gfsimages/gfs.20130702/06/156/h850t850eu.png

It tends to do this when it shows a bit more of a breeze compared to when winds are shown very light or calm. I notice when there's a bit more of a breeze shown it usually knocks a few degrees of maxima compared to when it is showing calm when it can get maxima right or even show them too high, similar with minima it often predicts them too low when winds are shown near calm, but several degrees higher and perhaps closer to reality if there's a slight breeze shown, if any of that makes sense! 

I've seen this several times with warm weather and an easterly surface breeze in the south, I'd expect more widespread high 20's and perhaps the odd 30C with the high pressure and uppers shown into next week, rather than widespread mid 20's and the odd high 20's the GFS shows. (e.g last May had 27.5c here under 12-13c uppers with an E breeze, GFS went for something like 24 I think). Anyway this is just speculation on the 06z details but the ECM shows similar uppers.

 

Also personally I think much of the SE looks warm, very warm to hot (probably mid to high 20's) times once you get to London or west of there I'd think, Perhaps not quite the hot spots unless an easterly surface flow dies away sometime during this spell which is quite possible, but it's really only the parts of EA and the SE closer to the east coast I'd expect to be notably cooler, perhaps most of Kent in particular looking at the GFS wind charts.

[Gray-Wolf]

 What a contrast from recent summers – and what an irony given the "ten years of wet summer" schtick we have seen from the Office/press

 

Maybe they weighted their conclusions wrongly and should have looked more to the arctic changes for the driver of the Jet's recent 'excursions' . to me it is no mistake that , post another 18% drop in ice levels, we should see a similar 'switch' to the one we saw with the 07' 22% drop in ice cover?

 

Shift the jet on a cycle and troughs become peaks and peaks become troughs ( sorry Mid europe but it's your turn now!)

[Downpour]

Certainly seems that way so far here at least, could do with a decent soaking at some point probably. About the MetO thing bear in mind that the '10 years of wet summers' was the media and press' interpretation, the Met Office just said it just weights the changes slightly in favour as far as I remember.

 

I reckon the 06z is under-doing maxima slightly across the south into next week, as it shows 850hpa temps near 15C.

http://cdn.nwstatic.co.uk/gfsimages/gfs.20130702/06/156/h850t850eu.png

It tends to do this when it shows a bit more of a breeze compared to when winds are shown very light or calm. I notice when there's a bit more of a breeze shown it usually knocks a few degrees of maxima compared to when it is showing calm when it can get maxima right or even show them too high, similar with minima it often predicts them too low when winds are shown near calm, but several degrees higher and perhaps closer to reality if there's a slight breeze shown, if any of that makes sense! 

I've seen this several times with warm weather and an easterly surface breeze in the south, I'd expect more widespread high 20's and perhaps the odd 30C with the high pressure and uppers shown into next week, rather than widespread mid 20's and the odd high 20's the GFS shows. (e.g last May had 27.5c here under 12-13c uppers with an E breeze, GFS went for something like 24 I think). Anyway this is just speculation on the 06z details but the ECM shows similar uppers.

 

Also personally I think much of the SE looks warm, very warm to hot (probably mid to high 20's) times once you get to London or west of there I'd think, Perhaps not quite the hot spots unless an easterly surface flow dies away sometime during this spell which is quite possible, but it's really only the parts of EA and the SE closer to the east coast I'd expect to be notably cooler, perhaps most of Kent in particular looking at the GFS wind charts.

Yes, agreed. Does the GFS account for urban heat trapping? That often comes into play in a big way during these sorts of setups with London showing the warmest temps at around rush hour due to the thermal lag on the buildings. It's actually a very unpleasant sensation that – that concrete storage heaters are supplying the heat rather than the sun. 

[Methuselah]

Maybe they weighted their conclusions wrongly and should have looked more to the arctic changes for the driver of the Jet's recent 'excursions' . to me it is no mistake that , post another 18% drop in ice levels, we should see a similar 'switch' to the one we saw with the 07' 22% drop in ice cover?

 

Shift the jet on a cycle and troughs become peaks and peaks become troughs ( sorry Mid europe but it's your turn now!)

What's that got do with model outputs?

[Summer Sun]

Well apart from a few colder member the ensembles continue to stay warm and mostly dry I say mostly as the spikes do increase over time the further north you go

 

London is the warmest and driest ensemble with no increase in the spikes until the end of the run at the earliest

 

 

The Manchester, Aberdeen and Dublin ensembles see increases in the spikes from the 13th but totals still remain well below normal