Model output discussion 14/04/18

[Man With Beard]

ECM clusters for the 00Z had just one cluster from start to finish. I suspect this reflects the lack of certainty in where things are going after mid-next week. 

However, the mean charts for 500mb heights and 850hpa temperatures confirm that the ECM ensembles are trending back towards something a little more settled and possibly hot still between the 14th and 19th of July. 

500mb charts:

  

The first chart (D10) confirms the Iberian low is expected to track towards the UK, a bit like it is doing at the moment. What the chart cannot tell us is how developed this low will be, and its exact position. Highly developed/over the UK = very thundery, possibly cooler for a while. Little development/not directly over the UK = little influence, some showers at very best (worst?!?), little change in terms of heat. Of course a low to the SW at this time of year can engage a hot plume ahead of it, and so the ensembles are taking this possibility seriously.

The second chart (D15) shows a flatter pattern but still with a fairly elevated jet, and above average heights for all. At worst changeable with good warm spells and short frontal interruptions, but possibly remaining fairly settled in the south. 

850 temps, D12 & D15:

  

A good 2-3C warmer than yesterday morning's on both. The 10C line never leaves England, and the 8C never gets south of the Highlands. These are still well above average figures, and suggest the heat from the current pattern is more likely to remain than to be brushed aside.

So two ensemble runs in a row giving signs that the heatwave could possibly continue into a fourth week (14th-21st July). But it's still tentative, and it's not in a position yet where interruptions couldn't materialise, especially bearing in mind where the ensembles were 36/48 hours ago.

Just as an extra comment - the latest GFS 06Z from T192-T300 is pretty much bang on with the ECM 00Z ensembles mean, if anyone wants a "meteociel" representation of what the current situation looks like

 

Edited July 4, 2018 by Man With Beard

[mb018538]

The 6z op actually fits the average quite nicely until the very end - and also mirrors the ECM - so could be an indicator as to the direction of travel. No Atlantic onslaught for the time being perhaps?

Edited July 4, 2018 by mb018538

[Guest]

28 minutes ago, mb018538 said:

The 6z op actually fits the average quite nicely until the very end - and also mirrors the ECM - so could be an indicator as to the direction of travel. No Atlantic onslaught for the time being perhaps?

Seems like the plume option and over-deepening of the upper trough may have been over egged again leading to a continuation of high pressure, temps generally 25-31C depending on location and associated shelter from onshore breezes. I know some don't like the warm weather however it would be nice if the sun could stay until at least the World Cup Final........

[Singularity]

Totally up in the air regarding that low across Europe next week; how deep it is, how far west, how much northward progress it makes... none of these things are clear.

Longer-term, on the other hand, is finally starting to display a trend toward the more Nino-like setup with troughs digging down in the N. Atlantic and ridges tending to locate in the UK-Central Europe-Scandinavia region. The late stages of the GFS 06z make for a fairly good example of this .

[shaky]

First signs on the 12 gfs that the biscay low is further south and high pressure ridging back in!!its unreal!!hot temps continuing well into fi!!!madness!!

[Captain Shortwave]

      

      

Onwards we go, no real change in conditions with high pressure in charge bringing lots of sunshine and only isolated afternoon showers, again the south could come under threat from a thundery low into week 2 but a lot could change there.

Temperatures continue in the same frame really, it looks very warm to potentially hot but nothing overly excessive in terms of heat or indeed the feel with humidity never being too high under that high. Just remember the sunscreen.

Obviously the dryness is probably the bigger concern now in my opinion as frankly rainfall look minimal to non existent.

It looks like 30C will be possible from tomorrow onwards for potentially a period of time that could exceed that of last week. Arpege showing a 30C across western parts of East Anglia tomorrow and the temperatures rising by a degree each day with the warmth spreading. This is possibly overdone???

      

 

Okay this is just nuts for Sunday

Edited July 4, 2018 by Captain Shortwave

[Frosty.]

Great ukmo 12z if you love high pressure and temperatures in the mid / high 20's celsius range with the jet staying well to the north. The Gfs 12z also shows more very warm / hot anticyclonic weather this weekend and next week..Superb summer weather and no end in sight to it.

[I remember Atlantic 252]

19 minutes ago, shaky said:

First signs on the 12 gfs that the biscay low is further south and high pressure ridging back in!!its unreal!!hot temps continuing well into fi!!!madness!!

Yes, models trending away from Wimbledon finals breakdown, looks summery really all the way

[Weather-history]

I don't know if I'm imagining it but I swear that the "breakdown" is struggling on GFS to get within the 240hrs time period. Its like after 240hrs, the wall comes down 

[Winter80s]

Stunning again and models really deminishing a breakdown.  Hopefully it last until middle September until Hols are over.  

[mb018538]

Those arpege temps are all wrong surely....no way we’re seeing 33/34c out of this!

[Djdazzle]

6 minutes ago, mb018538 said:

Those arpege temps are all wrong surely....no way we’re seeing 33/34c out of this!

 I thought ARPEGE were normally pretty reliable?

[Man With Beard]

1 hour ago, Captain Shortwave said:

      

      

Onwards we go, no real change in conditions with high pressure in charge bringing lots of sunshine and only isolated afternoon showers, again the south could come under threat from a thundery low into week 2 but a lot could change there.

Temperatures continue in the same frame really, it looks very warm to potentially hot but nothing overly excessive in terms of heat or indeed the feel with humidity never being too high under that high. Just remember the sunscreen.

Obviously the dryness is probably the bigger concern now in my opinion as frankly rainfall look minimal to non existent.

