Model Output Discussion 18z 28/07/13

[Buzzit]

+384 picture gallery and a massive fat euro high - I am expecting this for the first half of autumn so this would do quite nicely thanks - will be looking to see if we have a bit of change in the general pattern around 16th August as I feel the Azores will encroach a little before we get a full displacement to a Euro high dominated end of August and throughout September, around the same time as I expect the Atlantic Hurricane Season show a bit more life after the middle of this month as well. All conjecture at this point but we shall see...

 

[Tamara]

GFS and MetO do show agreement. However, the GEM 12z does not fully agree, and sees the pressure rise as being a brief flash in the pan. Like last night, all eyes on the ECM.

Its entirely hypothetical and academic as it is over a week away, but the GEM 12z maintains (mostly) something of a North to South split in the FI time period, with a flat pattern, but ridging not too far away from the south of the UK.

[Frosty.]

I'm even happier with the Gfs 12z than I was with the 6z, it's upgraded the warmth next week and ends with a very anticyclonic and increasingly warm further outlook beyond mid month, apart from that, it's very similar to the 6z with the coolest, wettest spells across the northwest of the uk (cumbria, n.ireland & west/nw scotland) but with some fine and warmer intervals too, but again it's towards the east & southeastern half of the uk where it looks generally on the warm side with lots of sunshine but with a few cloudier and cooler days with rain and showers, more so early in the period and then after the very warm and settled spell later next week, so yes it's a variable looking outlook but warmer, drier and sunnier the further south/se you are, hope it's right about next week, it looks like a nice spell of high pressure building in.

Edited August 7, 2013 by Frosty039

[cooling climate]

The storm bringing the cloud,snow and very low temperatures that I also posted about on

the snow and ice thread in the weather discussion and chat section looks (according to

the 12z GFS run today) looks like pre-empting a very early start to the very long and

bitterly cold Arctic winter.

The temperatures if the model run is anywhere correct stay very low throughout the

whole run across much of the Arctic basin making it one of the coldest and shortest melt

seasons across the high Arctic for a very long time. It would also be one of the earliest

starts to the Arctic winter for some considerable time.

[Milhouse]

Just need the ECM to leap onboard the idea of a pressure rise throughout next week. The GFS and UKMO like the idea (the GFS very much so) but the ECM this morning was ghastly in the latter stages. But for a month now the final 3 frames always seem to have been showing something very cool and wet.

The GEFS mean highlighs the possibility for high pressure to transfer east for a time drawing up some very warm air so the GFS 12z isnt without support.

 

[Man With Beard]

GFS ensemble mean at T144 quite close to GFS/UKMO op runs:

 

 

 

I think whoever is taking their hols in the UK next week is going to be fairly pleased. A settled and maybe increasingly warm week, until at least Thursday I'd guess but probably longer than that

[Milhouse]

The GEFS 12z mean is a slight improvement over the 6z with a stronger area of high pressure building across southern England throughout next week. So after a cool start to the week with temperatures in the high teens to low 20s it looks like it should warm up. Thursday sees 10c upper temperatures back into southern England

 

[TootyFruity]

GFS ensemble mean at T144 quite close to GFS/UKMO op runs:

I think whoever is taking their hols in the UK next week is going to be fairly pleased. A settled and maybe increasingly warm week, until at least Thursday I'd guess but probably longer than that

Oh thank god I hope so I was starting to sweat a little .....: )

[Milhouse]

Rain amounts do indeed look small but as always under a n/s split Scotland will be more prone to rain from passing fronts. Further south the GEFS mean indicates very little rain at all next week.

The warmth and increased humidity will be back next wednesday according to the GFS 12z.

 

[Milhouse]

The ECM so far has a cold front sweeping away the warmth on Sunday followed by a cool, breezy and showery day on Monday. The Azores high looks poised to move in, if it doesnt get flattened as per this mornings 0z.

 

[Man With Beard]

Oh thank god I hope so I was starting to sweat a little .....: )

 

... though this is the weather we're talking about, wouldn't count any chickens just yet!  

If we can get agreement from the ECM op and mean then I'd start to feel confident, though

[draztik]

 

ECM reluctant to build pressure, in contrast to GFS.

[TootyFruity]

ECM reluctant to build pressure, in contrast to GFS.

But am I right in saying that the ECM is on it's own as there's agreement between the GFS ens and op and the UKMO for the slight pressure rise next week ?

