Model Output Discussions 12z 01/06/2017

[knocker]

A very unsettled prognosis from the ecm this evening

The first low duly arrives over Ireland by 12z on Friday with the fronts aligned down the west coast of the UK. These  track east ensuring a pretty wet and windy couple of days for most. The low also tracks slowly east and is in the North Sea and clear of the UK by 12Z Monday.

The Azores now briefly ridges north east but by midday Wednesday the next quite intense upper low has left Canada and is south west of Iceland and the surface fronts associated with this are impacting the north of Britain with a fair amount of rain. They and the rain duly sweep south east across the rest of the country through weds into Thursday  By Friday they have cleared away leaving the country in a brisk NW airstream, the main low is near the Faeroes, with copious showers mainly confined to north of the Midlands

During all of this the next Upper trough has been progressing east across the Atlantic and the surface low associated with this has tracked rapidly ENE to be just NW of N. Ireland by the end of the run.

[blizzard81]

7 minutes ago, knocker said:

A very unsettled prognosis from the ecm this evening

The first low duly arrives over Ireland by 12z on Friday with the fronts aligned down the west coast of the UK. These  track east ensuring a pretty wet and windy couple of days for most. The low also tracks slowly east and is in the North Sea and clear of the UK by 12Z Monday.

The Azores now briefly ridges north east but by midday Wednesday the next quite intense upper low has left Canada and is south west of Iceland and the surface fronts associated with this are impacting the north of Britain with a fair amount of rain. They and the rain duly sweep south east across the rest of the country through weds into Thursday  By Friday they have cleared away leaving the country in a brisk NW airstream, the main low is near the Faeroes, with copious showers mainly confined to north of the Midlands

During all of this the next Upper trough has been progressing east across the Atlantic and the surface low associated with this has tracked rapidly ENE to be just NW of N. Ireland by the end of the run.

Days 5 to 7 look to be a fair improvement compared to the last couple of runs. Let this be the trend and who knows, the azores high may ridge in even stronger by the time we reach that point.

Edited July 19, 2017 by blizzard81

[Frosty.]

6 minutes ago, blizzard81 said:

Days 5 to 7 look to be a fair improvement compared to the last couple of runs. Let this be the trend and who knows, the azores high may ridge in even stronger by the time we reach that point.

Agreed, I didn't think the Ecm 12z looked too bad, at least further south. There is some decent weather on that run.

[blizzard81]

3 minutes ago, Frosty. said:

Agreed, I didn't think the Ecm 12z looked too bad, at least further south. There is some decent weather on that run.

Yep, as always it's about trends and that 5 to 7 day timeframe is still far enough out to see more improvements. 

[knocker]

16 minutes ago, blizzard81 said:

Days 5 to 7 look to be a fair improvement compared to the last couple of runs. Let this be the trend and who knows, the azores high may ridge in even stronger by the time we reach that point.

The difference at day 5 from the previous run is that it just shifts the weekend low east a bit quicker. And I've already post the analysis for day 7 with the ridge well and truly squashed with an 130kt jet blowing into southern Ireland, so if you can spot an improving  trend out of that you are a better man than me Gunga Din.

Edited July 19, 2017 by knocker

[Frosty.]

6 minutes ago, blizzard81 said:

Yep, as always it's about trends and that 5 to 7 day timeframe is still far enough out to see more improvements. 

Yes and the Ecm is an improvement on the 00z, considerably so..hopefully the Azores high can build in again in the not too distant future and we can enjoy more spells like the last few days.

Edited July 19, 2017 by Frosty.

[Man With Beard]

7 minutes ago, knocker said:

The difference at day 5 from the previous run is that it just shifts the weekend low east a bit quicker. And I've already post the analysis for day 7 with the ridge well and truly squashed with an 130kt jet blowing into southern Ireland, so if you can spot an improving  trend out of that you are a better man than me Gunga Din.

I think with the jet the way it is forecast, the "percentage play" is on the Atlantic low crossing all of the UK by next Friday at the latest. Of course, the jet forecast could be wrong, but I doubt it will be wrong enough to miss us by much. But Monday to Wednesday, or even Thursday - well, if the form of the summer is repeated, I don't see why some warmer weather couldn't return to all parts for a while. Best not speculate much further!

