Model Output Discussions 12z 03/05/2016

[summer blizzard]

38 minutes ago, Matthew Wilson said:

I better ring the BBC up and tell them to get that 21:55 update changed Wonderful charts tonight!

I suspect the GFS and Euro are right but in the interest of balance they may be thinking something like the GEM..

[Frosty.]

Interesting Ecm 12z ensemble mean at T+240 hours, look where the polar front jet is.. Greenland!

Now let's hope the mean moves towards tonights operational and we really will be in business!

[Matthew.]

8 minutes ago, summer blizzard said:

I suspect the GFS and Euro are right but in the interest of balance they may be thinking something like the GEM..

Yes it seems that way. Just watched the BBC update and the main principle was 'we think'

Edited June 12, 2016 by Matthew Wilson

[knocker]

Not sure I agree with your position of the jet at t240 Frosty old bean it's blowing straight across the Atlantic dipping SE just west of Ireland.

Anyway no sign of any excessive heat or build up of HP on the EPS an NOAA anomalies tonight.

The 6-10 both have slight ridging from the SW and a trough to the NW

The latter period is pretty indeterminate anomaly wise with the EPS 10-15 not hugely different to NOAA both with a westerly airstream.  Temps around average.

[Frosty.]

6 minutes ago, knocker said:

Not sure I agree with your position of the jet at t240 Frosty old bean it's blowing straight across the Atlantic dipping SE just west of Ireland.

Anyway no sign of any excessive heat or build up of HP on the EPS an NOAA anomalies tonight.

The 6-10 both have slight ridging from the SW and a trough to the NW

The latter period is pretty indeterminate anomaly wise with the EPS 10-15 not hugely different to NOAA both with a westerly airstream.  Temps around average.

Well it's been a long day knocker..my meds have made me tired but it's been fun talking up a possible very warm anticyclonic spell in 10+days...Hope the met office keep seeing something summery in their updates, must be something showing on mogreps and Ec32 otherwise they would be saying there is no signal for any particular weather type in the 16-30 day range. I think we need a good July and there have been signs today that we could get it!

[mb018538]

00z GFS and UKMO show the ridge not quite as strong as on last nights output, so the extended outcome isn't quite as good.....but I guess there will be a lot of swinging between now and then. Last nights output was on the very good side of outcomes.

[knocker]

No surprises with the GFS this morning. The week dominated by slack low pressure over the UK which moves away east to allow  brief ridging by Saturday which soon gives way to systems moving in from the west. No point in looking further ahead as nothing useful will be derived from one run.

[mb018538]

ECM is very different to last nights output too, with low pressure having much more of an influence, and no high building over the UK. It all looks like a small secondary low that wasn't shown to interfere last night has thrown a spanner in the works today...

[mb018538]

I should also point out that there is a marked split on the ensembles as early as day 4/5, which will of course amplify the errors in individual runs further down the line:

 

 

[coldcomfort]

The GFS eye candy (up there with some of the rubbish we see in winter) has most certainly disappeared this morning. Looks like the best we can now expect next week is a north/central-south split, with any dry, warm weather confined to the far SE, but ECM does look to have swung a little too far the other way for now.

[Man With Beard]

3 hours ago, coldcomfort said:

The GFS eye candy (up there with some of the rubbish we see in winter) has most certainly disappeared this morning. Looks like the best we can now expect next week is a north/central-south split, with any dry, warm weather confined to the far SE, but ECM does look to have swung a little too far the other way for now.

This morning's GFS isn't quite up to yesterday's 12Z (which was nearly perfection for summer lovers). But you don't have to go far to find some even better runs - and worse too. This mornings 00Z GEFS for D8-D12 shows a split in the clusters, but I'd say still a favouring warm, predominately dry but perhaps thundery outlook.