[draztik]

But am I right in saying that the ECM is on it's own as there's agreement between the GFS ens and op and the UKMO for the slight pressure rise next week ?

 

at 192, this is the output...

 

it looks like being a fairly unsettled week, if this comes to pass. This is in contrast to the GFS. I cant comment on the MetO as it only goes to 144.

[TootyFruity]

Also am I right to say that several times over the july heateave the GFS and UKMO agreed over high pressure but the ECM wasnt having any of it and kept showing a sort of breakdown by the Atlantic only to turn at the last minute and agree with the GFS ???

[Man With Beard]

so not quite a full house

Weather less settled by next Wednesday according to ECM. So can't be confident of a settled week just yet. In the last few weeks, low pressure systems from the west have tended to be corrected north rather than south as T0 approaches, so still plenty of time for this to change. 

[Summer Sun]

Also am I right to say that several times over the july heateave the GFS and UKMO agreed over high pressure but the ECM wasnt having any of it and kept showing a sort of breakdown by the Atlantic only to turn at the last minute and agree with the GFS ???

 

Best to wait for the ECM ensemble around 21:30 Tooty sometimes ECM can "go off on one" if the ensemble supports the Op then ECM may be right if the ensemble goes the settled route like GFS then the ECM Op could be an outlier

Edited August 7, 2013 by Summer Sun

[draztik]

Also am I right to say that several times over the july heateave the GFS and UKMO agreed over high pressure but the ECM wasnt having any of it and kept showing a sort of breakdown by the Atlantic only to turn at the last minute and agree with the GFS ???

 

I believe the GFS has very little support, and by looking at the anomaly charts, you kind of see why...

 

[Summer Sun]

Very dry on the London ensemble this evening which suggests to me pressure in the south will be fairly high for most of the month

 

 

Mind you its no August wash-out further north and west a stark contrast to previous years

 

[TootyFruity]

Tooty lol thanks summer sun .

I believe the GFS has very little support, and by looking at the anomaly charts, you kind of see why...

[TootyFruity]

So the anomaly charts are showing a trough influence is that right ? Wasn't there 1 anomaly chart this morning that wasn't agreeing with the others I think mushy posted it ! And John holmes does say that all 3 have to be in agreement . Sorry still learning x

[draztik]

Best to wait for the ECM ensemble around 21:30 Tooty sometimes ECM can "go off on one" if the ensemble supports the Op then ECM may be right if the ensemble goes the settled route like GFS then the ECM Op could be an outlier

the problem with that is the ecm has been the only model over the last few days to remain consistent with its output. It has shown unsettled conditions for the last 3 evenings. Whereas the gfs hasn't been able to make up its mind. The gfs may prove to be ultimately correct, but ill take consistency over erratic waves. Edited August 7, 2013 by draztik

[Frosty.]

There really isn't much difference in the overall pattern between the Ecm 12z and the gfs today, the models are showing an undulating pattern, rather like a wave motion with the azores/atlantic anticyclone building a ridge into the south and then a trough moving eastwards across the north and flattening the ridge before the next bump of high pressure ridging pushes east, so it's a mixed outlook ahead of us with warm and sunny spells, especially the further south you are, and also some cooler more average and unsettled spells, especially the further north you are, meaning, just like the gfs 06z and 12z showed, it's a very acceptable late summer pattern for the south of the uk, more mixed across central areas and generally unsettled across the far northwest, the gfs 12z op run is better for the second half of next week so fingers crossed the gfs is nearer the mark tonight, small adjustments north for the polar front jet will make next week look more summery for more of the uk, nothing is nailed yet.

[Methuselah]

From the models, it all looks like a very typical August pattern, to me?

[Man With Beard]

Also am I right to say that several times over the july heateave the GFS and UKMO agreed over high pressure but the ECM wasnt having any of it and kept showing a sort of breakdown by the Atlantic only to turn at the last minute and agree with the GFS ???

 

IIRC the GFS was the worst offender in trying to bring in a breakdown that failed.

 

In all honesty I think all the models have had 'wobblies' in the T120-T192 range recently - the UKMO seems adddicted to bringing the Atlantic in at T144 (today one of the few exceptions), ECM has been all over the place at times and the GFS has probably overstated HP rises since the heatwave broke. 

 

But when the GFS and ECM ensemble mean agree at T144/T168 then I think we're fairly close to the truth, so I totally agree with the post saying wait for the ECM mean at 9.30pm ish.