Model Output Discussions 12z 01/06/2017

[draztik]

22 minutes ago, northwestsnow said:

Yup, absolutely nothing is straightforwards for summer heat lovers or winter cold lovers.

GFS is another poor run in the reliable ..if its not a god damn trough moving in from the North west its a bloody trough sticking around the north sea like a bad smell.

Just roll on sept when there will no doubt be some warmth, im afraid its fast turning into another disgusting sorry excuse for a summer up here!

Bit of an over reaction? What do you want ? 45c? People are dying in Europe. We are seeing standard fare, no more no less. Less grumbling! The weather won't reward a grumbledor! 

Little in the way of heat on tonight's GFS, 11-16 Aug shows below average temps, which is the story throughout its run. 

[mushymanrob]

56 minutes ago, Frosty. said:

Feel free to disagree old chum, I wasn't even talking about the 6z operational, I was talking about the 6z mean which is increasingly settled and warm with the azores high becoming dominant! ..now I'm not saying for a minute that it will verify but I think there is cause for optimism, at least for southern uk as we go towards / during the  mid month period.

surely the mean will downgrade though, thats 2 disastrous runs now off the gfs, the mean have to downgrade.

if its any consolation, the anomaly charts dont allow for a trough dominated week, but then again these changes are happening before their timescale starts..

[BlueHedgehog074]

I think if it was Winter, the GFS would have been a great run for some cold and possibly wintry conditions with it's stubborn trough to the North-East of the UK drawing down some chilly North-Westerly/Northerly and North-Easterly winds. Even though both the GFS 06Z and the 12Z show the Low Pressure system wanting to stick to the East of us like glue next week, I do personally feel its being too aggressive with the Eastern UK troughing. Not to mention I feel it's slightly over-doing the amplification of the High in the Atlantic (which would kinda help to hold up the troughing to our East/North-East). The likes of the ECMWF and UKMO just seem more realistic with the Atlantic/Azores High Pressure system fairly quickly getting flattened towards mid to late next week with the High getting drawn over Southern UK

Could be wrong and it's possible it might be a new trend (even then, the GFS does eventually clear away the Low Pressure to our East), but have seen scenarios in the past (admittedly most particularly during Winter) where the models have over-estimated the stubbornness of any troughing to our East and under-estimating the strength of the Jet Stream powering through blocking and amplified Highs in the Atlantic 

For now, I'm remaining weary of the GFS's outlook for next week. Not because it's not showing what I want, but because of the above reasons. It would be one of those cases, however, that the West or South-West of the UK would generally see the best of any drier, brighter, conditions while the East would see more in the way of wetter conditions

[blizzard81]

The last 4 or 5 years have been like groundhog day. Mild winters. Cool, wet summers, nice September and October warm spells. Forecasters should find it easier to make seasonal forecasts these days as every year is virtually the same. 

[Frosty.]

All things considered, the GEFS 12z mean becomes very acceptable considering the changeable / unsettled pattern we are in right now...gradually turning increasingly settled and warm, much like the earlier 6z mean with high pressure becoming more influential as time goes by, especially across southern uk..

Edited August 4, 2017 by Frosty.

[mb018538]

Sadly ECM follows the same sort of path too...not settled at all, and not much of an improvement if we're being honest. Let's hope the 00z picks up and is more like today's 00z, which looked nice.

For what it's worth, the 12z GFS was a big wet and cool outlier.

[ANYWEATHER]

History will tell you that our weather is always unpredictable and just when you think you've spotted a trend in our weather ,it then drops the trend 

[blizzard81]

The UK seems to be a magnet to those lows to the north west this summer. We just can't shake them off. 

[northwestsnow]

1 hour ago, draztik said:

Bit of an over reaction? What do you want ? 45c? People are dying in Europe. We are seeing standard fare, no more no less. Less grumbling! The weather won't reward a grumbledor! 

Little in the way of heat on tonight's GFS, 11-16 Aug shows below average temps, which is the story throughout its run. 

