Model Output Discussion 12z 08/07/13

[WheresTheSnow]

We are now entering the warmest part of the year so we dont need exceptional charts to deliver very warm conditions. The GFS 0z and 6z both showed a very warm, locally hot weekend in the south and the warmth persisting into next week with any rain bands mostly fizzling out and not amounting to much at all. All areas will see a breakdown of high pressure but as far as the settled and warm conditions are concerned its the northern half of the UK which will see these being removed from Sunday onwards. The southern half will continue fine and very warm.

The 06Z keeps it warmer for a bit longer for most of Central, Northeastern and Southern England going into Tuesday. This run shows it only getting noticeably cooler in Scotland, Ireland, Northwestern England and part of Wales. 

As we can see the heat is slowly fading away here, but not for long on this run as High pressure tries to reassert itself over the UK later in FI:

All in all, a nice run there with some encouraging signs for High pressure to rebuild over most of the UK by next weekend. 

[Buzzit]

Heights getting a bit further west on GFS 18z vs 12z, and the trend is in disagreement with ECM, that's all I'm saying.

 

Oh look the -10 850s reform over Greenland at 372 lol 

 

Good spotting ! At least it is later than yesterdays 6z (I will keep saying bonkers while the 6z continues to throw up bonkers chart output). Someone tell me it is a trend go on lol

Edited July 10, 2013 by Buzzit

[Tim Bland]

Before people get carried away with the reload it's worth noting that the last 3 op runs on GFS were mild outliers on the ensembles.

[JK1]

Oh look the -10 850s reform over Greenland at 372 lol 

 

what does that mean?

[Scorcher]

Before people get carried away with the reload it's worth noting that the last 3 op runs on GFS were mild outliers on the ensembles.

 

The ECM 00Z also seems to be hinting at it though later in the run, will be interesting to watch how it develops on the next few runs.

[Captain Shortwave]

Before people get carried away with the reload it's worth noting that the last 3 op runs on GFS were mild outliers on the ensembles.

That may be but there is good support for the Azores high to rebuild

 

That's excellent for a day 10 mean.

ECM at the moment is not so keen on the idea so more runs are needed but the signs are there.

[shedhead]

Control and Op MSLP both consistantly above the mean post T+180hr, but the pressure rise reload is definately not without some

degree of support.

 

As for the 850's...there's simply no denying that the op was pretty much top of the shop, with the mean some 5c lower in FI.

 

[Milhouse]

A fine and promising 6z GEFS mean thats for sure. This chart for next Tuesday is the coolest, most unsettled of the next 10 days (still mid 20s in the south) before high pressure builds from the Azores. So its insignificant if the 6z op was an outlier because of what the mean is still supporting a decent rebuild of high pressure.

 

[Frosty.]

The Ecm 00z ensemble mean shows the heat soon building again after the relatively cooler and cloudier blip for some areas today, temperatures will then rise into the mid to high 20's celsius again, at least for the southern half of the uk and the warmth and sunshine is set to continue through the weekend into the start of next week across more southern areas, slowly trending cooler and fresher further north with less settled conditions but the south remaining warm or very warm until the middle of next week, whilst it looks like briefly becoming a bit more unsettled with the airflow becoming more westerly, there are already signs that the azores/atlantic anticyclone will just be waiting in the wings to bring a return to the very summery conditions, if not by the end of next week, soon after, there is some backing for this idea from the earlier 00z output.

[Milhouse]

The fear of cooler air slipping south on Saturday into Sunday looks to have been removed now. This was indicated by the GFS more so than the UKMO and ECM but now all 3 are pointing towards a fine and warm Sunday as well as Saturday.

 

[Buzzit]

Before people get carried away with the reload it's worth noting that the last 3 op runs on GFS were mild outliers on the ensembles.

Scrap my post the ensembles below speak for themselves

Edited July 10, 2013 by Buzzit

[Evening thunder]

what does that mean?

 

Probably not much considering most of Greenland is higher than the 850hpa (about 1,500m) pressure level anyway. This is a question I've sometimes wondered, why do the models show the temp at 850hpa over Greenland when over most of Greenland that elevation is buried under up to 2,000m of ice! and as such could we count a -10c 850hpa shown over Greenland as the first of a season as it won't actually exist in real life)

 

for what it's worth, the 06z shows -10c 850's at 00 hours: http://cdn.nwstatic.co.uk/gfsimages/gfs.20130710/06/00/h850t850eu.png

but the 850hpa temps are much higher than surface temps there, http://cdn.nwstatic.co.uk/gfsimages/gfs.20130710/06/00/maxtemp.png

probably showing how the surface temps have an elevation much higher than the 850hpa temps.. lol

 

Sorry if this isn't strictly UK related, Others have summed up what I could have to say really.