[knocker]

9 minutes ago, Man With Beard said:

I think with the jet the way it is forecast, the "percentage play" is on the Atlantic low crossing all of the UK by next Friday at the latest. Of course, the jet forecast could be wrong, but I doubt it will be wrong enough to miss us by much. But Monday to Wednesday, or even Thursday - well, if the form of the summer is repeated, I don't see why some warmer weather couldn't return to all parts for a while. Best not speculate much further!

Well actually my first post was not speculation, I tend to leave that to others unless stated, but was just my take of this evening's ecm output with a little detail thrown in. People are quite entitled to disagree with my post but a little detail to support any argument would be appreciated. And I'll repeat, because I find this quite important, to talk of possible trends from some transient ridging lasting a couple of days in a pattern that is very mobile on a det. run with nothing else to support it is to say the least very misleading. IMO of course.

And the jet is the way it is forecast because of the pressure distribution in the Atlantic and thus the position of the strong thermal gradient.

Edited July 19, 2017 by knocker

[Singularity]

Next week Tue-Fri may be one of those occasions where a low breaking away from the westerlies and dropping down somewhere near the Azores could lead to a transient (assuming background signals remain against a sustained eastward Azorew High displacement) very warm or hot spell at short notice. 

Only faint signs so far that such a feature could turn up, but they are out there.

At least that gives us something to watch out for in hope. A straw to clutch  .

[northwestsnow]

Well ecm seems consistent to my eyes, the ridge does look ever so slightly more robust early next week but the jet is still going to blow it away...i honestly thought the Atlantic would be getting quiter by late july..

[Fourty Point Three Degrees]

A miserable outlook according to Ben Rich on the beebs WFTWA, according to him theres no ridge next week and the low remains over and across the UK.  http://www.bbc.co.uk/weather/

[Man With Beard]

39 minutes ago, knocker said:

Well actually my first post was not speculation, I tend to leave that to others unless stated, but was just my take of this evening's ecm output with a little detail thrown in. People are quite entitled to disagree with my post but a little detail to support any argument would be appreciated. And I'll repeat, because I find this quite important, to talk of possible trends from some transient ridging lasting a couple of days in a pattern that is very mobile on a det. run with nothing else to support it is to say the least very misleading. IMO of course.

And the jet is the way it is forecast because of the pressure distribution in the Atlantic and thus the position of the strong thermal gradient.

Ah, I realise I worded my post wrongly. I was talking to myself about not speculating further ahead - not intended as a comment on your post - sorry!

[knocker]

The anomalies this evening are in pretty good agreement.

Low pressure over the Arctic with associated trough south west of Iceland with a conduit to the trough to the east of the UK. The ridge orientated around the north of Scandinavia into eastern Greenland is probably not doing us any favours as it appears to help tighten the Atlantic gradient, Thus a westerly upper flow with a strong jet running west-east and the Azores not showing to any significance all portends an unsettled period with the temps no great shakes. As ever the usual caveats apply so this doesn't mean a complete washout and the det runs will sort in the next two or three days.

[blizzard81]

Another positive trend from tonight's ecm is that temps will be a notch higher next week when compared to the previous couple of runs. Ecm ensembles for London clearly show this for Tues to Thurs next week when compared to the 00z ensembles. 

[mb018538]

Those anomalies show the Azores high massively kicked into touch. Trough extending right across the Atlantic preventing any ridging. I'm starting to get a bit worried my holiday in Norfolk on the 29th is starting to look very dicey!

[Man With Beard]

The pub run trying to provide some cheer. Temperatures back into the mid twenties widely next Tuesday and maybe upper twenties on Wednesday in the SE.

Why always Tuesday and Wednesday???

Edited July 19, 2017 by Man With Beard

[Fourty Point Three Degrees]

17 minutes ago, Man With Beard said:

The pub run trying to provide some cheer. Temperatures back into the mid twenties widely next Tuesday and maybe upper twenties on Wednesday in the SE.

Why always Tuesday and Wednesday???

Well do we or don't we want decent weather and a trough free week next week? Yet when a decent upgrade appears it just gets thrown back into GFS's face and accused of being a 'pub' run. Well I'm happy with what its showing, no complaints from me,  gotta clutch any straw possible at this rate. Brilliant upgrade on previous runs and so was ECM!! Lets hope they keep up the good work!

[knocker]

Pretty much what one would expect from the gfs this morning in this pattern. unsettled in the ten day period with the usual NW/SE bias. Three of four 'trends' are discernible albeit the pressure distribution is such that the strong jet ( around 100kts) leaving the Eastern Seaboard is never far from out shores next week.