By T240, just 6 members could be called changeable or unsettled, like this one:

About 5 members would result in at least a short heatwave. like this one:

  

The remaining 11 members at T240 are also predominately warm or hot and sunny, but they have a minor sinking trough separating two areas of heights. In general, the trough is more a thundery interruption than a breakdown. The trough brings the possibility of a plume ahead of it; here's one of a few examples- doesn't quite make it but close:

  

This latter idea of two areas of heights separated by a minor trough can be seen on the ECM mean for T240, and the ECM op run isn't too far off but with a better developed trough

     

So things beginning to become clearer for the next 10 days - unsettled this week, clearing up at the weekend, at least a short warm/settled spell for most to start the following week (maybe NW areas most at risk of missing out). Then, from mid-week onwards (D9-D12), a few options, but many of them this morning point to something warm and occasionally hot in the SE, possible breakdown but that's by no means the smart option at this moment. Bearing in mind the way June had gone so far, with models progressively holding the Atlantic back as T0 approaches, I remain confident that the final third of June will be very good indeed. In the next few runs, I will be looking out for heights building over the top of a sinking trough over Biscay - that could lock in a heatwave.

 

 

Edited June 13, 2016 by Man With Beard

[knocker]

There is no obvious indication on the ecm anomalies for anything other than unsettled for the next 14 days  The 6-10 has an upper low norther Canada with low pressure extending to a trough NW of the UK. Ergo an upper flow from a westerly quadrant dragging systems in from the west that will probably track north of east thus impacting Scotland the greater. In the 10-15 period a rather more indeterminate westerly flow but essentially we are looking at LP to the NW and HP to the SW so the usual interaction as systems traverse the UK. Nothing damnable but also not that inspiring.

[mb018538]

6z also follows knockers tale above, with more of a standard Westerly flow of sorts. Looks like one of our classic NW/SE splits could develop.

[Polar Maritime]

Certainly a more settled/warmer 6z into the last week of June, As high pressure pushes further North with temps into the mid 20's. 

Edited June 13, 2016 by Polar Maritime

[Man With Beard]

The GEFS 06Z swings more unsettled

A much stronger Atlantic trough on most members. Not many hot runs this time.

[Frosty.]

The Gfs 6z op run turns much warmer and anticyclonic through low res, some cracking charts which follow the peachy gfs / ecm 12z yesterday.

[Fourty Point Three Degrees]

it seems the met office have now ditched the idea of the azores high fully moving northwards in July:

UK Outlook for Tuesday 28 Jun 2016 to Tuesday 12 Jul 2016:

Unsettled weather is most likely across the northern half of the United Kingdom through late June and early July, with showers or longer spells of rain at times, although there should also be some dry and bright spells in between. Southern and in particular southeastern areas are likely to see lengthier spells of drier, warmer and sunnier weather, but still with some occasional rain or showers. The temperature is likely to be generally around normal for the time of year, but perhaps a little above average at times in the south.

 

[Frosty.]

I looked at those gorgeous FI charts on the Gfs 6z earlier but looking at the reliable timeframe its a much different story with a slow moving trough covering the UK and bringing thundery showers mixed with sunny spells but later this week it slowly becomes drier and cooler / fresher from the north as our trough slowly fills in situ and is then shunted away to the east  as the azores ridge builds in across the UK just in time for next weekend bringing a weather window of fine and pleasant conditions but saturday night looks cold by mid / late June standards, even a touch of frost in rural spots, the ridge holds across the south of the UK on sunday and temps rise a little so a nice day further south but turning more unsettled further north. Into next week, low pressure spills in off the north Atlantic with wind and rain followed by sunshine and showers but then towards the end of next week we see a marked pattern change to increasingly warm and settled weather, you know what..I wouldn't mind enduring what the 6z shows in hi res if we get that big change in low res!

[coldcomfort]

59 minutes ago, 40*C said:

it seems the met office have now ditched the idea of the azores high fully moving northwards in July:

UK Outlook for Tuesday 28 Jun 2016 to Tuesday 12 Jul 2016:

Unsettled weather is most likely across the northern half of the United Kingdom through late June and early July, with showers or longer spells of rain at times, although there should also be some dry and bright spells in between. Southern and in particular southeastern areas are likely to see lengthier spells of drier, warmer and sunnier weather, but still with some occasional rain or showers. The temperature is likely to be generally around normal for the time of year, but perhaps a little above average at times in the south.

