Model Output Discussions 12z 01/06/2017

[Evening thunder]

Hang on.. it's one morning of model runs which you could say are about as likely as last nights runs.. the GFS ensemble mean looks nice still. I'm sure all the positive signs discussed yesterday haven't evaporated overnight and it could still improve in the 2nd half of July as the Met Office outlook still goes for, even if doesn't suddenly appear on the 15th (the outlook does currently suggest towards the end of the 6-15 day period).
It's not certain of course though, as always.

Edited July 10, 2017 by Evening thunder

[knocker]

No  significant changes with the ecm output except it is suggesting quite an intense low to rush in from the south west early next week which would bring some quite inclement weather and possibly some strong winds to the north. As it is at that range merely to be noted at the moment.

Edited July 10, 2017 by knocker

[mushymanrob]

interesting developments on the noaa's overnight, suggesting a pressure rise across the uk and possibly suggesting the beginings of the expected long hot settled spell?.. of course more runs are needed but theres room for optimism if you want hot weather.... theres at least a lot of mainly dry, sunny, warm weather on offer with the possibility of some real heat too. potentially great charts IF they firm up with subsequent runs.

 

[knocker]

11 minutes ago, mushymanrob said:

interesting developments on the noaa's overnight, suggesting a pressure rise across the uk and possibly suggesting the beginings of the expected long hot settled spell?.. of course more runs are needed but theres room for optimism if you want hot weather.... theres at least a lot of mainly dry, sunny, warm weather on offer with the possibility of some real heat too. potentially great charts IF they firm up with subsequent runs.

 

I looked at these last night and I must admit I cannot see any suggestion of pressure rises over the UK in the 8-14. To me it appears to show a very slack westerly flow, particularly in the east, with a weak trough over the UK and further south. This would appear to indicate a slack pressure regime with possible  a shallow low to the south. No particular anomalous areas apart from the Canadian lobe with the positive anomaly mid Atlantic very weak. Of course the later NOAA covers quite a time span and developments towards the end of the period may not show up, It will be interesting to see what the EPS comes up with because the GEFs was not that encouraging.and in fact is not dissimilar to the NOAA

Edited July 10, 2017 by knocker

[knocker]

This morning's EPS is looking much more encouraging. Still retaining the Canadian lobe but with a much weaker trough and some significant positive anomalies and ridging in mid Atlantic edging east during the period. Thus more settled and warmer for most by the end of the period.

EDIT

By warmer I don't mean heat wave but maybe slightly above average.

Edited July 10, 2017 by knocker

[draztik]

14 minutes ago, Frosty. said:

Agreed, plenty to be positive about, despite what a few are saying.

 

19 hours ago, Frosty. said:

It's noticeable how the much trumpeted potential change to warmer more settled weather which was originally anticipated mid July is slipping back and back, now it may arrive at the tail end of July and last into August but a flick through the GEFS 6z mean doesn't show any sign of it, just the usual waxing and waning of the azores high / ridge against low pressure systems to the nw / n which means the south looks better than the north but in a generally mobile atlantic pattern.

 

 

[Frosty.]

Just now, draztik said:

 

 

That was yesterday's 6z I was referring to, didn't you notice what I said about the 12z..probably not!

[draztik]

Just now, Frosty. said:

That was yesterday's 6z I was referring to, didn't you notice what I said about the 12z..probably not!

Sorry, I did not. Your opinions change so quickly, it' hard to keep up.

[Frosty.]

Just now, draztik said:

Sorry, I did not. Your opinions change so quickly, it' hard to keep up.

It's called going with the flow, calling each run as I see it..you should try it!

[mb018538]

Those anomaly charts are from yesterday??

[mushymanrob]

1 hour ago, knocker said:

I looked at these last night and I must admit I cannot see any suggestion of pressure rises over the UK in the 8-14. To me it appears to show a very slack westerly flow, particularly in the east, with a weak trough over the UK and further south. This would appear to indicate a slack pressure regime with possible  a shallow low to the south. No particular anomalous areas apart from the Canadian lobe with the positive anomaly mid Atlantic very weak. Of course the later NOAA covers quite a time span and developments towards the end of the period may not show up, It will be interesting to see what the EPS comes up with because the GEFs was not that encouraging.and in fact is not dissimilar to the NOAA

the 8-14 day charts arent as accurate as the 6-10 and often fail to pick up on changes whilst the 6-10 has much higher success rate , the current 6-10 has a slacker and more westerly upper flow, compared to a previous chart (first chart). the current 6-10 day  indicates to me higher pressure/ ridging over the southern uk? no heatwave - yet, but the evolution is heading in the right direction and this should produce a lot of very pleasant mainly dry summery weather .

