model discussion Model output discussion 11th July onwards

[Allseasons-Si]

"THAT ECM" is a cracker!!!

[Frosty.]

15 minutes ago, Allseasons-si said:

"THAT ECM" is a cracker!!!

Indeed it is, and it ties in with my thoughts regarding the last third of august! ...I never thought next week would be anything other than mixed, it’s beyond that when summer will bounce back with a vengeance!...if I had any money I would bet on it..but I’m as poor as a church mouse who doesn’t have any cheese..but I’m still a happy guy...  !   ..at least I can afford the................. T internet! 

Edited August 12, 2021 by jon snow

[Allseasons-Si]

The ECM mean is another good run especially at day ten

[Frosty.]

Great minds think alike, wow we are good! .. ...

Just to add, I think it’s been very good in here today, friendly and fun with plenty of quality model discussion!...long May it continue!!!!  

[Uncle_Barty]

On 11/08/2021 at 17:46, Singularity said:

Worth noting that we now have a big negative mountain torque underway, following a big positive one.

 

Whats the difference between a negative and a positive nountain torque event?

I'd just assumed mountain torque events in general tended to contribute to a lower AAM.....

[Scorcher]

Looks like we're going to have to be patient but I think it's odds on that the high will move over us eventually- hopefully leading to a hot and sunny final week. Potential for something to develop like late August 2019 perhaps?

[summer blizzard]

Models agree on a cool and probably showery outlook to day 8 but at day 10 it is GFS vs GEM/Euro.

 

 

[MATTWOLVES 3]

Ec46 looking dandy...Heights building in more strongly overall...looks like we could be ending the month on a HIGH note..Low Pressure looks to be anchored towards the NW...But I would say many areas,and more especially away from the far NW could be seeing Summer out quite respectably! We didn't come into Summer all guns blazing,and it looks possible we won't be going out all guns blazing...just decent typical summertime conditions.

[Mike Poole]

3 hours ago, MATTWOLVES said:

 

@Mike Poole King of the 12z runs...come and bring us some cheer mate.

Late to the party today, folks, regular early evening pub session on Thursdays, since covid, so just getting round to look at the output.  But plenty to cheer about on the ECM and GEM T240:

Not so good on the others.  But the clusters look OK:

Just two on the T192-T240 timeframe. The first has the HP sat close but with a cool wind direction, the second and minority cluster has the HP drift east and has the potential for warmer scenarios and plumes.  

Bottom line, settled and dry incoming, nailed on.  Heatwave, plumes, thundery setups not…yet.  But a possibility, for sure, a slight one for now, but it is fun to watch and see if the signal develops…we will see…

[Frosty.]

The JMA 12h is looking good at day 11 for any fishing boats just to the south west of Ireland?!...  

Edited August 12, 2021 by jon snow

[Mike Poole]

Hey, liking this from the pub run T204:

Good in situ high, but power to add surely with that trough to the west. 

Edit T270:

Edited August 12, 2021 by Mike Poole

[JayAlmeida]

Seems like the GFS is back from it's little wobble this evening with the 18z but how many times has it teased this kind of African/Spanish plume to no avail? Next weekend looks closer to the ECM and GEM which is good enough for me and any ideas beyond that are in FI territory but atleast its moving in the right direction again.

Interesting visual indication of how far the hot air has to travel to reach us and why it can be such an elusive beast in the summer months 

 

The ECM 46 seems to be signalling a stronger HP signal for the next two weeks in line with the shorter range model output. Interesting to see that in week 1 It's centred to the north potentially setting up another bizarro N/S divide of sorts like we saw earlier in the summer. If we manage to pull up some real heat in week 2 we could all be in for a belter end to what has thus far been an underwhelming August.

W1

 

W2

Edited August 13, 2021 by JayAlmeida

[Methuselah]

Some serious heat-potential according to the GFS 00Z -- but, it doesn't really kick in until after Day 10. So, a bit of a 'Tom Jones' run:

    

    

    

[Frosty.]

I have a good feeling about late August just looking through the GEFS 0z, I think there would be some very warm anticyclonic weather punctuated by potentially hot & humid thundery incursions?...sounds good anyway! ⛈ ? 

[mb018538]

Looks like next weekend and beyond is still the preferred time for high pressure to properly make it to the UK.

ECM



GEM



GFS



Nice to see some consistency there, even if it is a good 9/10 days away until we may see the high properly move in.

Best 500mb outlook for a while, and we can see the easterly progression of the positive heights as we get toward the last week of August:




There is an interesting change from the ECM regime forecast though. The Monday update below was all blocking.....yesterdays update has the blocking lasting a week before all sorts of changes.

 

[Singularity]

Watching ensemble trends and considering the tropical / AAM developments recently summarised by Tamara, I have an increasing feeling that the final week of August will transport some of the currently exceptionally hot airmass to our south in our direction.

Thankfully it will likely have moderated a bit by then, while shortening days will further limit the potential heat in the UK. Still - if we got a direct hit (which I’m NOT saying will happen, just a plausible scenario), we could see summer 2021’s highest temps occur right near the end.

Personally, I’d rather we instead saw that hot air have an indirect influence by further inflating high pressure overhead to give us an extended dry and very warm spell. Also plausible .

Edited August 13, 2021 by Singularity

[Frosty.]

The longer term ECM 0z ensemble mean is looking preety good..roll on summer! ?  

 

[Captain Shortwave]

Looks like high pressure will take charge, though there might be a fair amount of cloud thanks to warm air toppling in and pressure tending to weaken through next week. However we could see the Atlantic trough reinvigorate later next week, which should allow heights to build more robustly through the U.K.