 

Sadly no real surprise in this change of outlook, with nothing in the 10-14 day 500mb chart being suggestive of the kind of changes needed to promote a lengthy fine, warm spell, despite another one being advertised in FI. Looks to me as if the best we can hope for is a few brief ridges like the one expected this weekend, but overall low pressure looks set to dominate deep into the last week of Jun at least, with the north and west bearing the brunt of the unsettled weather as per in this all too familiar UK summer setup.

Edited June 13, 2016 by coldcomfort

[Frosty.]

49 minutes ago, 40*C said:

it seems the met office have now ditched the idea of the azores high fully moving northwards in July:

 

It doesn't sound that bad, not bad at all for the south actually, it does indicate some Azores high pressure influence across southern uk during july, less so further north but that doesn't mean to say we can't have something like the Gfs 6z is showing in deep FI, even if it's delayed into next month. July is high summer, if we get a poor July after a hohum June, I don't think we can call this a good summer, no matter what happens in August which is often an autumnal month, at least from mid month onwards. I don't think anyone should be getting ready to write this summer off yet but I want to see some heat / Spanish plume activity in July!

[Polar Maritime]

Could we please keep METO extended text forcasts to the relevant threads and discuss only the model outputs in here as it keeps the thread running more smoothly and on topic, Many thanks.

[Man With Beard]

49 minutes ago, coldcomfort said:

Sadly no real surprise in this change of outlook, with nothing in the 10-14 day 500mb chart being suggestive of the kind of changes needed to promote a lengthy fine, warm spell, despite another one being advertised in FI. Looks to me as if the best we can hope for is a few brief ridges like the one expected this weekend, but overall low pressure looks set to dominate deep into the last week of Jun at least, with the north and west bearing the brunt of the unsettled weather as per in this all too familiar UK summer setup.

The last 4 GEFS runs combined suggest not particularly low heights towards the end of June. 850s average close to 9C for London too. That's warm for the end of June.

http://www.meteociel.fr/cartes_obs/gens_display.php?x=306&y=141&run=100&ville=Londres&runpara=0&type=0&ext=1

[Frosty.]

Looking into the GEFS 6z crystal ball shows plenty of high pressure dominated perturbations through late June and the mean indicates Azores ridging across the south of the BI so there are encouraging signs which follow the superb looking 6z op run during low res.. I'm not accepting we definately won't see a nationwide anticyclonic spell by the end of June or early in July!

Edited June 13, 2016 by Frosty.

[phil nw.]

Next week does see a move towards a more normal Summer UK pattern in the ens means ieLow pressure to the north and higher pressure further south.

At least with that setup a better chance of seeing drier and warmer interludes rather than the current picture of a slow moving trough right across the UK.ECM/GFS mean charts/day10

still not settled all the way with the Azores high still rather suppressed and the UK in westerly flow.Temperatures for London slightly better but no heatwave showing.

 

low 20's feeling ok in the warm sunshine i guess so not too bad but as usual it looks better across the south with areas further north cooler and less settled at times.

Yes Frosty as you have just posted later Gef's by day 15 just hinting at the Azores high easing a little further north.

ridging across southern and central parts by then although still that north/south split often seen at this time of year.Let's hope this trend continues as we head towards the last part of June with more widespread fine weather returning. 

 

Edited June 13, 2016 by phil nw.

[Frosty.]

6 minutes ago, phil nw. said:

Next week does see a move towards a more normal Summer UK pattern in the ens means ieLow pressure to the north and higher pressure further south.

At least with that setup a better chance of seeing drier and warmer interludes rather than the current picture of a slow moving trough right across the UK.ECM/GFS mean charts/day10

still not settled all the way with the Azores high still rather suppressed and the UK in westerly flow.Temperatures for London slightly better but no heatwave showing.

 

low 20's feeling ok in the warm sunshine i guess so not too bad but as usual it looks better across the south with areas further north cooler and less settled at times.

Yes Frosty as you have just posted later Gef's by day 15 just hinting at the Azores high easing a little further north.

ridging across southern and central parts by then although still that north/south split often seen at this time of year.Let's hope this trend continues as we head towards the last part of June with more widespread fine weather returning. 

 

Yes Phil good post, fully agree with you.