model discussion Model output discussion 11th July onwards

[Methuselah]

Here the GEFS 06Z temperature ensembles for Bedfordshire and Aberdeenshire -- it might get a tad taters up there!? 

        

[Frosty.]

The GEFS 6z mean looks pretty stable during the early days of September with predominantly settled conditions but I must admit the ensembles become rather frisky later with everything including the kitchen sink thrown in!…however, that aside, the mean looks more settled than unsettled across southern u k even by the end, probably changeable would be the best way of describing it longer term with the most unsettled being further n / nw.

 

[MATTWOLVES 3]

1st out of the blocks is the ICON.. and trust me it delivers! If anything the High is sinking more SE later in the run..a bit like UKMO earlier. Perhaps better sunshine amounts for places that are missing out currently moving forward.

Whatever your poison...have a super Bank Holiday folks.

[Frosty.]

I cannae be bothered waiting for meteociel to load T+120 hours Ukmo 12h!!!…T+144 is nae bad! 

Edited August 27, 2021 by jon snow

[Methuselah]

Nae doot aboot it; the GFS 12Z has a certain 'nae badness' look to it, at Day 10:

     

[Frosty.]

The Gem 12z goes from nae bad to nae good by the end!

[Mike Poole]

1 hour ago, jon snow said:

The Gem 12z goes from nae bad to nae good by the end!

Yes, GFS 12z is a good run with long lived settled conditions, but GEM and ECM are not and have it all caving in about a week from now…one to watch.

[damianslaw]

3 minutes ago, Mike Poole said:

Yes, GFS 12z is a good run with long lived settled conditions, but GEM and ECM are not and have it all caving in about a week from now…one to watch.

Odds are probably stacked against the blocked scenario holding for more than 2 weeks, not implausible, just saying probability favours a collapse at some stage.. we shall see, 14 days would be very good going.

[Frosty.]

The ECM 12z operational looks pretty settled / anticyclonic up to and including day 6 (T+144 hours) but then trends more unsettled with probably heavy and thundery showers? ⛈  …there’s a carrot dangled at day 10 for much warmer air to flood across the u k subsequently but having said that, the uppers (850’s) for most of the run look decent when you consider we are almost on the cusp of the meteorological autumn!  

[Guest]

2 minutes ago, damianslaw said:

Odds are probably stacked against the blocked scenario holding for more than 2 weeks, not implausible, just saying probability favours a collapse at some stage.. we shall see, 14 days would be very good going.

Ironically a breakdown of the blocking will probably deliver better conditions than many are being subjected to, unless that is it’s full steam ahead from the Atlantic.

[Methuselah]

GEFS 12Z ensembles are, err... Pretty good:   

[Mike Poole]

17 minutes ago, Ed Stone said:

GEFS 12Z ensembles are, err... Pretty good:   

Is that better than nae bad, Pete?  JMA was a good run this evening, T132, T264:

Power to add into September there, I would think.  

Edited August 27, 2021 by Mike Poole

[Frosty.]

I’m wheeling out the NAVGEM 12z…cos..guess what?…it’s nae bad!  

[Mike Poole]

ECM ensembles, I’ll post the uninteresting chart first T240:

Kind of saying ‘dunno’! 

T144, and one thing of note throughout the latter half of winter, spring and summer, is the tendency for heights over Greenland:

Be kind of interesting if that was still there for the first half of next winter…

 

[Mike Poole]

Looks too much uncertainty to post the ECM clusters up to T240, but just to note the extended ones:

2 out of 3 bring back either a strong high, or a plume.  Maybe heading to standard mid September warm weather.  Happens many years when the schools go back…

[stodge]

Evening all

I'm struggling to see much clarity as we move into September.

ECM and GEM keep northern blocking which allows Atlantic LP to roll in to the British Isles on a southerly jet.

GFS and JMA are much better keeping HP close to or over the British Isles - I'm interested to see GFS introducing ex-hurricanes though as always with these modelling their exact trajectories seems an inexact science at best. One seems to move NE, NW and then NE round the Azores HP - GFS Control has an ex-tropical feature moving in towards NW Europe.

[Frosty.]

The Gfs 0z operational is an anticyclonic run, pretty much dry throughout for the majority of the u k and generally warm too, even very warm at times further south for the time of year considering most of the run is very early autumn and not summer!!!!!  

[Frosty.]

The Ukmo 0h turned out nae bad / pretty good didn’t it?  

 

Edited August 28, 2021 by jon snow

[Frosty.]

Most of the ECM 0z operational is anticyclonic  (the next week or so) but then it probably turns more showery?, perhaps with thunder ? ?..and the run ends on a more autumnal note , temperature wise, generally speaking it looks warm, perhaps becoming very warm for a time?…the uppers (850’s) certainly support that idea anyway before it goes Pete tong at the end! 

Edited August 28, 2021 by jon snow

[Frosty.]

Check out the JMA 0h! …nice run and a very happy ending!   …autumn?…pffft, more like high summer!  

Edited August 28, 2021 by jon snow

[sheikhy]

Finally ecm backs down and moves TOWARDS ukmo and gfs and prolongs the high even more!!dunno whats been happening with the ecm in the last couple of days!!considering its a major model its performance in the atlantic has been pretty shocking!!you can see the changes as early as 120 hours!!ukmo has been the most stable for the last week!!

[mb018538]

We’re probably dry until next weekend at least - after then we have a bit of a split with the gfs and gem much more settled than the ecm.

Hurricanes starting to show their hand too!

[johnholmes]

Based on the 500 mb anomaly charts bit EC and especially Noaa, I would be very wary of expecting a continuation of settled weather under the influence of high pressure much beyond somewhere between day 7/8 to day 10/12 from today. No sign of a really active Atlantic with this change, yet. But at this time of year the main hurricane season is in full swing and it needs just one to get into the North Atlantic and predicting beyond 2-3 days becomes fraught with uncertainty, whatever model anyone uses.

[Methuselah]

GEFS 00Z temperature ensembles are nae bad:  

[Frosty.]

Overall I would say the GEFS 0z mean indicates a predominantly settled outlook lasting well into early September, lasting longest further south and for the most part, decent temperatures too..of course the mean is broad brush but on the face of it, extends summer into autumn..  !