Model Output Discussions 12z 03/05/2016

[Summer Sun]

Glorious from ECM this morning temperatures would be on the way up without doubt if it came off

[mb018538]

I suspect it's a best-case scenario with the ECM operational output....nearer the time it'll probably end up somewhere between the GFS and ECM.



Nice to see the 15c isotherm (albeit temporarily) over the UK at a reasonable timeframe.

[coldcomfort]

26 minutes ago, mb018538 said:

I suspect it's a best-case scenario with the ECM operational output....nearer the time it'll probably end up somewhere between the GFS and ECM.



Nice to see the 15c isotherm (albeit temporarily) over the UK at a reasonable timeframe.

As is often the case it must be said. I really would caution against anyone taking the overnight ECM as nailed on or even likely for that matter, I noticed John Hammond was at pains to mention the fact there was no sign of any decent settled summer weather on the horizon and GFS looks closer to what we will actually end up with imo, so for those across the N in particular the weekend and early part of next week could actually be pretty dire. As ever more runs needed, but let's just hope ECM is actually onto something for once and this just doesn't turn into another 24-48hr SE centric warm spell.

Edited August 1, 2016 by coldcomfort

[MP-R]

55 minutes ago, coldcomfort said:

As is often the case it must be said. I really would caution against anyone taking the overnight ECM as nailed on or even likely for that matter, I noticed John Hammond was at pains to mention the fact there was no sign of any decent settled summer weather on the horizon and GFS looks closer to what we will actually end up with imo, so for those across the N in particular the weekend and early part of next week could actually be pretty dire. As ever more runs needed, but let's just hope ECM is actually onto something for once and this just doesn't turn into another 24-48hr SE centric warm spell.

Yes, that was a rather daft comment by John Hammond given the number of model runs showing such, quite unlike him. After today and tomorrow, it's not actually looking too bad at all with a high probability of a warm settled weekend. FI starts quite early with regards to the pestering low pressure out in the Atlantic, that influencing where exactly the high pressure goes. All to play for - there's certainly been a strong trend for more sustained settled weather into week 2 of August for a wider swathe of the country for some time now.

[Man With Beard]

23 minutes ago, MP-R said:

Yes, that was a rather daft comment by John Hammond given the number of model runs showing such, quite unlike him. After today and tomorrow, it's not actually looking too bad at all with a high probability of a warm settled weekend. FI starts quite early with regards to the pestering low pressure out in the Atlantic, that influencing where exactly the high pressure goes. All to play for - there's certainly been a strong trend for more sustained settled weather into week 2 of August for a wider swathe of the country for some time now.

I must agree. No certainty for sure, but no sign?? He obviously doesn't spend as long as we do on the models ...

Still a bit of daylight between the ensemble means this morning but wouldn't expect anything desperately unsettled from these, and quite possibly high pressure dominated with a W or NW flow

The GEM looks a good fit in all honesty - which would be: hot for most at the weekend, slow breakdown from the north next Monday/Tuesday (still hot in the south), a weak breakdown further south for mid-week (possibly rainless), and a cooler high pressure builds back in behind for all by the end of next week. Sounds pretty reasonable to me - but beyond a hot weekend, still a few options on the table for next week pretty much as I supposed in my post yesterday evening.

Edited August 1, 2016 by Man With Beard

[coldcomfort]

27 minutes ago, MP-R said:

Yes, that was a rather daft comment by John Hammond given the number of model runs showing such, quite unlike him. After today and tomorrow, it's not actually looking too bad at all with a high probability of a warm settled weekend. FI starts quite early with regards to the pestering low pressure out in the Atlantic, that influencing where exactly the high pressure goes. All to play for - there's certainly been a strong trend for more sustained settled weather into week 2 of August for a wider swathe of the country for some time now.

Yes, the track of the weekend low is all important, but if we can keep it far enough NW then summer could make a very quick reappearance...however the potential is there for a real taste of Autumn if things go the other way. As you say all to play for, which must count for something I guess!

[coldcomfort]

06 GFS sticking resolutely to it's guns and not buying the ECM version at all out to T+168hrs.

[mountain shadow]

1 hour ago, coldcomfort said:

06 GFS sticking resolutely to it's guns and not buying the ECM version at all out to T+168hrs.

Right through to the end of the run actually. The 6z has rainfall somewhere across the UK on every frame of the run, particularly in the North West but not exclusively. I see no sign of any spell of drier weather in the next three weeks although granted the further South and East you are the better.

