Model Output Discussion 18z 28/07/13

[Weather Boy]

Rain for Sat looks even more persistant and heavy on the GFS 12Z compared to 6Z

 

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Hmmmmm I would even go as far to say that Sunday doesn't look that great either down South on the 12Z

 

Certainly agree, but slightly sceptical.  How often does the entirety of France and indeed most of the UK get a good soaking all in one go? 

 

That said, Saturday looking by far the worst day of the BH more or less everywhere.

[Captain Shortwave]

Warm rain. Lovely.

better than cold rain 

GFS and UKMO for Monday

 

 

Good agreement again

Again the GFS wants to build the Azores high in

Edited August 21, 2013 by Captain shortwave

[Captain Shortwave]

Weekend aside, GEM showing a great week ahead building the Azores high quickly

 

 

 

Corker of a run this is

 

 

 

If only 

Edited August 21, 2013 by Captain shortwave

[Man With Beard]

Weekend aside, GEM showing a great week ahead building the Azores high quickly

Corker of a run this is

If only

Looks like a nice north-easterly setting up, they'll love that in Great Yarmouth

[Frosty.]

WOW another super Gfs 12z run in high res which takes care of the rest of summer out to the end of august, a nice link up of the azores and scandi high as per the 6z and then the azores anticyclone strengthens it's position over the uk as next week goes on with a generally fine and warm week with light winds and lots of strong late august sunshine. This run would bring a nice bank holiday monday with high pressure taking control and temps in the low to mid 20's celsius, just about ideal conditions I would have thought following a more showery but warm few days, again with sunny periods between. Further into FI shows some beefed up atlantic lows trying to blast the azores high away from the uk but the south of the uk hangs on to a lot of fine and pleasant weather with some deterioration across the north of britain post T+240 hours which is very FI...it's looking like next week will bring a very nice closure to summer 2013.

[Frosty.]

The GEFS 12z mean is looking really good folks, even by sunday the high to the northeast and the azores link up and the shallow trough to the southeast clears away into mainland europe, next week would be just as good if not better than the gfs 12z op run, indeed, the mean looks like it would keep the fine and warm weather going into early september since the azores high looks very robust here, much less threat of atlantic depressions firing up as they rather inexplicably did on the op run, the 12z mean looks much more stable in setting up a more prolonged benign warm and settled spell for the last week of summer and at least the first week of autumn.

[Milhouse]

Indeed, the GEFS mean looks promising for a continuation of high pressure roughly centred to the south west of the UK until the end of August. ECM 12z out to Tuesday shows a progressively more settled bank holiday weekend with Tuesday seeing winds veering more northwesterly. High pressure not too far away though which may or may not force its way in as the run progresses.

 

[Man With Beard]

Is it going to be "northerner's revenge" this weekend? Looking at some of the charts, I fear the south may see a lot of cloud and rain this weekend, but the midlands and northern parts may get a surprisingly reasonable bank holiday.

[cheese]

Is it going to be "northerner's revenge" this weekend? Looking at some of the charts, I fear the south may see a lot of cloud and rain this weekend, but the midlands and northern parts may get a surprisingly reasonable bank holiday.

Good!

[J10]

To me the concentration of the heaviest rain is towards the South Eastern corner on Saturday, areas further North and West much drier and brighter.

 

 

But things can change very quickly and by no means are things set in stone.

Next weeks looks decent though with High Presure nudging in for the West/South West.

[Milhouse]

Indeed, the GEFS mean looks promising for a continuation of high pressure roughly centred to the south west of the UK until the end of August. ECM 12z out to Tuesday shows a progressively more settled bank holiday weekend with Tuesday seeing winds veering more northwesterly. High pressure not too far away though which may or may not force its way in as the run progresses.

 

 

The answer is a resounding yes it does

 

[picog]

To me the concentration of the heaviest rain is towards the South Eastern corner on Saturday, areas further North and West much drier and brighter.

 

Rmgfs96sum.gif

To me that looks like the central midlands is wettest on Saturday — with a generous dollop in the SE.

[Frosty.]

