Model Output Discussion - Into Summer 2020.

[Mike Poole]

14 minutes ago, damianslaw said:

Too much scatter beyond the 144hr timeframe at present, expect swings and roundabouts from models run to run. In the short term - heights building through the UK - a surge of very warm uppers on a continental flow, then a case of seeing how the ridge is broken down by the atlantic trough to the west.

Heights building over the Pole not a great sign longer term - atlantic trough destined for the UK will be a major threat.

I think you are trying to have your unsettled cake and eat it in that post!

[Djdazzle]

5 minutes ago, Mike Poole said:

I think you are trying to have your unsettled cake and eat it in that post!

A trough over the U.K. is always a threat, even in settled summers! But I get what he is saying.

[MATTWOLVES 3]

The mean, apart from it being a bit more unsettled this Weekend is pretty good for the bulk of the next 10 day's.. Decent warm conditions to the South, but nothing to write home about in the far North... Typical Summertime set up in all honesty.

With reference to Damianslaw post above, I see nothing for Southerners to get to downhearted about.. If your much further North like his location and further North, its just average.

Hopefully I will bring you an EC46 update later..

Edited June 22, 2020 by MATT☀️

[Mark wheeler]

1 hour ago, Zak M said:

216

Definitely some warmth building there, GFS picked up on it too...

   

Also Gem this morning as I posted  but to a lesser degree . 

[mb018538]

I like that the D10 mean has that trough deepening off Newfoundland. Mean doesn’t really have a Greenland high at that range either, so let’s hope it’s sniffing something out.

[Mike Poole]

Who is winning in the battle of the means, ECM and parallel T168:

No score draw there, T240:

Parallel just edging it there, more positively tilted jet on the mean?

[Zak M]

There's clearly signs of possibly more settled weather developing as seen on the 8-10 day 500mb mean chart. Mainly more settled and warmer for the south though.

[johnholmes]

In reply to Zak above. I do not see things quite like you I'm afraid. Yes the two charts are not that different. Both show an Atlantic influence with only small +ve height rise indicators south of this. The GFS has the upper air flow from north of west with EC a more westerly.

My take would be there is not much signal, from those two charts, for any build of ridges in the upper air or at the surface. Rather unsettled with perhaps a NW-SE split.

This supported again this evening by the NOAA 6-10 and its 8-14, see below

Climate Prediction Center - 8-14 Day 500mb Outlook

WWW.CPC.NCEP.NOAA.GOV

 

[Daniel*]

17 minutes ago, Zak M said:

There's clearly signs of possibly more settled weather developing as seen on the 8-10 day 500mb mean chart. Mainly more settled and warmer for the south though.

Definitely doesn’t look nationwide away from far south or much impetus to really build in, quite poor and cool as a matter of fact for N UK. Similar to ECM 12z the trough on a NW>SE axis which ain’t good for us in NW Europe, the AO is going negative while this doesn’t mean we are destined to see bad weather, it makes life harder. I don’t think July will start badly for most of us, but the chance of heat seems very slim to me. 

[Djdazzle]

13 minutes ago, Daniel* said:

Definitely doesn’t look nationwide away from far south or much impetus to really build in, quite poor and cool as a matter of fact for N UK. Similar to ECM 12z the trough on a NW>SE axis which ain’t good for us in NW Europe, the AO is going negative while this doesn’t mean we are destined to see bad weather, it makes life harder. I don’t think July will start badly for most of us, but the chance of heat seems very slim to me. 

Maybe. But things seem to be changing so quickly at the moment, and there doesn’t seem to be any really strong signals. I think there is as good a chance of hot weather as not.

Even last week, there was a thread on here saying 30C was very unlikely this June, and it was broadly supported by modelling. I get the feeling that this summer will be very hard to pin down. Don’t think it will be a washout though.

Edited June 22, 2020 by Djdazzle

[MATTWOLVES 3]

Out to week 3 with EC46 and there remains a fair bit of fine weather with ridges building in from the SW at times.. We tend to have lower heights around Iceland and pressure over Greenland tends to be steady, not really high or really low... 1010mb or so. Certainly at this stage am I not seeing a Zonal rut. So it perhaps seems to be carrying on where we left off... Some warm settled spells followed by rinse and repeat but nothing to suggest anything that would be really unsettled and long lasting.