[Buzzit]

By the way if you do use the London charts above a small tip is that if you use

http://176.31.229.228/modeles/gens/graphe_ens3.php?x=306&ext=1&y=141&run=6&ville=Londres&runpara=0

Go to where "run=6" appears in the web address and you can change the "6" to 0,6,12,18 to see the four most recent runs ensembles

Edited July 10, 2013 by Buzzit

[Frosty.]

The latest met office update shows a north/south split, northern britain becoming cooler and more changeable but the south of the uk having a lot of dry and sunny weather with above average temperatures and very warm at times, this also goes for the further outlook, sunniest and warmest in the south, coolest and cloudiest in the north, however, this is just a bare bones picture and does not take into account the likelihood that the north will have some occasional spells of warm and fine weather, which i'm sure they will since the gefs and ecm mean are indicating a return of the generally warm and settled pattern after a more changeable and less warm blip next week but the south of england is likely to be on the warm side throughout this period with temperatures above 22c by day, sometimes well above.

[Sweatyman]

Sorry delete above, would we be talking fine for Wales/midlands as in 'the south' frosty?

[Frosty.]

Sorry delete above, would we be talking fine for Wales/midlands as in 'the south' frosty?

yes, i'm thinking wales, across the midlands and east anglia southwards for the predominantly warm/very warm and generally fine outlook, whilst it does look warm and fine for most of the time, there will be some shortlived interruptions but it's much better for the south than the north.

[Backtrack]

I think this would roughly represent what the weather will be like beyond Sunday

 

Green = Cooler, prone to showers/longer spells of rain

Orange = Warm & mostly settled

Red = Very warm & mostly settled.

 

[Geordiesnow]

I think the North-South split in the MO forecast seems pretty reasonable to what we are seeing in the charts, hopefully the GFS trends of trying to ridge the Azores high come into play instead of the trough digging down delivering cooler but still not particularly wet conditions. 

 

The one thing to note in the outputs is that none of them look particularly wet so those hoping for some rain will be disappointed, the only area that might be risk at something more heavier for the foreseeable future will be in Western Scotland especially if the trough digs down as per the UKMO run. 

[Frosty.]

The Gefs 06z mean is very encouraging the further south you are with high pressure building in strongly again next week after a bit of a changeable blip, the southern half of the uk becoming sunny and very warm again, indeed, southern england is warm throughout and mostly very warm, scotland & n.ireland are set to turn cooler and more changeable with an atlantic airflow but still with some fine and warmer intervals.

 

As for the coming days, hotting up quickly again across the southern half of the uk with temps in the mid to high 20's celsius and plenty of sunshine and a hot & sunny weekend to come in the south but progressively cooler and a little more unsettled the further north you are but rainfall totals look small although there could be some heavy showers breaking out across the south this weekend due to the heat and increasing humidity.

Edited July 10, 2013 by Frosty039

[Milhouse]

Northern England expected to be 5-7c warmer in on Friday compared to tomorrow.

 

[cheese]

Northern England expected to be 5-7c warmer in on Friday compared to tomorrow.

 

I am expecting the first 30C of the year on Friday somewhere in the Vale of York - or am I just hoping!

[Captain Shortwave]

I am expecting the first 30C of the year on Friday somewhere in the Vale of York - or am I just hoping!

probably reach 29.X.... again 

[nitro_deluxe]

probably reach 29.X.... again 

Hehe..can everyone stick their heating on this week end. Ta :)Next stop after 30? 32..34 take your pick.

[Milhouse]

Then on Saturday the attention switches to southern England with 32c on the GFS 12z.

 

 

Temperatures fall slightly on Sunday but for the second weekend in a row it looks perfect Summer weather for many.

 

Edited July 10, 2013 by Milhouse

[Weather Boy]

A quick comment about the col that some models, particularly the GFS has been showing.

 

I think in the current set up, with a virtually dead Atlantic influence, the col is likely to represent a continuation of the current weather, ie generally warm dry and sunny, with the potential exception of the NE, probably only NE Scotland, which is dangerously close to the trough.

 

However, cols do not usually persist for long as effectively they are an absence of any weather system and like nature abhorring a vacuum, weather systems like to fill the space!  Given thankfully few if any indications of the Scandi trough wanting to venture towards the shores (at least away from the far NE as stated) but rather to move away E/NE, it would seem to me that the logical solution would be for the Azores/Atlantic HP to re-build again to fill the gap.  There are strong indications, although definitely not agreement, that this will happen.  This may well turn into a 'UK high' again, as we are having this week.

 

Although I do hope for this, it's not hopecasting as it has a fair amount of support, as well (in my view) as a fair amount of logic.  I would therefore agree that High re-build is the 'form horse for 7-12 days hence.