Currently low pressure covers an area south of Iceland running south east to the low countries and the cooler air is already into the UK which is quite noticeable after the recent humid conditions. Any frontal rain will soon clear today and the next low is over the Irish Sea by 12z tomorrow with fronts already impacting the south west. Thus a pretty wet couple of days with frontal rain and showers the latter becoming less frequent on Sunday as the low fills and tracks east into Denmark leaving the UK in a light northerly with the showers probably confined to the coastal areas.

The aforementioned transient ridge duly continues to push in, albeit some light showery rain in the west on Tuesday but by 12z Wednesday the next upper low has arrived south of Iceland with the associated fronts from the rather deep surface depression already bringing strong winds and rain to the north west.

In the next 24 hours te the fronts track south east weakening as they go clearing Kent by Thursday evening. Again some brief ridging into the south (familiar story?) before the next low rushes into Scotland on Saturday bringing wet conditions to all accompanied by possible gales on western coasts in the strong westerlies. Not to worry too much about the detail at this stage as that is a long way off given the current fluidity of the pattern

No significant change with the GEFS anomaly this morning so I must leave it to others to spot the brilliant upgrades which is a completely unnecessary way of commenting on the outputs in any case

 

Edited July 20, 2017 by knocker

[mushymanrob]

theres NO quick way back to heat if this chart is to be believed, whilst next wednesday is looking ok, especially in the southeast, the general outlook is poor, below average, and with no sign on any route back to something that would produce aengthy hot spell, the writing must be on the wall for at least the first half of august.

 

[northwestsnow]

Just now, mushymanrob said:

theres NO quick way back to heat if this chart is to be believed, whilst next wednesday is looking ok, especially in the southeast, the general outlook is poor, below average, and with no sign on any route back to something that would produce aengthy hot spell, the writing must be on the wall for at least the first half of august.

 

Horrendous.At least mon and tue look dry though after that its another deep Atlantic low winging in and the green circle of despair with accompanying yellows and oranges over Greenland..

[knocker]

The models have been playing around with the idea of quite a deep low next week (leaving aside explosive cyclogenesis) and they are still toying with the idea this morning.

Anyway before that the ecm has the weekend low somewhat slow to fill and clear the UK completely and at 12z Monday it is still influencing the east coast with a little cool northerly surge. From here brief transient ridging takes place but by 12z Wednesday the next deep upper low has arrived to the north west and the fronts from the similarly intense surface feature are just to the west of Ireland.These fronts traverse the UK Wednesday night clearing the south east by early Thursday afternoon. Meanwhile the main low has tracked ESE and by 12z Friday is over the Hebrides bringing with it rain and gales, particularly in the north and west.

[mb018538]

What the hell?? A 960mb atlantic low in July.....I mean really. It's not December for crying out loud!! ECM also starts to run with the northern blocking I mentioned last night....on a slippery slope if that starts to happen!

[blizzard81]

My thoughts more or less the same as yesterday. A nice couple of days for most next week. Unfortunately a 'trend' now for the models to really blow that atlantic low up. They have been toying with this idea for the last couple of days but now seem to be going for it. Still time for the track and intensity of this storm to change though and any changes will have huge ramifications with regards to the weather we experience. 

[Summer Sun]

ECM going all Autumnal must be the school holidays...

 

Edited July 20, 2017 by Summer Sun

[Man With Beard]

Now we're into a pattern that the models are usually more accurate with, I feel comfortable to speculate out to D8. An unsettled weekend, then a rather better couple of days next week with the mid-20s likely again, before fronts cross the country from north to south Wednesday into Thursday. And then this for next Friday: 

    

I can't see anywhere escaping the effects of the low, but the questions are over the strength of the wind in the west, and whether the south might escape the worst of any wet weather.

The ensemble mean charts sit somewhere between the most northerly and southerly extents:

  

Another unsettled weekend for most, then, is the most likely outcome. 

To early to guess beyond that - current data suggests that the following week could either lift the trough (=more warm sunshine) or reinforce the trough (=more cool rain) - or even more likely, alternate between the two.

I did see suggestions from the NOAA that settled weather is very unlikely, but I think we need to wait for it to settle down a bit - its current 6-10 day chart shows developments that the corresponding 8-14 day charts did not see at all (compare below):