A second question is if we can get something like the day 10 charts to verify ,then how long this could sustain and how hot it could get. The operationals do suggest that conditions could become very hot across Iberia again, could some of this head this way?

[bluearmy]

Remaining on track 

all three ens on the same upper ridge page post day 9. Significant at that range and last seen ahead of the July warmth

[mushymanrob]

I wouldnt dust off the BBQ just yet, whilst high pressure is almost certain to develop next week so by next weekend and beyond its firmly in charge , the latest NOAA 8-14 day chart backs down from developing the eastward progress of the high, but instead starts to suggest itll be stalling North of the UK.

So settled, dry, but possibly on the cool side and the eastern coastal counties may well be poor with a northeasterly draft. The west though should be warm and sunny... whether this chart is a glitch or not will only become apparent with further runs, but unless the building high is centred to our East, theres no heatwave imho.

[Tamara]

On 13/08/2021 at 09:01, Singularity said:

Watching ensemble trends and considering the tropical / AAM developments recently summarised by Tamara, I have an increasing feeling that the final week of August will transport some of the currently exceptionally hot airmass to our south in our direction.

Thankfully it will likely have moderated a bit by then, while shortening days will further limit the potential heat in the UK. Still - if we got a direct hit (which I’m NOT saying will happen, just a plausible scenario), we could see summer 2021’s highest temps occur right near the end.

Personally, I’d rather we instead saw that hot air have an indirect influence by further inflating high pressure overhead to give us an extended dry and very warm spell. Also plausible .

The -ve mountain torque wavelength, impacting AAM tendency, we were discussing the other day is fully advertised in short to medium term modelling (up to about a week) which fits the envelope for periodicity (timespan) of such events if we include the time since its inception. You correctly observed recently how numerical models can get spooked by these events and their associated lunges in momentum (downwards in this case)

 

I expected continued gyration of the GWO around Phase 8 and back into the null phase based on the -ve inertia  of the upstream pattern - though the amplitude of this event, as indicative of the deeper Phase 8 orbit that has occurred is clearly greater than expected.

 

So, within the 7 day period to come, the advertisement of the anomalous ridge across the Atlantic and downstream trough across Scandinavia is fully concordant with the upstream -ve inertia within the Pacific creating the downstream retraction of the pattern - but equal to the actual diagnostic assessment( to the even greater extent than anticipated)

With this type of cross-analysis in mind ,I think its important to tie diagnostic wind-flow to the interpretation made by the representative upper air pattern of numerical modelling to illustrate at what point that parity is reached at any given time, so that people can see where the two tally, but also can get some idea  how the numerical modelling can also misread or under or over extrapolate such a given signal and which means that the two do not always tally quickly.

With the nearer term upstream pattern in mind, it puts the context of your latest quoted post into good focus relating to the anticipated recovery of momentum between days 8 and 10 and how enduring it might be and whether the models will be equally spooked by this event in the opposite direction of travel.   As the high frequency tropical cycle propagates eastwards, then the elastic band effect will come into being with quite a shunt to the downstream pattern as suppression wanes across the Pacific and de-amplification occurs here and transfers instead further downstream. As previously suggested, a dash of the GWO from Phase 8/0 across to Phase 4 would endorse the present indicated modelling at day 10 hence.

For the late August prospects for NW Europe, much hinges on both the strength and durability of recovery of momentum - with the anticipated prospect as stated previously that the low frequency walker cell will resume ascendency thereafter. and all that ensues in return of Atlantic ridge dominancy.

For me down here, always under the grip of intense sub tropical ridging right on the doorstep - its a case of just how hot, not for how long. However for NW Europe its very much a case of how (very) warm might it get and far how long in relation to the transfer of the ridge from west to east, allowing warm air advection from the south, before the pattern breaks down once again much as it did in July. This type of anticipated rinse and recycle was mooted in a previous post.

But at present, a similar reprise of the July fine spell for the UK looks a reasonable expectation.

[Frosty.]

It’s another good Gem in the mid and especially longer term, the 0z becoming increasingly settled / anticyclonic and temperatures really responding further ahead as we import a continental flow!...I think summer is coming!!!!!!!!!!?...  

 

Edited August 13, 2021 by jon snow

[MATTWOLVES 3]

43 minutes ago, jon snow said:

It’s another good Gem in the mid and especially longer term, the 0z becoming increasingly settled / anticyclonic and temperatures really responding further ahead as we import a continental flow!...I think summer is coming!!!!!!!!!!?...  

 

Only problem is mate,you've been saying Summer is coming since May

The 6Z mean continues the trend of a more settled outlook,and eventually warms us up a notch! I'm thinking some very decent Summer type conditions,with temps ranging from Low to Mid 20s....thats very acceptable I would have thought for many on here.. Im not convinced of a repeat of mid July though! Tbh I'm not that bothered about it,sunny and settled and rather warm would do me a treat...but each to there own...

We can't rule out a Hot spell completely for obvious reasons,but I think it would be very short lived even if it was to occur! 

The outlook looks decent though for sure,so you can't complain when the missus tells you to sort out the garden now! Mind you......you could always do a cheeky sly off to the pub!

And just as I play down the heat...the met bring it back up by including a possible Stly and very warm come months end...then a possible Estly towards the South! Petty it's not January

Edited August 13, 2021 by MATTWOLVES

[Methuselah]

Nae bad, from the GFS 06Z:     

                                                      

Op or control?               

[Methuselah]

GFS 12Z: