Model output discussion - summer rolls on

[Man With Beard]

2 minutes ago, weirpig said:

Ecm continues the warmth  slight blip then heat returning next week  perhaps favouring the West more so this time with the run ending with uppers of 16 encroaching on the south west  possible mid thirties towards the end of the run 

Sounds about right. Not much internet where I am this week so won't be many posts from me, but checking out the latest EC clusters, still looking generally like a plume very possible again next week (never take notice of a GFS wobbly until other models join in). And of course very hot this week. Enjoy / Endure! 

[Guest Delete Me]

What uppers are we expecting rolling into the start of August, and will we see 35c+?

[SMU]

Another run at the UK record on the ECM- certainly day 10 & day 11 Heading for the High 30s

Bone dry as well....

[Frosty.]

Just a tiny blip at the weekend from the Ecm 12z but the recovery next week is impressive back to the heat ..just a mention about this friday..now that's what I call a very hot climax!!

Edited July 23, 2018 by Frosty.

[Man With Beard]

4 minutes ago, Steve Murr said:

Another run at the UK record on the ECM- certainly day 10 & day 11 Heading for the High 30s

Bone dry as well....

Definitely still on imo. Certainly mid 30s

[Captain Shortwave]

Just a couple of comments on the ECM.

1) Surprised to see it further west than the others for Friday and this really is telling as the temperatures are higher for Friday than the currently very hot Thursday (Yes 35C would be possible but with the caveat that thunderstorms coulds be breaking out as a surface low develops across SE England into Belgium and Northern France).

2) I always feel dubious when model output wants to direct warm air advection towards Greenland around that low, the end result almost always ends with a vertical or slight positive tilt to the ridge.

Not really buying this solution though the surface conditions over the UK are not drastically affected.

This looks a better fit to me, the ECM actually ends up with a swave of heights over the mid-latitudes from the Atlantic, across the UK and into northern Europe, this caused by the jetstream pushing through the huge ridge to our north east earlier along, again I suspect the ridge to our east will be more amplified than what the ECM is showing for week 2.

[Summer Sun]

1 hour ago, CreweCold said:

After being evident run after run, it's good to see that 'hump' of high 850s being brought down a touch on the 12z GEFS (around the 3rd August)

Hoping the 18z can carry on with the downward trending of the mean. Op and control on a similar page also.

ECM not interested yet maybe another surge of heat into early August

[Methuselah]

Well, given that most of the models are suggesting some sort of SWerly flow for tomorrow, it's possible that somewhere in the region of RAF Mildenhall might exceed 34C...? It reached 35C way back in August 1973.

[Singularity]

Well it was a strange experience watching that 12z GFS roll out earlier. So much so that I'm going to provide some details, for entertainment value:

 

Here at +168, the 12z on the right compared to the 06z on the left has a more conducive jet stream alignment to building the Scandinavian blocking high closer to our shores over the following few days, as the jet up the western flank of the block is stronger (better warm air advection aloft) and the jet to the SW of the UK is diving more to the south.

  

Yet just two days later the blocking high seems to be just falling apart in-situ on the 12z run (middle chart), and a very peculiar section of flat jet stream has manifested in the N. Atlantic. I've never seen that manner of jet occur in a location with only a weak trough in position (rightmost chart). The 06z had the more natural (for weak troughs under +AAM regime) buckled jet and maintenance of the blocking high E and NE of the UK. It makes the difference between the blocking high persisting to day 10 and beyond and it being 'punctured' by the jet stream, leading to a (probably too rapid on this run anyway - it is GFS after all) capitulation with a more westerly upper flow taking over to our NE.

Perhaps it was just a fluke run, with the misjudgement of the mid-Atlantic profile setting off a chain reaction - chaos theory in all its glory. Time will tell, but I'd be stunned if it wasn't, given the strong misalignment with the tropical forcing at play.

 

To be fair to it though, all of the models are finding more westerly progressiveness and SW-NE ('semi-zonal', you might say) alignment to the troughs than could be expected with the +AAM background and eastward MJO propagation, likely due to their ongoing struggle at resolving the latter.

I mean just look at this. Day after day, the EPS mean (shown as ECMF) seeks to kill the MJO off, and yet apart from a brief pause on 18th, the MJO has propagated eastward.

So what about today?

Another move east and a gain in amplitude!

Honestly, this is the worst model handling of the MJO that I've witnessed since I started paying close attention during the winter of 2009/10. I believe it's a case of atmospheric inertia being underplayed against a Pacific tropical SST pattern that's only weakly supportive of the propagation. Perhaps this is where tight isobar's confidence has had some roots...?

It may be too late for this MJO calamity to have much effect on the track of the Sun-Mon trough, but it might be enough to keep the S and SE under very warm or quite hot conditions (edit: just checked the rainfall charts for the ECM 12z and it has the front reaching all but the far southeast corner having already brought some intermittent rain to much of the south on Sunday afternoon! A shocking result given the signals but as CS alludes to, the trough evolution is dubious. You never know though!). I expect we'll gain a good idea about that within the next few days. Then... we'll see. I'd not entirely mind being wrong in that I could then enjoy something more akin to the May-June pattern of ridging from the southwest with relatively comfortable temperatures, but it would feel like an affront to teleconnection theory (tropical forcing is now very different to what we had May-June!) so I'm very divided in opinion!