[Man With Beard]

It's a topsy-turvy day on the models so far. Some heat for the weekend still well on the cards - 27/28C looking highly likely in Eastern England over two or three days. 

But on the GEFS 06Z, by Tuesday next week the secondary depression totally scuppers the potential for a UK high, and leaves us in NWlys - the High stays painfully close in the Atlantic but not fun for Northern and Eastern areas in particular. What the mean doesn't show is that most runs have some sort of low pressure or trough in the North Sea:

Most runs do eventually topple the Azores High into the UK but because its northwards progress was interrupted by the secondary low, it topples over the south rather than the north - much more vulnerable for flattening by the Atlantic jet.

Mind you, with all the different modelling around this morning, that seems a lifetime away at the moment. I'm not discounting all of the runs with a settled outcome from yesterday or this morning yet at all. After all, just a couple of nights ago, the models didn't even have this mini-heatwave for Friday-Monday showing. 

 

 

Edited August 1, 2016 by Man With Beard

[SMU]

If we look at the current runs they are very similar to the hot spell the other week with a surge NE of the azores High -

up until around 120-132 the models wanted to flatten the pattern quickly & carve the trough out to the North -

Thats whats being modelled again - however the ECM is prolonging the heat - if last time is anything to go by ECM could be closer to the mark... - lets hope so!

s

[Summer Sun]

High-pressure returns at the weekend if UKMO is right

Edited August 1, 2016 by Summer Sun

[Captain Shortwave]

I suppose it is good new that the UKMO has delivered a similar result to the ECM for next weekend.

   

High pressure building through most of Europe including the UK,

The GFS is a lot flatter though

   

Still fine in the south but wetter and windier across Scotland/ Northern Ireland and possibly northern England. 

Given the complexities that tropical systems can cause on the model output, we can certainly expect changes in the coming days, but a solution like the ECM or UKMO would be very good for most of the UK.

[Man With Beard]

Take a quick look at the GEM before you have your dinner. 18C uppers over the UK for 48 hours Sunday/Monday. Overdone? Maybe. But BBQ weather all the same! 

[Summer Sun]

GEM gives us 3 hot days before some fresher air moves in

[northwestsnow]

Beautiful UKMO this evening

http://old.wetterzentrale.de/pics/Rukm1201.html

 

http://old.wetterzentrale.de/pics/Rukm1441.html

GFS not so clever, we await ecm for the casting vote

[northwestsnow]

ECM not as good as UKMO but better than GFS so maybe a halfway house, still looks warm and settled for the majority as we move towards the weekend..

[northwestsnow]

Well ECM is actually OK, any warmth over the weekend is pretty restricted to sat/sun but at 168 we get another shot from the azores high meaning it will dry for the vast majority.

Rest of the run should be fine but with differences at 120 to 144 i will reserve judgement on the outcome..:)

EDIT Al though John Hammond has apparently suggested no sign of anything settled on the horizon, maybe i read it wrong as i was on my work lunch.

I know we have been led up the garden path by the NWP in the past but surely JH was misquoted? With the ukmo/ecm both suggesting a warm fine weekend away from the NW i dont understand his comments.

Edited August 1, 2016 by northwestsnow

[Gordon Webb]

1 hour ago, Man With Beard said:

Take a quick look at the GEM before you have your dinner. 18C uppers over the UK for 48 hours Sunday/Monday. Overdone? Maybe. But BBQ weather all the same! 

not if you like cold BBQ I would imagine

[sparky1972]

please please please can the people with more experience than me, so thats everyone, haha, give me the hope of some warm settled weather from Aug 12 till 19th, off to north yorks for a week with the family, i really love reading the posts here, keep up the good work all

[mb018538]

Hi sparky, unfortunately that's just too far away at the moment....the models can't even agree on the weather 5-7 days ahead, let alone 11+ I'd say check back in 5-6 days time for a much better idea 

[mountain shadow]

20 minutes ago, sparky1972 said:

please please please can the people with more experience than me, so thats everyone, haha, give me the hope of some warm settled weather from Aug 12 till 19th, off to north yorks for a week with the family, i really love reading the posts here, keep up the good work all

Based on current model output and factoring the Met Office longer range forecast it is more probable that you will have a more unsettled period of weather than settled. That is not to say that your week will be a washout, but you will need to prepare for some inclement weather too.

[Man With Beard]

On 26/07/2016 at 19:52, Man With Beard said:

Back after a few days away - what message does the GEFS bring tonight? Well, the upcoming ridge from the Azores looks flattened out a little, so perhaps only some summer joy for southern parts at the start of next week. Then by D10, almost all ensembles are flat with the worse the weather the further north you go. 

But by D12, a bit of a change appearing, as the whole pattern is moved north a tad, as shown by the mean:

and this reflects a number of dramatically improved ensembles - 17 out of 21 ensemble members shown considerable progress north of the upper high in some proximity to the UK - many just west of the UK, a few to the east and a few directly over us. I felt that this ensemble was perhaps the one most in the middle:

now being D12, this is just a "trend watch" at the moment and not to be taken too seriously, but if the pattern starts to move towards T200, it will need careful watching. 

I'm also struck by the amalgamation of the past 4 GEFS ensembles that Meteociel provides - I picked Manchester for this:

aside the short burst around D7/D8, the number of runs getting into the 10C-15C at 850hpa keeps increasing as the run goes on - looking at the London chart, quite a few get close to 20C (6 getting between 15C and 20C in the last ensemble run alone).

Unusual for the ensembles to pick out so many hot runs at long distance.

So plenty of hope there for summer seekers.

 

This is what I posted last Tuesday, with the charts forecasting for the next Monday. At that stage, T288 - now T156

The reason I'm posting this again is just to show - the ensembles CAN be useful guide even way out into the distance - IF (and this is a big "if") - there is strong clustering around a certain pattern. It's not the mean that helps, it's the existence of a large cluster (say 70% of the runs or more). Also, the presence of very warm ensembles is significant, as you rarely get more than a couple at a time out to T300.

Perbutation 1 (the second post in the chart above) seemed fairly representative at the time. Aside the trough to the north - it was very, very close to what we're now forecast to get in the more reliable range:

    

p.s. Sparky - ensembles for Aug 12-19 currently all over the place so very low confidence on what might happen that week just yet, IMO!!

Edited August 1, 2016 by Man With Beard

[MP-R]

1 hour ago, sparky1972 said:

please please please can the people with more experience than me, so thats everyone, haha, give me the hope of some warm settled weather from Aug 12 till 19th, off to north yorks for a week with the family, i really love reading the posts here, keep up the good work all

Very much depends what happens with the low pressure area to the north of the UK Sunday into Monday. The last week has shown how it sucks up high pressure underneath which effectively forms a block resulting in a long-lasting settled spell. However, a change in direction can scupper all chances and usher in a shower northwesterly where the best weather would be further south and west. In the event that everything flattens out and we return to a westerly, the further south you can be the better. I've also got my eyes on some of those dates for the Bristol Balloon Fiesta, and the visit of a Spanish friend who had visited me in March but was rewarded with wind, rain and thunderstorms so I said come back in the summer (August is after all a summer month every else in Europe lol).

Fortunately there haven't been too many model runs showing predominantly unsettled weather and the reliable timeframe is very much the end of this weekend, before which we should have fine and warm weather quite widespread on Saturday, more reserved for the south and east on Sunday. After that is anyone's guess at the moment. 

Hope that makes sense. It's a lot to get one's head around when new to the models.

[Frosty.]

How do I summarise tonight's Ecm 12z ens mean..well here goes..

This shows a decent spell of warm settled weather, especially for the south of the uk later this week including the weekend and early next week, the high eventually pulls west into the atlantic but leaves a ridge close by to the southwest and I would imagine beyond T+240 the high would build in again. 

[Man With Beard]

GFS continues to be hot for the weekend and Monday over most of England, could 30C be reached again?

everyone much cooler by midweek as a slow clearing low drags a NWly in its wake

Sadly the second low moving in on Tuesday has put paid to height rises taking over in northern areas - for this run at least. Probably best chance for good weather up north in next seven days is that storm tracking further towards Iceland. ECM was a bit better for this yesterday, hopefully it will repeat this morning.