It looks like 30C will be possible from tomorrow onwards for potentially a period of time that could exceed that of last week. Arpege showing a 30C across western parts of East Anglia tomorrow and the temperatures rising by a degree each day with the warmth spreading. This is possibly overdone???

      

 

Okay this is just nuts for Sunday

Yes I've also noticed it's overdone things post T48 before, but that would be a huge area to get wrong? 

[Frosty.]

The Gem 12z soon turns into a scorcher again with temps widely into the low 30's celsius across the southern half of the uk, really from this weekend and most of next week at 30 / 31 / 32c and possibly a few degrees higher in places..much hotter than the Gfs 12z shows. High pressure becomes the dominant feature for a while but then there's a hot humid thundery breakdown later next week.

[Mike Poole]

GEFS ensembles at T240, and the spread is still there from the blowtorch (P10), and those runs that keep the main heat much farther south e.g. P20, so various possibilities exist, depending on your preferences (well except Atlantic dominated rubbish!):

Edited July 4, 2018 by Mike Poole

[Man With Beard]

Sorry I'm not buying this ECM run. How on earth can it try to create a cold pool over the UK at T192 whilst under calm high pressure with no obvious northerly influence? 

Looking at the pressure charts alone, still looks pretty much like a heatwave from start to end 

[Frosty.]

Looking at the GEFS mean recently, mid July was the cut off period for this amazing summery spell but the 12z extends it more towards the end of the run, out to around the 20th July and even then the azores high / ridge is still lurking with intent just to the southwest but coming back to the reliable timeframe, the heat will build again from tomorrow and high pressure / strong ridging  will dominate the uk for many days to come.. so... much more hot dry sunny weather to look forward to but still a chance of the very high temperatures sparking isolated heavy showers / thunderstorms across southern / western uk at times and also a chance of a major plume towards the end of next week but the emphasis is on generally dry weather for most of the uk..the heat goes on!

 

 

 

 

[Mike Poole]

Well despite concerns expressed ECM makes it to T216 and is rebuilding the high pressure after a very settled and warm run:

But it doesn't last to the final frame, but that's day 10.  More runs still needed re the end of next week, but good through to then.

Edited July 4, 2018 by Mike Poole

[mb018538]

6 minutes ago, Mike Poole said:

Well despite concerns expressed ECM makes it to T216 and is rebuilding the high pressure after a very settled and warm run:

Looks like the opposite to me - between 144-240 hours the high is regressing back to the Azores, with the Icelandic trough slowly sinking SE’wards. Wouldn’t do much at that stage, but I can’t see high pressure rebuilding on that particular run anyway.

[Mike Poole]

6 minutes ago, mb018538 said:

Looks like the opposite to me - between 144-240 hours the high is regressing back to the Azores, with the Icelandic trough slowly sinking SE’wards. Wouldn’t do much at that stage, but I can’t see high pressure rebuilding on that particular run anyway.

Fair call, it was the weaker broken off high I was looking at and mistakenly, and as you can see on the T240 ^ it goes down hill.  Academic though at that range.  I'll believe some of these breakdowns when they have got to day 6!

Edited July 4, 2018 by Mike Poole

[Frosty.]

2 minutes ago, Mike Poole said:

 I'll believe some of these breakdowns when they have got to day 6!

Agreed, I'm very sceptical of any major pattern change occurring in the next few weeks, to me it's more of the same for the foreseeable future..i.e..generally very warm / hot dry and sunny bar isolated storms further s / sw and occasional very weak atlantic fronts brushing around the top of the high across the far n / nw.

[shaky]

57 minutes ago, Man With Beard said:

Sorry I'm not buying this ECM run. How on earth can it try to create a cold pool over the UK at T192 whilst under calm high pressure with no obvious northerly influence? 

Looking at the pressure charts alone, still looks pretty much like a heatwave from start to end 

Absolutely ridiculous how the uppers cool like that!!i was thinking the exact same!!anyway apart from that glitch lol its heatwave all the way to the end on the ecm!!let me know what the temps are like throughout that ecm 12z run mate!!much appreciated look forward to your update!!

[Mike Poole]

ECM ensemble mean at T144 and T240, in the reliable the ridge remains strong, at 10 days suggesting some of the members pull this back.  I still think any change to a more unsettled output has to show earlier than day 10 before it is worthy of any serious attention.

Indeed I'm trying (not always successfully) to focus attention on the 12 suite mainly at the moment because I don't think the situation is changing sufficiently quickly to overanalyse the runs twice or four times a day.

Edited July 4, 2018 by Mike Poole

[legritter]

Good evening Gang ,i have just got back from Canada ,having spent the last month there with my late Wifes very best friend who emigrated there in the very hot dry summer of 1976 ,crikey it was hot there on the last week ,30 miles north west of Toronto ,but beautifull air cooling ,like living in a fridge .well certainly looks like the heat will be building again from tomorrow ,great to be able to come on this weather forum which i,v said before ,The best i think in the world .as for the forecast Models ,in this sort of very unusual set up , and taking in to account most of the Northern hemisphere is in unusual Synoptics at present i would only look at the next week as a maximum ,but hey gang we need to enjoy all this heat , yes it could last most of the summer but it could flip ,which often is the case with extreme weather ,cheers gang ,nice to be back home ,

 

[mother nature rocks]

I have a funny feeling this ‘breakdown’ will get pushed back and back and back. We have seen it so many times before especially in winters past when milder air will apparently return for it to get pushed back.The block is in, the heat is here, it will take something quite substantial to remove this and for me at the moment the models just aren’t showing it!!!!! Heatwave lives on!!!!