 

[Man With Beard]

I'll ignore the unnecessary slanging match around me and focus on the models.

To me, the idea of things getting better is still looking good. One key indicator to me is where the yellow line runs on the 500mb chart - a good (though not infallible) indicator of where generally more settled and less settled weather is to be found - you'll generally find mother lows and colder air to the north of this line, and secondary lows running off the Atlantic often travel along this line. Note on the ECM mean chart how this yellow line moves further north in 10 days time (20th July, so closer to mid-July than the end of July).

  

Haven't got this morning's extended ECM yet, but looking at last night's, one can see heights rise even further in the days that follow, all the way from Scotland across Scandinavia. The GEFS at the same timeframe as the later ECM chart (D14, 24th July) is no different, and maybe even slightly better.

   

Another indicator important for me is getting rid of troughing to our NE. Troughs to the NE encourage a northerly element into the flow, which keep injecting cooler air and preventing a sustained warm-up. Again, good news. Track all the means charts and one can see the upper trough gradually moving back from the NE, eventually by the 20th-24th July period being found either comfortably to our NW or just flat to the N. On the last GEFS chart, one would expect lows to still affect the UK from time to time (especially the NW areas), but they would always remain on the western side, meaning lows would be warm and thundery, and potentially just interruptions within a generally settled picture. On the flatter ECM chart (middle one), it is possible the UK could avoid lows altogether for a period.

Looking at individual ensembles, you can see the movement. Looking at my two indicators again, the GEFS at D10 has 10/22 charts with the yellow line running through Scotland, and 12/22 with the yellow line north of Scotland. By D14, 7 still affect Scotland with 15 to the north or west (most are well to the north). So the trend is definitely to lift the yellow line further and further away. Concerning troughing to the NE, even better. At D10, 10/22 chat have a trough close to the NE. By D14, only 3/22 have troughing in that area.

So confidence must be reasonable that even northern areas will get a taste of summer before too long. Further south, it looks highly likely that warmer spells will continue.

Caveats of course.

1. Predicting drier, warmer weather is not the same as predicting a heatwave. To predict 30C plus more than 10 days out is a bit crazy. We've got a bit used to these turbo-charged hot spells in recent years, but they aren't the norm - 25C and sunny spells used to be considered good! So best not to interpret the Met Office updates, or my post, as a "heatwave" prediction. I think it's possible, but equally a decent spell of westerly based "warm" weather could be the result.

2. As we all know, even the small cluster in the ensembles can be right. There's never a guarantee on any long-range forecast.

But the good signs are still here, and they've been pretty consistent for days. I remain optimistic.

[knocker]

21 minutes ago, mushymanrob said:

the 8-14 day charts arent as accurate as the 6-10 and often fail to pick up on changes whilst the 6-10 has much higher success rate , the current 6-10 has a slacker and more westerly upper flow, compared to a previous chart (first chart). the current 6-10 day  indicates to me higher pressure/ ridging over the southern uk? no heatwave - yet, but the evolution is heading in the right direction and this should produce a lot of very pleasant mainly dry summery weather .

 

Yes the earlier chart shows some ridging in mid Atlantic thus the upper flow slightly north of west and more unsettled than the second chart which has backed the flow a tad to a flat westerly There are very slight positive anomalies from the Azores to the southwest and basically an indication of what this morning's det output suggests which is the N/S split with the south benefiting from the Azores ridging NE.I wasn't aware you weren't taking the 8-14 into account as I thought we were looking long term. Anyway we can just agree to differ mushy

And as I mentioned earlier the ext EPS is looking much better this morning.

Edited July 10, 2017 by knocker

[knocker]

This mornings EPS anomalies in the 6-10 range

[mushymanrob]

26 minutes ago, knocker said:

Yes the earlier chart shows some ridging in mid Atlantic thus the upper flow slightly north of west and more unsettled than the second chart which has backed the flow a tad to a flat westerly There are very slight positive anomalies from the Azores to the southwest and basically an indication of what this morning's det output suggests which is the N/S split with the south benefiting from the Azores ridging NE.I wasn't aware you weren't taking the 8-14 into account as I thought we were looking long term. Anyway we can just agree to differ mushy

And as I mentioned earlier the ext EPS is looking much better this morning.

well i did post the 8-14 chart too, which indeed isnt as positive for height rises as the 6-10, and i am guilty of some hopecasting because i do believe, and have done for some time, that we will get a decent hot spell this summer. (based on historic patterns)  ive already had 9 days of 25c+ which in most recent summers has not been reached. in fact only 2013 had as many for me - and as ive said, historically early hot spells is more likely to lead to a decent lengthy hot spell in the second half of summer. of course this isnt a hard fast rule - but just a case of % . it woldnt surprise me if we end up with the 'best' summer since 1995.... in england and wales anyway, i know the north is seeing very little of our summery regime.

[Frosty.]

An accurate summary for this week, however, today is still very warm across the south-east at 26/27c 80f and feeling humid too with a few heavy thundery showers but then the SE joins the rest of the uk with a cooler changeable spell and midweek could be particularly wet down south..The south-east is having a gorgeous summer though so far and I'm sure there are more similar spells to come, hopefully including the north too!

[Man With Beard]

Another run, same general story - heights lifting through NW Europe between D8 and D12

   

ECM 00Z extended now freely available, same story

      

Increase in mean upper air temps of between 2C and 6C for the north over the course of a week

      

 

[knocker]

19 minutes ago, Man With Beard said:

Another run, same general story - heights lifting through NW Europe between D8 and D12

   

ECM 00Z extended now freely available, same story

      

Increase in mean upper air temps of between 2C and 6C for the north over the course of a week

      

 

But the significance of the ext EPS, IMO of course, is the strong positive anomalies in the Atlantic from the Azores and the weakening trough adjacent to the UK, not the ridging in eastern Europe.

Edited July 10, 2017 by knocker

[Man With Beard]

2 minutes ago, knocker said:

But the significance of the ext EPS is the strong positive anomalies in the Atlantic from the Azores and the weakening trough adjacent to the UK, not the ridging in eastern Europe.

That is true (though there are some minor improvements in Scandinavia), and less support for the type of Euro High that could bring an extreme heatwave. But I think the two things you mention are enough to bring improvements to the UK on their own.

[Frosty.]

2 hours ago, draztik said:

Your opinions change so quickly, it' hard to keep up.

It's interesting you should say that, but the models change, sometimes quickly from run to run so I adapt accordingly!

Edited July 10, 2017 by Frosty.

[DR(S)NO]

3 minutes ago, Frosty. said:

Longer term signals are still looking good for a return of warmer more settled weather, it's just the northwest corner which sticks out like a sore thumb with the cooler atlantic conditions but for many, hang in there as another summery spell could be on the way beyond the generally changeable and cooler period we are now entering.

Oh dear Frosty...

I think I may have to change my name to Dr (G)Loom the weather has been so poor here...

I wish there was an opportunity for warmer and settled weather to ' return ' here.... It's been anything but

Im afraid, for me, this Summer so far has been very much a jam tomorrow scenario!

[Frosty.]

3 minutes ago, DR(S)NO said:

Oh dear Frosty...

I think I may have to change my name to Dr (G)Loom the weather has been so poor here...

I wish there was an opportunity for warmer and settled weather to ' return ' here.... It's been anything but

Im afraid, for me, this Summer so far has been very much a jam tomorrow scenario!

Hey I'm trying my best for you, just going by the latest update and the charts posted this morning by man with beard and mushy rob..and yesterday's always excellent post from Tamara..don't give up hope.

[Fourty Point Three Degrees]

11 hours ago, Ice Man 85 said:

1) Its 15 days away

2) Its the GFS

3) Its the GFS 18z

4) The temps on that chart are 5-10c below what 40c is saying. Even the GFS doesn't undercook that much.

5) The ensembles don't agree with it.

1) Congratulations would you like a medal for making that observation

2) and 3) Its GFS and GFS is a model whether 6, 12, 18z and this is model discussion

4) The chart which was posted could deliver the temps in the range I suggested

5) Still doesn't mean it wont come off

[Frosty.]

Longer term, this looks better from the GEFS 6z mean, the alignment more sw / ne is what most of us want to see for further warm / hot spells this summer..which would hopefully include scotland next time!

[Frosty.]

As expected with a mean like that aligned sw / ne with heights from the azores to scandinavia there are some peachy GEFS 6z perturbations..yes it's longer term but it fits with what Exeter keep saying.