Model output discussion - hot spell beckons but then what?

[knocker]

10 minutes ago, Downpour said:

 

Yes good shout on this earlier. It didn’t look plausible and you nailed it. Bank hol weekend looking pretty decent with the Saturday probably the best day of the three. 

Actually I don't think anything is nailed yet Downpour. A quick glance at the ecm subsequent Monday and more amplification. Purely just to be noted

[Mike Poole]

So to that question at T144, there's clearly a gap in the high pressures with the UK solidly in it, ECM ensemble mean would suggest that it is more likely to be a lesser feature:

[feb1991blizzard]

Signs of a potential Cool NW flow as we end the month.

 

Edited August 19, 2019 by feb1991blizzard

[Singularity]

Huge fluctuations going on with regard to how much of a trough extension there is messing with the BH weekend weather.

Nice to see further scope for very warm weather well into the following week, regardless.

Thought for fun: The ECM 12z later stages aren't all that far away, in the grand scheme of things, from a late Sep 2011 setup. Sadly, we don't have a souped-up MJO to facilitate such an extreme setup within the next 10 days, so it's an unlikely event for the closing days of Aug 2019. Indeed, it seems the flow could just as well be coming from the opposite direction if FV3 has its way.

[Frosty.]

According to tonight's Ecm 12z ensemble mean, southern uk, especially further s / se can look forward to a return of summer!!

 

[Mr Frost]

32 minutes ago, JON SNOW said:

According to tonight's Ecm 12z ensemble mean, southern uk, especially further s / se can look forward to a return of summer!!

 

I don’t think Summer has ever left the SE mate - best place to live in the UK and Ireland this time of the year if you want warmth/heat/sunshine. (Which I do! )

Pretty dismal up here in the West of Scotland - full blown Autumn conditions the last few days. 

Just browsing through the charts/models for the first time in a while and this is the best I can muster up for here.

The only thing resembling Summer around here are the sunsets which never fail to deliver. (Wee picture from tonight to brighten up the thread!)

Have a good night everyone and I really do hope we see a UK and Ireland warm/hot/sunny spell soon! (If that is the type of weather you prefer! If not come to the West of Scotland for a daily fix of 16c, blustery cool wind and endless showers! )

Edited August 19, 2019 by Mr Frost

[Andy Bown]

2 hours ago, knocker said:

But given the lack of interest in the thread there doesn't seem much point in making the effort tp post anything

Then you would be very wrong. 

[DR(S)NO]

3 minutes ago, Andy Bown said:

Then you would be very wrong. 

Agreed Andy. I rarely post but very much look forward to reading posts by others. I certainly appreciate the time, effort and enthusiasm...and also the chance to learn from some very knowledgeable posters.

[feb1991blizzard]

31 minutes ago, Andy Bown said:

Then you would be very wrong. 

Anyway - if your bored, you can always look at this Model Output Discussion thread of course.

 

 

 

Edited August 19, 2019 by feb1991blizzard

[knocker]

Outlook - A N/S split developing over the next few days

The North Atlantic 50mb and surface analysis for midnight

The last vestiges of the low pressure that has been in charge for the last few days will disappear today as the showers in the vicinity of the occlusion in the north slowly dissipate but a trough preceding the warm front, associated with the complex low to the north west, will bring some showery outbreaks to the north east during the afternoon. And rain from the aforementioned warm front will effect N. Ireland by 1800. Sunny intervals elsewhere

The showery activity on the warm front will move north east through the evening and overnight with the south of the country remaining dry.

The warm front clears on Wednesday leaving much of the country in a an increasingly windy warm sector as the Atlantic gets into gear to the west.Thus initially sunny intervals and showers but a band of moderate rain associated with the cold front will effect N. Ireland by midday and move east effecting much of Scotland and NW England by 1800.

The weakening cold front tracks south east down the country on Thursday so sunny intervals with some showery activity but a lot is happening in the Atlantic as the upper troughs merge with an additional 'feed' down the Denmark Straits. And another frontal system from this complicated arrangement brings continuous rain to N. Ireland and western Scotland by 1800 accompanied by quite strong winds

Friday sees the realignment of the upper trough to the west as the subtropical high zones start to amplify with a ridge developing across the south of the country with an associated rise in temperature. Still some showery rain in the courtesy of an occlusion and still breezy

By Saturday everything has moved a tad east with a very slack gradient over the UK so quite sunny in most areas with the temps still on the increase. But still some bits and bobs of rain in northern Scotland from a trailing front.

 

Edited August 20, 2019 by knocker

[knocker]

The $64,000 question is where from here?

According to the gfs the weak upper trough tracks east over Sunday and Monday but by then a new upper low has tracked east to be over Iceland and this impacts the northern half of the country

For further comment I will just settle on the fact that the new trough becomes quite influential over the later half of the ten day period

[Methuselah]

GEFS 00Z ensembles okay until August 26; after that, though, things still look very undecided...

   

   

But, given the fact that no substantial loss of SLP is progged, the uncertainty belongs more to the precise location of an anticyclone than to any drastic change in synoptics...? In the meantime, it's another day on the farm, for me!

[knocker]

The ecm is predicable different to the gfs and it's basically down to further amplification and the development of the Atlantic trough and the subtropical high.

