Model Output Discussion - 1st August 00z---------->

[Man With Beard]

The GEFS 12z mean shows increasing Azores high influence for most of the UK looking beyond the week ahead which I think is good news.

I note this as a consistent theme on GFS, GEFS and ECM ens. The downturn in the weather may just be for 3/4 days - and even then I don't foresee many washouts

[Frosty.]

Tbh mate, its been doing that all summer and so far has failed to deliver......

Agreed Rob, I'm just hoping the last few weeks of summer will deliver.

[knocker]

Similar evolution of the ECM ext anomalies this evening post the 18th.

http://www.tropicaltidbits.com/

 

[terrier]

Well very quiet in here at the moment. And looking at the output on the models it seems after this week we will be once again dominated by low pressure close to the UK. The gfs keeps it rather warm and more settled in the south for a time. Where as the North remains unsettled and rather cool into next week.

[summer blizzard]

Glory to those who want summer done with.

Too early to say summers over yet (GEM is summery) however the GFS and Euro take a good step closer.

[chionomaniac]

I see that the GFS is no different in the summer than it is in the winter, with a negatively tilted trough dominating on the 00Z whereas the 6Z has returned to the scenario with more energy over the top and the trough receding towards Iceland by day 10.

 

Take note all!

[linarite]

some rather nasty rainfall totals for NW England for the end of the week if the latest few GFS outputs are any guide.

[mushymanrob]

Glory to those who want summer done with.

Too early to say summers over yet (GEM is summery) however the GFS and Euro take a good step closer.

 

really?

after a poor summer (for heat) i wouldnt be surprised if we hang on to this current pattern of azores ridge trying to establish over the uk. whilst im ambivalent towards september warmth, it wouldnt suprise me one bit if we have another 6-7 weeks of warmth trying to establish via anticyclonic activity.

[Frosty.]

Only just seen the GEM 00z, what a BEAUTY!

[knocker]

I see that the GFS is no different in the summer than it is in the winter, with a negatively tilted trough dominating on the 00Z whereas the 6Z has returned to the scenario with more energy over the top and the trough receding towards Iceland by day 10.

 

Take note all!

 

I would be grateful for some clarification chio. Running through the 06z 500mb chart the trough still appears negative to me through days 4-7, possibly 8. And would I be correct in assuming  that we must take note because of the association of increased instability and cold air advection with a negative trough.

[mountain shadow]

really?

814day.03.gif

Rtavn2402.gif

after a poor summer (for heat) i wouldnt be surprised if we hang on to this current pattern of azores ridge trying to establish over the uk. whilst im ambivalent towards september warmth, it wouldnt suprise me one bit if we have another 6-7 weeks of warmth trying to establish via anticyclonic activity.

What do you mean by another 6-7 weeks of warmth?, that implies we have just had 6-7 weeks of warmth.

 

Anyhow the over overnight ECM and the latest 6z GFS are a continuation of what this "Summer" has been throughout. A dominant Westerly driven pattern, drier in the South and East, wetter in the North and West with average to below average temps for all.

 

Some large rain totals for central and North Western England later this week.

[Polar Maritime]

What do you mean by another 6-7 weeks of warmth?, that implies we have just had 6-7 weeks of warmth.

 

Well Mushy did say 'Warmth trying to establish' Which has pretty much been the case so far.

[chionomaniac]

I would be grateful for some clarification chio. Running through the 06z 500mb chart the trough still appears negative to me through days 4-7, possibly 8. And would I be correct in assuming  that we must take note because of the association of increased instability and cold air advection with a negative trough.

It was more a comment on the runs by day 10 - the 6Z has a warmer SWesterly over Scotland with receding of the trough back towards Iceland as compared to the 00Z - the old default GFS coming to the fore! And I am happier with the 06Z run here!

[Frosty.]

I am happier with the 06Z run here!

Me too!

[Frosty.]

The Gfs 12z saves the best until last with high pressure building in strongly for the last days of summer with increasingly very warm and settled conditions. As for next week, it's not as nice as the 6z because there is a persistent trough to the northwest which is too close to allow any sort of anticyclonic spell to develop next week but it's no washout either, there is some warm and fine weather next week, especially for the south and east but with bands of rain alternating with sunshine and showers too, most of the wind and rain is further northwest so it's swings and roundabouts, what we lose in the shorter term we gain further ahead and the last week or so of August looks fantastic on this run.

Edited August 10, 2015 by Frosty.

[stodge]

Afternoon all

 

Strange, I must be looking at a completely different Op run to Frosty or perhaps I don't have his rose-tinted glasses but overall it's an uninspiring spell upcoming. The European LP plagues the south through to the weekend before pulling away and drawing in a weak NW'ly flow.

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015081012/gfs-0-84.png?12

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015081012/gfs-0-114.png?12

 

Into next week and the Azores HP doesn't make much early headway and the Atlantic LP very much in charge but the SE shouldn't do too badly from this:

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015081012/gfs-0-192.png?12

 

Moving into low-res and after another cool NW'ly, the Azores HP finally makes its move:

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015081012/gfs-0-222.png?12

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015081012/gfs-0-300.png?12

 

It's a strong ridge and should produce 4-5 decent days for the south though the far NW remains susceptible to Atlantic incursions. The problem is as the detached Azores HP cell heads east, the gap opens up for the trough to fill in and at the very end of the run it turns unsettled once more:

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015081012/gfs-0-384.png?12

 

So it's a week of unsettled and at best non-descript weather before the possibility of the Azores HP moving in, albeit still in low-res.