Over reaction? Its been another poor summer up here im afraid and patience is wearing a bit thin now..im not entirely sure what people dying in Europe has got to do with my post, It goes without saying nobody wants people to die from the weather,,in any shape or form but the truth is be it in summer (heat)or winter (cold) , people do lose their lives..

Back to the models and ECM has joined in with making more of the Atlantic - at this rate it will be Sept before we get  stable spell of high pressure! In fairness the south looks ok next week away from the relentless troughs/dross that has plauged the north sice,late June..

[Frosty.]

Actually the Ecm 12z looks decent for the south later next week with a spell of largely fine and warmer weather thanks to a ridge of high pressure so at least it would be better than we have been used to in recent / current times, the north improves for a time later next week as a ridge topples in from the NW before it becomes more changeable again up north and we revert to a more typical north-south split..but then another push from the azores high at T+240 to end the run on a potentially more promising note.

[knocker]

I have to say things are getting a tad complicated next week with the ecm.

Monday 12z has the upper trough. centred just south of Iceland running, south to Coruna which on the surface has a showery westerly over Britain but more to the point forms a general low pressure area over western Europe which includes the Iberian low.

In the next 36 hours outbreaks of thundery activity run east from the France/Spain border then north east as a more organized low develops to be centred northern Germany by 00 Weds. (I seem to remember the models playing around with this idea two or three days ago)

The low continues to intensify through Wednesday and by 18z is over southern Norway with northerly gales in the North Sea and the weather not too shabby along the east coast of Britain either. For the next 30 hours the low swans around the eastern North Sea as the Azores ridges north east past Scotland making a connection to the high pressure in Eastern Europe which is also amplifying and it is the dual amplification of these two that has initiated the mayhem in western Europe with the upper trough neatly sandwiched, and in particular the North Sea.

By 12z Friday the low is at last exiting the North Sea but another trough has arrived and is impacting N. Ireland and western Scotland. By the end of the weekend it gets on with the serious business of the Azores ridging in from the south west.

[draztik]

25 minutes ago, northwestsnow said:

 

Edited August 4, 2017 by draztik

[northwestsnow]

7 minutes ago, draztik said:

This should be in the moan thread, as it's yet another moan. 

 

Edited August 4, 2017 by northwestsnow

[Frosty.]

6 hours ago, Mokidugway said:

Ever the optimist Karl,best way to be 

Cheers, yes, to me, going by the Gefs / Ecm mean charts I've been posting a lot in recent times, it still looks like at least southern uk can look forward to some welcome respite from the changeable / unsettled pattern we have become locked into. Towards the end of next week and into week 2 i'm seeing Azores ridging influencing southern uk with warmer and more settled conditions for a change!

Edited August 4, 2017 by Frosty.

[Matthew.]

That Azores high is being flattened way too quickly for any proper settled conditions. All in all though very normal late summer weather really. Think some are after the extremes thinking their normal. September sees the high migrating NE so this is always favourite for settled. Apparently September 10th is national high pressure day

[mb018538]

The problem could be that the strong ridge to the east is going to be too powerful for the low pressure to effectively clear away and allow the high to build across the Uak?

[summer blizzard]

50 minutes ago, blizzard81 said:

The UK seems to be a magnet to those lows to the north west this summer. We just can't shake them off. 

The basic reasoning for that is that despite moving towards El Nino the La Nina imprint from winter (waning as we entered early summer) has persisted and indeed as we reached mid July it returned with some vengance. 

Although the signal did weaken (the lagged effect being why i expected something more seasonal around the 10th) we can now see that the stronger trades are arguably more widespread in the coming forecast and essentially causing any MJO wave that wants to get going to hit a brick wall. 

Hurricanes can change the pattern (for better or worse) but in terms of a background signal i don't think we have an especially good one given that logically you'd imagine stronger widespread enhanced trades will cause lower GLAAM and a flatter jet stream. 

[karyo]

The 18z deepens the North Sea low further and gives an impressively strong northerly on Wed and Thu next week!