The Ecm 12z operational draws the PFJ (polar front jet) rather further south than the gfs & gefs mean which enables cooler oceanic air to penetrate across northern britain for a time and for unsettled and windier weather to sweep across the far north of the uk, this would be the worst case scenario since I expect the PFJ to remain further north than the ecm op run shows, however, there is long term gain from this flirtation with unsettled weather for the north because the azores/atlantic anticyclone does eventually build into the uk anyway and then across into the near continent and ends up being a euro high with very warm continental air feeding around it into the uk, so it's a fantastic last few frames to tonight's Ecm 12z despite the more borderline fine spell for most areas next week but in my opinion it's win win for us because if the PFJ stays further north, the azores high will build in sooner and stronger and if the ecm verified we would still end up heading into an end of summer heatwave, the 12z output is very encouraging this evening, T+240 hours is an absolute beauty with the 564 dam line incoming.. so the gfs is the safer option but the ecm has hotter potential later.

[syed2878]

wasn't we suppose to be in a start of a heatwave? So what went wrong?

[bluearmy]

Incredibly, we may have a handle on the w/end! Meanwhile, the ecm spreads show the depression well to the north of the uk day 8 op is much closer to scotland on the ensembles. I guess this is likely to become the threat to what looks increasingly like a decent spell and given what transpired this week, expect it to become the new trend on the nwp.

[Bradowl]

wasn't we suppose to be in a start of a heatwave? So what went wrong?

 

It will be here this time next week, this will be answer to same question this time next week as well. 

[DAVID SNOW]

wasn't we suppose to be in a start of a heatwave? So what went wrong?

 

Nothing, it was never real in the first place.

[Spurry]

wasn't we suppose to be in a start of a heatwave? So what went wrong?

 

To quote The Clash 'This is England', there is your answer

[Captain Shortwave]

The models keep dangling the carrot, all models want to built a ridge of high pressure around day 7 

ECM ens

 

Long-wave pattern looks ok again, not anything special but ok, it's just whether any shortwave features pop up to spoil the fun

Edited August 21, 2013 by Captain shortwave

[bluearmy]

The models keep dangling the carrot, all models want to built a significant ridge of high pressure around day 7 and hold it over the UK out to at least day 10.

ECM ens show this well

Long-wave pattern looks pretty good again, not anything special but ok, it's just whether any shortwave features pop up to spoil the fun

 

look at the day 8 spread captain  ............................

[bradymk]

The models keep dangling the carrot, all models want to built a significant ridge of high pressure around day 7 and hold it over the UK out to at least day 10.

ECM ens show this well

 

Long-wave pattern looks pretty good again, not anything special but ok, it's just whether any shortwave features pop up to spoil the fun

Someone help me out here, i remember this topic in the winter but can't 100% remember but if the long-wave pattern looks good, shortwaves should not be a problem as i am sure shortwaves do not just pop up anywhere, they are as a result of the longwave pattern? someone correct me if im wrong though. The models do show a much more settled week next week now than they did a few days ago (but not settled everywhere) and even the BH is looking much better than it did so im pretty happy tonight.

[Captain Shortwave]

look at the day 8 spread captain  ............................

To be honest I'm not expecting much beyond something similar to the mean which looks ok. Not going to expect more than a north/south split until the ens and anomaly charts show something more significant over the UK generally. Might edit my original post to erase the word significant

[damianslaw]

Its a messy outlook and quite an uncertain one, reliable timeframe is Saturday tops, how next week pans out will depend on the position of the shallow trough shortwave feature due to hit the country on Saturday.

 

This week has been an important lesson, this time last week all models were suggesting a strong build of heights from the azores by now, but as we have neared this time period, they have all backtracked and been caught out by developments to our NW... I said a few days ago, the azores high is much more likely to come under the influence of the atlantic low than the other way round at this time of year and the polar front jet looks to be inching its way back to its pre-July position.

 

My own thoughts are we are likely to see a couple of messy weeks ahead with a battle between the azores high and atlantic trough, with the atlantic winning out and the polar front jet heading back to its pre-July position by the middle of September.

[Biggin]

wasn't we suppose to be in a start of a heatwave? So what went wrong?

What went wrong ?? You havnt been paying attention.

[bradymk]

GFS 18z shows how a different position of the trough will affect how the AH builds in next week. As damianslaw says above, the position of saturdays shortwave will determine next week so until the position of that is sorted, next week will chop and change. GFS 18z shows the AH not building in as far due to a different position of saturdays feature and this results in the beginning of next week not being as warm or settled as quickly as 12z run.

Edited August 21, 2013 by bradythemole