[Mark wheeler]

Well , The Navgem tonight wasn’t that great tonight to be honest but keeping up with recent tradition I’ll give This lovely chart. 

[Man With Beard]

Any signs for the start of July? Need to wait a bit longer. ECM has two clusters tonight - Either hideous or heatwave! 

 

[Fourty Point Three Degrees]

25 minutes ago, Man With Beard said:

Any signs for the start of July? Need to wait a bit longer. ECM has two clusters tonight - Either hideous or heatwave! 

 

I think we all know which one will one is most likely

[Methuselah]

Friday's still looking good, for some thunderstorms, according to the GFS 00Z op. Though, rather worryingly IMO, there's nothing showing on either the NW or the BBC 14-day forecasts -- cooler everywhere, come Sunday:

    

    

     

  

    

So, plenty of potential interest if, like yours truly, warm and changeable weather is your thing!

The GEFS ens look, to me, as if the suggest an alternating pattern (warm to dry to warm again...?) developing, but it's difficult to disentangle as the time-scales vary from ens run to ens run; the SLP ensemble shows this better:

    

    

Not much rain in there, though, it has to be said!

NH profiles -- which, thankfully, show no indication of any northern blocking:

    

    

And now, it's off to do some Power Weeding; one step up from Extreme Stamp Collecting!

Edited June 23, 2020 by General Cluster

[Guest]

Hmmm ECM & GFS show a few showers and possibly TS, early Friday morning, Arpege not interested at all in any thundery  breakdown. Usually by now the models would be suggesting on some sort of convective out break through France, I’m not seeing anything like that unfortunately. Feels like the heat will go out with a whimper opposed to a bang....

[mb018538]

Much less promising output this morning, but to be expected. If we look at last nights 12z ecm day 10:

Versus this morning:

 

The key trough alignment out in the Atlantic has changed and is much closer to the UK, with less amplification. Wouldn’t be seeing any high pressure building off today’s chart put it that way.
As @Man With Beard posted last night, the ensembles were split nearly 50/50 on these two outcomes occurring. Last night we got the good one, this morning the rubbish one.

[Gordon Webb]

it's amazing what unwelcome outcomes both convective and otherwise do to forum attendance

[Djdazzle]

Let's see if the 12z runs go back to a more favourable outcome. I bet they do (with no scientific basis behind this theory!)

[mountain shadow]

Looks like the rest of GB to join the North West in the horrendous Summer weather.

The CFS had been predicting a decent rise in AAM for sometime but continually backed off and now shows only a moderate rise to around neutral. Not sure why money is spent on this area when it's clearly rubbish at prediction.

 

[Djdazzle]

I never understand why people jump on one set of runs, and assume it's a done deal!

Agree about the CFS though - it is pretty naff!

[mb018538]

9 minutes ago, mountain shadow said:

Looks like the rest of GB to join the North West in the horrendous Summer weather.

The CFS had been predicting a decent rise in AAM for sometime but continually backed off and now shows only a moderate rise to around neutral. Not sure why money is spent on this area when it's clearly rubbish at prediction.

 

CFS has a positive AAM bias. ECM ensembles weren’t ever showing such a rise, and look like being right again.

[Guest]

Payback model output in full flow this morning, not only does it increasingly look likely we are going to be robbed of a decent thundery breakdown, GFS & GEM ensembles keep a big scatter once we head into July. ECM just stalls the upper trough over UK leaving the low nowhere to go so it just hangs around for days on end, probably not too bad in the inland parts of the south east however pretty naff further north and west you go!

[Tim Bland]

1 hour ago, Alderc said:

Payback model output in full flow this morning, not only does it increasingly look likely we are going to be robbed of a decent thundery breakdown,

Thundery breakdown still there on ECM and GFS this morning for Friday? 

[Djdazzle]

1 hour ago, Alderc said:

Payback model output in full flow this morning, not only does it increasingly look likely we are going to be robbed of a decent thundery breakdown, GFS & GEM ensembles keep a big scatter once we head into July. ECM just stalls the upper trough over UK leaving the low nowhere to go so it just hangs around for days on end, probably not too bad in the inland parts of the south east however pretty naff further north and west you go!

I wouldn't say robbed, because we all know that thundery breakdowns are very rare. I never expect them, no matter what the models are showing.

The big scatter only highlights the uncertainty, so I still think all options are on the table. I certainly wouldn't bank on the 00z runs being correct.