 

Nothing too inspiring then from the GFS evening output.

[Frosty.]

Strange, I must be looking at a completely different Op run to Frosty or perhaps I don't have his rose-tinted glasses

Don't get sarcastic! I reasonably described what the gfs 12z shows, nothing rose tinted about it, just look at the charts I posted for the last days of August, they look very warm and summery and I hope we get a nice end to the meteorological summer. Edited August 10, 2015 by Frosty.

[knocker]

Just an observation.

Much attention has been given to the Atlantic SST anomaly. Well moving south another July mark: SSTs in the tropical Atlc/Carib compared to global tropics were the coolest on record. What with El Nino and this one can understand this years hurricane forecast.

Edited August 10, 2015 by knocker

[knocker]

Tonight's run of the GEFS anomalies epitomizes the summer for me if we are considering the whole of the UK. Two things regarding the summer stand out. The Scandinavian ridge and the interplay between the upper trough and the warmer air of the Azores HP which has led to the divisive N/S divide of weather over the UK. On a number of occasions it's look set for ridging from the SW to gain control only to be zapped by further intrusion of the colder air.

So now to tonight's run.

 

On Monday the trough firmly in charge bringing unsettled cooler weather to most parts but after this it starts withdrawing the trough NW to Iceland allowing the Azores ridge to build and by Mon/Tues things looking with fine warmer weather for all. Previously this was looking good from now until the end of the run but no by the 21st the trough is spreading it's wings again.

 

But we are looking a fortnight hence here so in general I'm going to say that after Monday the next week will be more settled and warmer for all with perhaps the odd incursion of cooler air in the Scotland.

http://www.tropicaltidbits.com/

Edited August 10, 2015 by knocker

[Frosty.]

This evening's Ecm 12z shows a fine and warm day tomorrow for most of the UK with high pressure in control but it doesn't last, though Thursday it becomes more humid in the south with pressure falling and an increasing chance of thundery downpours. We then have an unsettled and cooler spell which lasts into early next week, always worst across nw britain with a trough to the northwest of the UK which eventually fills and gets pushed away north and becomes absorbed into the main low pressure complex around iceland as pressure begins to rise from the southwest. From there it's a rapidly improving picture with high pressure building in across the south with increasingly warmer and settled conditions, especially across the southern half of the UK.

Edited August 10, 2015 by Frosty.

[chionomaniac]

What is noticeable about the summer so far, is hardly a Scandi Ridge when one looks at the 500hPa anomaly chart. In fact the opposite is true.

 

The thing that epitomises the summer so far is the omnipresent north Atlantic trough which has led to a north/ south divide, with the further north being closer to the trough, and hence more unsettled. Down here, near the south coast, summer has been quite pleasant with many days of dry summer weather experienced and this is borne out by the chart below.

 

 

The extended anomaly charts have continually suggested that the Azores ridge will push the trough further north, but actually the Atlantic trough has recycled and this has never really occurred for any length of time. So why has this situation existed? I think that this is more difficult to answer. It is hardly as if we can point at the MJO which has not stagnated in any particular phase - in fact I see an almost perfect orthodox orbit this summer which has only recently stagnated.

 

 

I do think that the answer lies somewhere with the developing EL NIno, Arctic High Pressure - holding the Atlantic trough further south and Atlantic SST's

 

 

[seaside 60]

What is noticeable about the summer so far, is hardly a Scandi Ridge when one looks at the 500hPa anomaly chart. In fact the opposite is true.

 

The thing that epitomises the summer so far is the omnipresent north Atlantic trough which has led to a north/ south divide, with the further north being closer to the trough, and hence more unsettled. Down here, near the south coast, summer has been quite pleasant with many days of dry summer weather experienced and this is borne out by the chart below.

 

compday.TtiLU0xs5S.gif

 

The extended anomaly charts have continually suggested that the Azores ridge will push the trough further north, but actually the Atlantic trough has recycled and this has never really occurred for any length of time. So why has this situation existed? I think that this is more difficult to answer. It is hardly as if we can point at the MJO which has not stagnated in any particular phase - in fact I see an almost perfect orthodox orbit this summer which has only recently stagnated.

 

phase.Last90days.gif

 

I do think that the answer lies somewhere with the developing EL NIno, Arctic High Pressure - holding the Atlantic trough further south and Atlantic SST's

Would you be brave enough to estimate if this will all change towards autumn.

It seems to me that this Azores ridge has been the main/or a fact of controller since Jan this year, its never appeared to have moved much.

[knocker]

Tonight's NOAA look as if they are agreeing with what the ext GEFS hinted at.

 

[summer blizzard]

Euro is poor days 5-8 before pressure rebuilds..

 

JMA is poor days 5-8.

 

GEM is poor days 5-10.

 

GFS is poor days 5-9.

 

..

 

Any rebuild from the Azores aint happening before day 8.

[knocker]

And so it goes on

 

Michael Ventrice â€@MJVentrice 2h2 hours ago

Wave breaking o/ North Pacific causing havoc in the models. Today's GFS versus ECMWF op forecast for next Wednesday

 

Edited August 10, 2015 by knocker