Model Output Discussions 12z 01/06/2017

[Frosty.]

There are some quite autumnal looking charts on the Gfs 6z through low res which would be appropriate since the meteorological autumn is less than 2 weeks away now.

Edited August 20, 2017 by phil nw.
Removed the off topic comments

[mb018538]

7 hours ago, Frosty. said:

There are some quite autumnal looking charts on the Gfs 6z through low res which would be appropriate since the meteorological autumn is less than 2 weeks away now.

Bar a couple of warmish humid days Tuesday and Wednesday, that could be it for meteorological summer. Plenty of ensemble spread as you'd expect with things as they are.

We might get the odd September treat, but come mid month I'll be looking for some crisp mornings and pleasant afternoons 

Edited August 20, 2017 by phil nw.
Removed the off topic comments

[Frosty.]

7 hours ago, mb018538 said:

Bar a couple of warmish humid days Tuesday and Wednesday, that could be it for meteorological summer. Plenty of ensemble spread as you'd expect with things as they are.

We might get the odd September treat, but come mid month I'll be looking for some crisp mornings and pleasant afternoons 

Agreed, summers over bar the whimpering (never even started in scotland!) quite a changeable outlook with no sign of any sustained settled weather on the horizon..looking forward to those crisp morning's too.

Edited August 20, 2017 by phil nw.

[Frosty.]

In a nutshell, there is no sign of a pattern change, we are looking at more of the same as we have seen in recent weeks with generally changeable / unsettled atlantic conditions, especially further north by north-west with occasional ridging, mostly for the south where longer drier, brighter and warmer intervals occur..so, summer 2017 looks like continuing to fizzle out during the rest of august.

Edited August 20, 2017 by Frosty.

[Polar Maritime]

Back to discussing what the models are showing please. This is not the Murr thread.. And it's not even Autumn yet!

[Summer Sun]

UKMO going for a settled start to the BH weekend as per the 00z

[knocker]

Pretty good example of a ridge central Canada and low pressure over the Arctic and trough Greenland /UK with a neat conduit around the HP for systems to impact the latter

[Frosty.]

The Gfs 12z is a generally changeable run with some unsettled and cool spells, especially further n / nw but also some pleasantly warm and settled periods with high pressure / ridging, mainly across southern uk.

[Frosty.]

The Gem 12z, as yesterday's is going for high pressure next weekend and then as the high drifts to the east a very warm / humid continental southerly flow early week 2 with a chance of thunderstorms following the spell of settled warm weather across most / all of the uk.

Edited August 20, 2017 by Frosty.

[phil nw.]

A couple of off topic posts have been hidden.Please use other threads for discussing Autumn/Winter possibilities.

As PM Has already stressed above please stick to current model outputs in here please.

Cheers all. 

Edited August 20, 2017 by phil nw.

[Captain Shortwave]

Three models decide to drop an area of low pressure towards Iberia at day 5

      

This allows the heat to our east to build northwards again as the Azores ridge builds towards the UK over the top of the low near Iberia. The result is a settled spell with temperatures on the rise. The ECM and GEM deliver something pretty decent, both going very warm.

GFS

Competely different to the others but looks similar to the consensus up to today. So perhaps the others have latched onto a different path in terms of the mid-range. But this new solution does offer better conditions for the UK than the GFS operational at least.

Edited August 20, 2017 by Captain Shortwave

[mb018538]

Everything is going To depend on if that low drops into Iberia....if it does as per UKMO and ecm we may salvage something respectable. If it goes as the GFS paints things, it's rapidly downhill!

[knocker]

1 hour ago, Captain Shortwave said:

Three models decide to drop an area of low pressure towards Iberia at day 5

      

This allows the heat to our east to build northwards again as the Azores ridge builds towards the UK over the top of the low near Iberia. The result is a settled spell with temperatures on the rise. The ECM and GEM deliver something pretty decent, both going very warm.

GFS

Competely different to the others but looks similar to the consensus up to today. So perhaps the others have latched onto a different path in terms of the mid-range. But this new solution does offer better conditions for the UK than the GFS operational at least.

Yes as you point out the cut off upper dropping into Iberia and simultaneously promoting the ridge to the east would be a good solution for at least the southern half of the UK with a slack gradient and temps rising above average and at the same time holding the mayor trough to north west for a while. Of course we need to see what the EPS comes up as the GEFS isn't buying it

 

 

Edited August 20, 2017 by knocker

[Summer Sun]

ECM looks better from t144 onwards pressure is much higher than of late and we have some welcome warmth/heat making a return

[BlueHedgehog074]

This is the 12Z NAVGEM's idea for day 5 - probably closest to the UKMO's solution that the Captain posted above with the circular shallow cut-off upper Low to the South-West of the UK (yellow colour) with the Azores High Pressure system ridging over the top

And looking further ahead, the Azores squeezes it's ridging through the UK and to the East

Summer could be restored for a while towards end of this week - maybe even for Northern UK, although if this does happen, it could be quite transient with a possibility of Lows in the Atlantic trying to break through from the West

Hopefully the GFS 18Z (Edit: and the GEFS that knocker spoke about) will be a good boy and walk along the footprints of the UKMO/ECMWF/NAVGEM and GEM.