[blizzard81]

2 hours ago, summer blizzard said:

The basic reasoning for that is that despite moving towards El Nino the La Nina imprint from winter (waning as we entered early summer) has persisted and indeed as we reached mid July it returned with some vengance. 

Although the signal did weaken (the lagged effect being why i expected something more seasonal around the 10th) we can now see that the stronger trades are arguably more widespread in the coming forecast and essentially causing any MJO wave that wants to get going to hit a brick wall. 

Hurricanes can change the pattern (for better or worse) but in terms of a background signal i don't think we have an especially good one given that logically you'd imagine stronger widespread enhanced trades will cause lower GLAAM and a flatter jet stream. 

Not good news for the coming winter I assume?

[blizzard81]

27 minutes ago, karyo said:

The 18z deepens the North Sea low further and gives an impressively strong northerly on Wed and Thu next week!

The story of high summer. North sea trough alternating with cool, very showery north westerly airstream. Worst nightmare for UK summer. Just had 2 weeks holiday from work and the weather has been absolute pants! 

Edited August 4, 2017 by blizzard81

[knocker]

Last evening's interesting developments of the transient amplification and the North Sea low are outside the remit of the early period anomalies but obviously this will have some impact on this analysis and the upcoming question of the Azores HP influence in which all of us have a vested interest. Unfortunately this  isn't answered with last night's anomalies with some quite significant differences particularly regarding the EPS So best one can say is it's not looking unfavorable and then cop out and wait and see what today brings forth.

On to this morning.

Monday 00z sees the next low over the Hebrides with fronts across the country  It is from here that the amplification begins in earnest with the Azores ridging strongly in the Atlantic and reciprocated by the HP to the east which disrupts the jet and creates a strong meridional flow and 'traps' the trough over Britain and the North Sea.

The developments on the surface are very much like I described yesterday evening vis the ecm run. Tuesday at 18z sees a disturbance developing on the France/Spain border and tracking north east. Twelve hours later this has formed a low 1002mb over Denmark, all of which takes the UK from a very slack pressure area to a showery northerly and note the Azores ridging a fair way NE

By 00z Thursday it has become quite an intense little feature south west of Norway and over the next 24 hours it meanders slowly south, all of which could just impact the east coast whilst the ridge moves in from the south west. The latter duly comes under pressure from the next trough arriving from the NW but by the weekend we eventually arrive at the scenario indicated by the anomalies and the Azores taking closer order. But of course we are still left with main question which is of course how will this N/S work out and the answer as always will have to wait until the det. runs sort out the detail.

So all in al a cool showery start to the week giving way to quieter and more settle conditions as most of the action takes place to the east.

Edited August 5, 2017 by knocker

[Frosty.]

Once we get past the cool windy unsettled dross on wednesday the Gfs 00z shows some decent august weather at times, especially further s / e / se with generally higher pressure, warm sunshine and lighter winds.

Edited August 5, 2017 by Frosty.

[knocker]

The ecm very similar to the gfs. A belt of rain running east effecting N. Wales northwards Sunday evening giving way toa light wind and showery routine Mon/Tues/ before the wind veering northerly on Wednesday. and then the Azores ridging in on Thursday as the low in the North Sea moves away east and thus drier and more settled conditions. But by Friday this is suppressed by a large trough area that has tracked east to be east of Iceland and thus the UK in quite a strong westerly with the showers concentrated in the north.

Edited August 5, 2017 by knocker

[northwestsnow]

00z runs showing a real battle between the relentless troughs to the North west and the Azores high desperately trying to ridge in.

A north south split looks likely ..the question is where the boundary sets up, for NI/ Scotland it looks awful, for those further south into southern England it looks like a general improvement is imminent..

For those in between the 2 mentioned areas its a case of waiting and hoping.

[Frosty.]

Looking at the Ecm 00z, as with the Gfs 00z, south is best after the cool windy unsettled midweek dross with a welcome ridge of high pressure extending across the south with warm spells of sunshine, another surge from the Azores high / ridge day 9 / 10.

Edited August 5, 2017 by Frosty.