 

Regardless of the outcome, it's been very interesting and educational watching these models take on a combination of changing upstream forcing and unusual amounts of hot air amassing over the near continent, and I expect this will continue to be the case for a while longer yet .

Edited July 23, 2018 by Singularity
There's always one!

[mushymanrob]

flicking between the two 8-14 day 500 mb charts would suggest the weakening of the atlantic trough with a slight retrogression , with the eastern ridge becoming slightly stronger still .  this has got to lend more weight to the hotter operational runs , with more southerly sourced air then westerly.

the hot dry weather looks set to continue into early august, with these consistent, mean upper charts having a certainty value of 4/5.

[Mike Poole]

Keep your eye's  peeled for the weekend 4/5 August, GEM has heat primed and ready, where's this lot going?

ECM has this figure hunkering down too, where's this going:

Time of interest just beyond many of the models, but it will become in range in just a day or two! 

[Frosty.]

I think this is a really encouraging T+240 Ecm 12z ensemble mean this evening compared to recently..signs it will be hotting up again from the south..like the earlier op showed! 

Edited July 23, 2018 by Frosty.

[Singularity]

Signs of what looks like elevated storm activity Thursday night on the NW flank of a shallow low moving NNE out of France.

ECM and ARPEGE also have this feature. The elevated activity diminishes as it crosses CS England but then surface-based activity takes over as it crosses the increasingly hot air across eastern England. Timing relative to daytime heating will be crucial with that part. 

Looks like the best chance so far this month for 1+ mm of rain over CS England. Now just watch it correct east .

[Djdazzle]

Still no agreement from the models for Friday. At this range, it’s getting silly!

[Mike Poole]

A significant Scandi block forming.  Take something to take this one out, I think!  Tropical storm maybe, oops we've just had one!  ICON running into the brick wall at T120:

 

 

[DIS1970]

This heatwave lark seems a bit overcooked at the moment, current charts locally suggest, Thursday is the only day reserved for any temp above 80f, the South-east and Eastern England appear at the moment to be the area's likely to kop any severe heat.

[Mike Poole]

GFS 18z, stage set at T240:

For the surge at T288:

 

[Guest]

For what it's worth, the 18z brings back the idea of a hot plume during the first weekend in August, an idea temporarily abandoned by the 12z. We'll be teased on this potential outcome throughout this week!

[East_England_Stormchaser91]

16 minutes ago, DIS1970 said:

This heatwave lark seems a bit overcooked at the moment, current charts locally suggest, Thursday is the only day reserved for any temp above 80f, the South-east and Eastern England appear at the moment to be the area's likely to kop any severe heat.

It’s been going on since May/June. I think remarkable is an understatement. If you spread this over a summer average, I think it could remain in the history books for a very long time indeed. 33.3c reached today, and from what I’m going by, there’s every potential of the 90F mark being breached every day this week somewhere. If this isn’t enough, then the start of August is looking like it could well be. Every bit of potential that we could be threatening the all time UK record. 

[summer blizzard]

GFS18z is indeed a hot run late in FI and again very messy and humid. 

Personally (as i am now done with this) i would like to see the day 10 Euro come to fruition. The Atlantic is far too weak and in the short term pressure is high over the UK however we have more or less lost high pressure over Europe and probably later on the UK.

[Paul]

Can we stick to the models in here please, there are plenty of other places on the forum to chat about the summer/heat/drought more generally.

[Frosty.]

Good news from the 00z runs, following a less hot fresher blip at the weekend, next week hots up again, the Ecm 00z looks as hot as some of us are seeing this week..the message is, the heat will return next week, especially further south!☺..in the meantime, enjoy this week's HEAT!

Edited July 24, 2018 by Frosty.

[I remember Atlantic 252]

Monday a poor day, hope that changes  but weekend looks good

17 degrees, what the hell!

Edited July 24, 2018 by I remember Atlantic 252

[Midlands Ice Age]

Anyone else notice the difference in temperature across Finland and easpescially NE Russia as shown below in 2 posts just one hour apart?.

 

-5 850's on the one by Liima and +20 on the one by Mike Poole ……….

Probably represents a 30 - 40 degree difference at the surface.

(and we think our weather forecasters have problems!!!)

9 hours ago, Liima said:

For what it's worth, the 18z brings back the idea of a hot plume during the first weekend in August, an idea temporarily abandoned by the 12z. We'll be teased on this potential outcome throughout this week!

 

9 hours ago, Mike Poole said:

A significant Scandi block forming.  Take something to take this one out, I think!  Tropical storm maybe, oops we've just had one!  ICON running into the brick wall at T120:

 

 

 

 

 

Edited July 24, 2018 by Midlands Ice Age

[Summer Sun]

1 hour ago, I remember Atlantic 252 said:

Monday a poor day, hope that changes  but weekend looks good

17 degrees, what the hell!

Looks like a fresher blip for a few day's ECM also shows this but signs are for a renewed surge of heat later next week

Edited July 24, 2018 by Summer Sun