Model Output Discussion - 1st July Onwards 18z--->

[Summer Sun]

GFS shows the chance of something warmer next weekend with temperatures back into the 20's for some parts of Scotland though its a different story sadly with temps struggling to make it into the teens

 

These are the minimum temps

 

 

And the maximum temps

 

 

It doesn't look overly wet for the bulk of England a different story in the far west later in the weekend though as a band of rain moves in from the Atlantic weakening the further east it goes

 

[bluearmy]

Would say the ops beginning to trend a different path to recent ens guidance. not unknown for this to verify although the ens generally hold sway.

[Gibby]

The updated ECM 10 Day Mean Chart from last night is very similar. I know these charts can be a bit deceiving made up all types of options between the members but it does reflect changes between last night's pack to this morning's remain pretty small.

 

http://www.wetterzentrale.de/pics/Reem2401.gif

Edited July 26, 2015 by Gibby

[Tamara]

Some inclement trough led synoptics and an (apparent) refusal of the models to back an anticipated upturn in weather patterns for the UK into August seems to have precipitated another seasonal round of spurious statements in certain threads (not necessarily this thread at all) about the value, accuracy and point altogether of looking to tropical and extra tropical drivers in medium and extended timeframe model outlooks and forecasts (N.B : not LRF's as I have seen quoted!) 

 

The ocean/atmosphere "harmony"  in terms of El Nino and associated breakthrough in upturn in Atmospheric Angular Momentum which precipitated pattern changes increasingly through the second half of June were well documented and verified accordingly, and do not need any repeating in detail here. A warming trend was suggested away from the homogenously uniform cool UK Spring (but not sustained countrywide heat)

 

This is precisely what happened in the closing period of June and early part of July, bringing a record July temperature on July 1 with it, irrespective of the fact that further NW it was (alas) a brief encounter.

 

Some added perspective on this though at the end of the post.

 

This trend was picked up relatively late in most all (reliable) upper anomaly charts and was an instance which served to prove that all NWP can be susceptible to not anticipating large scale atmospheric/ocean signals - especially when a long term de-coupling of ocean and atmospheric signals is coming to an end. The shoal of fish changing direction in mid stream analogy was used at the time to describe how the model data might start to deal with the Atlantic upper trough at the time and that the propensity for dominating polar maritime airstreams would change

 

An overall illustration that ocean/atmosphere coupling (or not as the case has been for some long period of time before this summer) is a very useful first port of call in deciding how synoptic models might evolve. The worth and value of these processes for gaining clues in medium and longer terms forecasting in this respect cannot ever be 100% bullet proof. What is much harder to do is to decide whether NWP is in harmony and is jiving with ocean/atmosphere signals.

 

This is not easy obviously even for the professionals - after all, atmospheric tendency is in a state of constant flux and Mother Nature cannot accommodate a vacuum. Its a constant "compensation" process of atmospheric momentum transport from one part of the globe to another, and trying to keep tabs on these complex processes, and deciphering speed of changes will cause problems for the most experienced technical professional forecaster, let alone anyone on amateur weather forums

 

On another interesting subject raised recently on this thread, the stalled and sharpened Atlantic trough and amplified downstream ridge at the end of June and the start of July clearly is one very good illustration that a cold water pool anomaly to the west of us is not in itself an obstacle at all to achieving very warm synoptics in this part of NW Europe. We looked then, as always, to the much wider hemisphere atmospheric circulation for answers as to how these synoptics evolved, and what occurred upstream, to make them happen

The answer to the way out of the NW Europe trough led pattern remains exactly the same as the one discussed repeatedly often in these threads previously (and in accordance with the recent suggestions of the type of improvement muted in METO extended updates for the new month).

Simply because they haven't been apparent in NWP or upper height anomaly forecasts doesn't mean those answers and derived expectations are wrong and that tropical (MJO) and extratropical (GWO) drivers and indicators somehow "don't work".  These difficulties lie in the deciphering processes as mentioned above.

 

In this respect, the watching brief that has persisted in looking for more obvious signs that the advancement of the next tropical wave train circulation, might be starting to show clearer evolvement to another rise in AAM is starting to filter through - the rise that will kick something of a re-arranging of the deckchairs to the UK/NW Europe trough led pattern which firmly features this week.

 

As was the case in June, it was tropical convection advancement that increased AAM tendency, initiating westerly winds across the tropics, propagating rossby wave activity northwards and eastwards to mid latitudes and leading to higher pressure over NW Europe and the UK in place of an upper trough.