Edited August 20, 2017 by DiagonalRedLine

[Singularity]

      

Depending on cloud amounts, I daresay the SE corner could chase down the hottest final weeks of August on record from this ECM 12z run.

While it's true that both UKMO and GEM offer good support for the weekend ridge that kicks things off, GEM is keen to remind us how easily they can displace away from us again should the Atlantic jet not take on such a simplistic SW-NE orientation through/near to Iceland as the ECM 12z shows.

Got to give ECM a round of applause for effort though .

[Frosty.]

Terrific Ecm 12z later in the run, especially for southern uk...this could raise hopes of a summery late August! Lovely stuff

Edited August 20, 2017 by Frosty.

[damianslaw]

Lots of room for change in the longer range model output - its quite a volatile unpredictable set up at the moment, largely due to the strong influence of ex-hurricane activity, which means the reliable timeframe is about 4 day tops at the moment. Bank Holiday is a world away in this respect. However, reading between the lines and looking at the overall background base state, I suspect any ridge development will be very weak, and the dominant force will below pressure becoming slow moving and quite erratic with the atlantic trough eager to settle up shop over the UK - sorry but I can't see any sustained settled conditions on the cards this side of the end of August.

[Frosty.]

8 hours ago, Frosty. said:

Agreed, summers over bar the whimpering (never even started in scotland!) quite a changeable outlook with no sign of any sustained settled weather on the horizon..looking forward to those crisp morning's too.

It just goes to show how things can change, I was negative earlier but the 12z Ecm / Gem, especially the Ecm shows we are not out of the game in terms of a summery end to Summer

Edited August 20, 2017 by Frosty.

[knocker]

Last evening's ten day anomalies, although on the same page, have enough differences in areas that give some leeway for interpretation of the detail of the evolution from the det runs to make things interesting.

The key, as it appears to me, seems to be the precise orientation of the trough in the Greenland/Iceland area in conjunction with the Azores pushing north to the south west and the trough to the SSW of the UK, if indeed one gets established in that area as seems very likely.

This will determine whether the trough to the NW becomes more influential with systems tracking around the Azores or whether low pressure to the south can initiate some WAA or indeed a combination of the two resulting in a N/S divide once again. Quite a fine balancing act maybe

In the later time frame all seem to indicate a more zonal westerly with the trough to the north west being the main player and thus a more general unsettled regime.

For the next couple of days we are still under the influence of the death throes of Gert with the warm front edging north and the cold east so some cloudy drizzle type weather clearing from the south before more rain pushes in from the west whilst at the same time dragging some quite warm air up from the south.

So quite showery on Wednesday as the front meanders across the country and the shallow low to our west is not yet done as it also meanders east to be over Scotland by 12z on Friday bringing a more organized band of showers or persistent rain whilst at the same time a trough has slipped around the HP to the south west.

Which neatly brings us to the weekend and the start of the dodgy area, The low gradually at last loses it's identity on saturday and and gives way to some very transient ridging which is quickly squashed by the next trough winging in from the north west which impacts N.I and Scotland by Sunday with the southern half of the UK staying under the influence of the ridge. Although a cut off upper low has formed over Iberia from the previously mentioned trough, at this stage it becomes isolated with the large trough area the NW/N being the main player Thus the beginning of next week becoming quite breezy with frequent showers and longer periods of rain but once again the north bearing the brunt. Just to reiterate next weekend and after is a long way from being nailed down.

 

 

 

Edited August 21, 2017 by knocker

[Summer Sun]

UKMO maintains the high for the BH weekend

[knocker]

Not a complete surprise that the ecm varies in detail from starting next weekend By Saturday the low has lost it's identity and a very diffuse ridge covers the UK with a trough that has tracked down from the NW adjacent to Iberia, This trough has activated some thundery activity over Spain/France which tracks north east to impact the south of England Sunday morning whilst simultaneously the next trough is making inroads from the north west making Sunday in general and interesting day.

Early next week a deep depression arrives and is SE of Iceland by Tuesday 00z thus the UK in strong, showery, westerly flow with the weather with gales once more over Scotland.

[mb018538]

Meto run is a blinder! Much variation though, so more runs needed to clear this up. Could that little cut off low save the day???

[Frosty.]

30 minutes ago, Summer Sun said:

UKMO maintains the high for the BH weekend

Fingers crossed Gavin, looks very nice

[Summer Sun]

1 hour ago, Summer Sun said:

UKMO maintains the high for the BH weekend

UKMO extended keeps it going into Monday maybe some rain for NW Scotland but dry and most