So the surface analysis similar to the gfs on Sunday but varying for the better on Monday and getting quite warm. But the detail still a fair way from being nailed

 

Edited August 20, 2019 by knocker

[knocker]

It will be quite interesting to see how the EPS goes in the longer term this morning as last evening it tracked the positively tilted Atlantic trough east to be more neutrally aligned over the UK as the ridge was shunted east,

In the meantime I'm down to see young Sidney

Edited August 20, 2019 by knocker

[northwestsnow]

Well EC  is nearly enough to bring me out posting again !! :

I mused earlier in the month about the likelihood of Summer weather in Sept but if EC is to believed, i might have been a week or so out with my timing.

Thur/fri/sat look lovely for many, i suspect the 120-144 timeframe is far from 'nailed' though,EC det could be one of the 'better' solutions thereafter and could be barking up the wrong tree, so to speak.

[Summer Sun]

UKMO and GFS both go for a deep low near Iceland on Monday a decent day for the UK but the low will be crucial for how the end of August plays out. ECM doesn't have it so deep and thus keeps the high pressure going

GFS eventually sees the low having more of an influence in our weather by forcing the high away where as ECM keeps the high pressure going

Much to be resolved still beyond Monday a decent weekend ahead for the majority after some rain over the next couple of day's in the north then all eyes on the low and how our summer will end

[mb018538]

52 minutes ago, knocker said:

The ecm is predicable different to the gfs and it's basically down to further amplification and the development of the Atlantic trough and the subtropical high.

So the surface analysis similar to the gfs on Sunday but varying for the better on Monday and getting quite warm. But the detail still a fair way from being nailed

 

I’d say the main difference is that the ECM develops an Iberian trough - this supports the high and promotes the warm SE flow.

[Man With Beard]

Finally feeling more confident about a cracking bank holiday after seeing this morning's ECM - I haven't much experience of ECM raw data vs actual at this stage is summer, but with raw temps 28/29C by the latter stage of the bank holiday, I'd be thinking just above 30C somewhere on any of Sunday, Monday or Tuesday? I think that might count as heatwave quality weather

Edited August 20, 2019 by Man With Beard

[SMU]

Looking quite close to the september analogues

 

It will be very interesting to see if we lose the -NAO in Sept in favour of the above^

Looks good for now..

[Singularity]

To split or not to split?

That’s the Sat-Sun question; ECM and UKMO split away a low to become cut-off to our south or southwest and lock in a very warm or hot airmass across much or all of England & Wales, but FV3 sees no such separation, taking that low out to the ENE and making to harder for E&W to hold onto settled weather with high temps for late Aug.

[shaky]

14 minutes ago, Singularity said:

To split or not to split?

That’s the Sat-Sun question; ECM and UKMO split away a low to become cut-off to our south or southwest and lock in a very warm or hot airmass across much or all of England & Wales, but FV3 sees no such separation, taking that low out to the ENE and making to harder for E&W to hold onto settled weather with high temps for late Aug.

Going for ecm and ukmo right now!!especially cos the changes have happened at an earlier timeframe on the ecm!!the gfs has really been all over the place last few days!!i really have lost all confidence in it to be honest!i think the old gfs was better but even that was kinda bad lol!!the gfs has gone from trough over us  for the weekend to high pressure which ecm and ukmo have been pretty consistent barr maybe the odd run!!its that slow creep back towards the euros that it normally does!

[mb018538]

ECM this morning sits right at the top end of the ensemble for 850s, just about top end/outlier for slp, but is an outlier for 500mb heights. Probably not too surprising given how warm/hot it is. Still lots to be resolved with that trough as mentioned in other posts.

[shaky]

5 minutes ago, mb018538 said:

ECM this morning sits right at the top end of the ensemble for 850s, just about top end/outlier for slp, but is an outlier for 500mb heights. Probably not too surprising given how warm/hot it is. Still lots to be resolved with that trough as mentioned in other posts.

Yeh probably wont be as hot as ecm but not as pessimistic as gfs!!i think ukmo middle ground solution is perfect and is still hot and sunny for most

[legritter]

1 hour ago, knocker said:

It will be quite interesting to see how the EPS goes in the longer term this morning as last evening it tracked the positively tilted Atlantic trough east to be more neutrally aligned over the UK as the ridge was shunted east,

In the meantime I'm down to see young Sidney

Hope we will be seeing more of young sidney .three months from now hey it could be the beast from the east ,with no food in the cupboards ,and queuing for all sorts of things , but back on topic our warm weather as predicted by todays charts will be most welcome ,cheers get the STellas out .

[Singularity]

44 minutes ago, shaky said:

Going for ecm and ukmo right now!!especially cos the changes have happened at an earlier timeframe on the ecm!!the gfs has really been all over the place last few days!!i really have lost all confidence in it to be honest!i think the old gfs was better but even that was kinda bad lol!!the gfs has gone from trough over us  for the weekend to high pressure which ecm and ukmo have been pretty consistent barr maybe the odd run!!its that slow creep back towards the euros that it normally does!

http://mikeventrice.weebly.com/hovmollers.html

I think GFS/FV3 has been struggling with the zonal wind evolution across the Central Pacific. It was seeing a total 'revenge of the trade winds' (blue shading), but has now corrected toward a more even battle between those and anomalous westerlies. It's a very mixed situation, so confidence in all modelling is below normal, but I do feel that the notion of ridges across the UK holding on a good way into next week has plenty of merit.

On the side - the powerful WWB (deep orange shading) within approx. 10-30*W i.e. the central to eastern tropical Atlantic is an interesting anomaly. Looks related to a Kelvin wave moving through the area, which should promote tropical cyclone genesis during the next fortnight. So far, this August has been notable for a total lack of significant ex-tropical influences on the N. Atlantic pattern.