 

ECM picking up on this tropical development orbit as we head into August with the trend to pick up amplitude towards the maritimes observed

 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/ECMF_phase_51m_small.gif

 

Forthcoming Global Wind Oscillation forecasts in the days ahead will, accordingly, be interesting to observe

 

NWP fluctuates, as ever, in accordance with the omnipresent state of flux of the atmosphere - but this signal gaining traction will consolidate the trend for the trough to back away and promote downstream ridging once again for NW Europe as AAM tendency rises

 

This doesn't guarantee a UK wide warm anticyclone, and the prospect of something of a NW/SE split remains. However, with a coupled El Nino atmosphere/ocean signal -  suspicions that have persisted attached to a surpressed GWO regime and sustained trough over the UK and NW Europe for an extended period might be starting to raise their head more obviously as the modelling starts sniffing out a different orientation and subtle backing away NW of the upper trough that will dominate the weather for certain in the shorter to medium term

It will take very little in real terms to change present (face value) negative perceptions once more, so a sense of perspective about what is left of this changeable summer is sensible in my opinion

 

The following temperature anomaly chart, "borrowed" from the WSI site, for the first two thirds of July rather shows the bigger picture in terms of the UK and European pattern - with SE parts of the UK on the periphery of the great heat over much of mainland Europe.

 

Looking at this as a macro pattern perspective (and less of an IMBY micro pattern) it can be seen how knife edge much greater parts of the UK has been to a much more appealing summer pattern which would have changed the (understandably) negative perceptions of many more members who have lived further NW outside of the periphery of this warmth/heat

 

https://pbs.twimg.com/media/CKhGv68WcAAS2kI.png

Edited July 26, 2015 by Tamara

[bluearmy]

The updated ECM 10 Day Mean Chart from last night is very similar. I know these charts can be a bit deceiving made up all types of options between the members but it does reflect changes between last night's pack to this morning's remain pretty small.

http://www.wetterzentrale.de/pics/Reem2401.gif

The spread brings a discreet system across the Midlands days 8 through 9. This ECM suite looks like a split option upcoming and I suspect a warmer set of London ens appearing at midday.

Day 8 / Day 10

.

Edited July 26, 2015 by bluearmy

[Nouska]

For Reading, the deterministic is right at the top of the range at the end of the run.

 

http://i.imgur.com/XfGJeWD.png

 

Freebie for today is Iceland.  http://old.ecmwf.int/products/d/sampler/epsgrams/europe/page.html

[BlueHedgehog074]

Only just noticed it, but ECMWF's new website looks pretty sick! http://www.ecmwf.int/ 

 

 

Older version: http://old.ecmwf.int/

 

 

 

 

 

[Stormyking]

12z now rolling out, hopefully it carries on the same theme with some potential heat building after this unsettled period. Tonight can already see winds picking up more along with a showery theme

[Milhouse]

As I mentioned ...north north west winds midweek...suppressed temps.....models showing a high of 20 Saturday....at the height of Summer....Some of us mentioned this but were shot down ....ECM gfs jma all suggest supressed temps way into Aug...no heat or so called plumes predicted

 

Way too early to suggest suppressed temperatures well into August. Given the GFS 12z once again throws in a nice weekend. 22c on Saturday, 24c on Sunday. Southerly winds pushing up heat from the south on Monday. Think it begins with a 'P' but not allowed to mention it on here lol.

 

[mushymanrob]

Way too early to suggest suppressed temperatures well into August. Given the GFS 12z once again throws in a nice weekend. 22c on Saturday, 24c on Sunday. Southerly winds pushing up heat from the south on Monday. Think it begins with a 'P' but not allowed to mention it on here lol.

 

Very nice eye candy, but without anomaly support such a large, strong, high just isnt going to happen.

Of course the anomaly charts could change, and hopefully they will, but until they do the chances of such a run like the 12z gfs suggests must be non existent.

[Milhouse]

Not as warm as the GFS 12z but the GEM this evening also lending support

 

[summer blizzard]

UKMO with a different solution at day 6.. The 1020mb isotherm not looking like it will develop quickly.

 

[bluearmy]

So far the 12z ops continue the themes of their previous run. Awaiting the ecm to see if the possible return of summer is gathering pace.

[knocker]

The GEFs anomalies tonight are a bit of a tease.

 

On Monday/Tuesday there is ridging nearer to the east and the upper low/trough is orientated SE. This would support the surface analysis of the ops allowing incursions of warmer air from the SE/S certainly into the S/SE of the UK. This doesn't turn out to be a sustained scenario as we travel into the ext period with the weak trough situated north and running south and a more zonal flow back in place probably allowing more influence from the Azores and average temps. This still seems to my uneducated eye a pretty finely balanced scenario  but I've a gut feeling that better times might well be on the way.

http://www.tropicaltidbits.com/

Edited July 26, 2015 by knocker

[stodge]

Evening all

 

I'm not sure about themes - all I see is uncertainty and plenty of it:

 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/new.nao_index_ensm.html

 

The strong trend for the NAO to go back neutral/positive has been stopped and we now have wide scatter as early as next weekend. Just in passing, the AO has been negative for some time and seems set to continue in that vein:

 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao.sprd2.gif

 

So to the evening OP runs:

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015072612/gfs-0-144.png?12

 

To be honest, this is almost a west-based negative NAO chart with the trough digging a long way south and strong blocking over Greenland but the orientation of the block isn't quite there but this wouldn't be a bad chart for the south under an albeit weakish ridge.

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015072612/gfs-0-240.png?12

 

As the strong LP spirals north, it allows HP to be drawn up from the south as it seems to pull the jet up behind it. Another settled chart  though perhaps not with the heat some would like but this is very reasonable.

 

Strangely, the real interest is across the Pole as a strong area of LP develops over the Bering Strait, crosses the Pole and settles over Greenland lowering the heights so that by the end of the OP run, there's more than a hint of a more "traditional" pattern emerging with the Azores HP migrating north and ridging NE so those arguing for better weather going into August look to have something on their side albeit this is all still a way off.

 

http://modeles.meteociel.fr/modeles/gem/runs/2015072612/gem-0-180.png?12

 

GEM has a different evolution with the LP due to pass to the west and north-west not heading north but instead heading NW and rotating around to the south-west of Iceland while heights are maintained over Greenland.

Edited July 26, 2015 by stodge

[Milhouse]

UKMO on its own tonight in not bringing in the Azores ridge and a subsequent rise in temperature.

[Summer Sun]

Whilst not totally settled early August is now looking that bit warmer

 

 

A mixed week this week with temps well below normal at times and some chilly nights around mid week in rural areas but all is not lost yet for some heat

[ANYWEATHER]

Evening, A long way off but the gfs and ecm develop a deep low during this coming weekend, worth keeping an eye on...

[Man With Beard]

Like some others, I'm actually feeling much more positive about the start of august tonight. Regardless of the lows spinning towards us, both GFS and ECM are showing consistency in lifting the upper trough further and further to our north between D5 and D10. Not perfect at all, and rather fragile, but "bank".

[summer blizzard]

Euro brings a N-S split from day 8 as the pattern essentially stalls with neither the low nor high in control.

 

[Weather Boy]

Evening, A long way off but the gfs and ecm develop a deep low during this coming weekend, worth keeping an eye on...

The tendency has been to move it north and make it transient though. Fine weather both before and after those charts. Indeed I think tHe ECM chart that you have posted would I think give a fine day for England south of roughly Yorkshire.

[mushymanrob]

Very nice eye candy, but without anomaly support such a large, strong, high just isnt going to happen.

Of course the anomaly charts could change, and hopefully they will, but until they do the chances of such a run like the 12z gfs suggests must be non existent.

Whilst the gfs 12z was over developing fi high pressure, the latest anomaly charts do allow pressure rise over europe. So maybe the ecm at 240 wont be far off what we might get. Ok for you in the southeast not so clever for you in the northwest.

[ANYWEATHER]

The tendency has been to move it north and make it transient though. Fine weather both before and after those charts. Indeed I think tHe ECM chart that you have posted would I think give a fine day for England south of roughly Yorkshire.

 A long time of weather between here and then,,,,,

Edited July 26, 2015 by Polar Maritime
To move discussion on.

[Weather Boy]

Euro brings a N-S split from day 8 as the pattern essentially stalls with neither the low nor high in control.

 

Yes at that range the trend is your friend and looking at SS's charts there seems to be some agreement on a deep low glancing N Ireland and Nw Scotland and then moving north. By the time it reaches north of Iceland its influence will be all but gone save for the northern Isles. If that verifies you'd imagine that HP would fill the void from the west.

This post sounds somewhat like hopecasting as Given recent poor weather and more to deal with this week but it's supported by GP, Tamara and most importantly the Met Office who continue to be bullish as to a fine August. Doommongers beware. We are due a good August. I do hope I'm right! 

Edited July 26, 2015 by Polar Maritime
To remove duplicate post.

[Weather Boy]

A long time of weather between here and then,,,,,

Yes, a pretty poor outlook for pretty much the whole country in shortish term but from Wednesday a somewhat improving picture. Sunday looking to be a bit of a blip, and probably a more than a blip for the North and west. Early signs have been consistent for the improvement to continue thereafter, except for last Friday's models that wanted to keep the dartboards rolling in. Fortunately that seems no longer the case. They could change back but the background signals suggest otherwise.

Edited July 26, 2015 by Polar Maritime
To move discussion on.