Model Output Discussion 18z 28/07/13

[Costa Del Fal]

Whilst inter model and inter run detail has and will continue to change, the overall picture looks pretty grim once we get beyond midweek, with much of September now possibly being written off IF things set up as currently indicated.

How on earth can you make that statement? Is the continuous chopping and changing not obvious enough to notice that things are uncertain??? I certainly wouldnt want to forecast beyond Saturday at present!!! Its only the 3rd September. C'mon, you know better than that Shed. Things have changed lots within a day so with 27 days left of the month, how many more times is it going to change!!!

Edited September 3, 2013 by Blizzards

[Summer Sun]

00z ensembles stay the right side of average throughout this lunchtime

 

 

The Aberdeen ensemble is remarkable with uppers well above the seasonal average for the next few weeks with just one blip this weekend

 

Edited September 3, 2013 by Summer Sun

[Frosty.]

Just looking at the GFS 06Z op and the cut-off low just sits there spinning over Ireland for about a week.

 

I've only been model-watching for about a year: is that unusual?

The 6z trough in reality would fill and lose it's identity with pressure rising, the overall pattern looks very slack and slow moving, no sign of any autumn gales and strong zonal conditions which is comforting.

[Summer Sun]

The 6z trough in reality would fill and lose it's identity with pressure rising, the overall pattern looks very slack and slow moving, no sign of any autumn gales and strong zonal conditions which is comforting.

 

Welcome back frosty

 

[Frosty.]

Welcome back frosty

 

Thanks Gavin, it's good to be back

[bluearmy]

tbh, this thread should be almost empty for the past few days as no one should have any confidence in posting anything regarding thursday onwards.  any definitive statements should be avoided as they have a very low chance of being correct. i just hope this split energy theme from the past month or so wears itself out or we will need a lot of mods on here come late november onwards.  the models clearly not capable of dealing with it with any consistency.

[No Balls Like Snow Balls]

How on earth can you make that statement? Is the continuous chopping and changing not obvious enough to notice that things are uncertain??? I certainly wouldnt want to forecast beyond Saturday at present!!! Its only the 3rd September. C'mon, you know better than that Shed. Things have changed lots within a day so with 27 days left of the month, how many more times is it going to change!!!

 

The placing of fronts will continue to change. But the general theme seems to be LP controlling our weather from the end of this week rather than HP?. Nothing on the latest models to suggest HP making a quick come back as the dominante feature again after the end of this week?

Edited September 3, 2013 by No balls like Snow Balls

[Summer Sun]

The placing of fronts will continue to change. But the general theme seems to be LP controlling our weather from the end of this week rather than HP?. Nothing on the latest models to suggest HP will be the dominante feature again after this weekend?

 

It can't be ruled out though look how quickly the models (more so ECM) dropped high pressure for next week after a few days of showing it, the further north you are the more influence it should have

 

 

Later next week onwards who knows what will happen is the honest answer for pressure

 

The one thing what we can agree on is it looks very likely warm uppers look like lasting to at least mid month regardless of the pressure

 

Edited September 3, 2013 by Summer Sun

[No Balls Like Snow Balls]

It can't be ruled out though look how quickly the models (more so ECM) dropped high pressure for next week after a few days of showing it, the further north you are the more influence it should have

 

 

Later next week onwards who knows what will happen is the honest answer for pressure

 

The one thing what we can agree on is it looks very likely warm uppers look like lasting to at least mid month regardless of the pressure

 

 

 

Yep wet but warm seems to be the order of the day. Temp dropping quite considerably though in heavy rain belts.

[Captain Shortwave]

I would add the GEM into the hat here

 

 

 

Plausible solution and apart from a couple of wet blips the weather is controlled by high pressure to our north east. Not every model is gunning for a full unsettled onslaught, The ens still have the Jet over northern Scotland by day 10 as well which again doesn't exactly shout countrywide unsettled weather.

We know from this summer and during the winter that high pressure cells to the east/north east can be a real handful to shift so I wouldn't be surprised if any zonal weather is kept at bay for a good time yet.

[Costa Del Fal]

This requote is purely for the benefit of those with defective/selective eyesight...

 

Whilst inter model and inter run detail has and will continue to change, the overall picture looks pretty grim once we get beyond midweek, with much of September now possibly being written off IF things set up as currently indicated.

No need to be so patronising. Yes you said possibly but to be honest everything is a possibility for our weather. At the start of July I could have said that month would be a write off because some were refusing to accept HP in charge. I could say at the start of October it could be a write off and for November... and for December.... for all months actually. So whats the point of making such statements on the 3rd of the month when its obvious the amount of uncertainty. It could possibly turn out to be an amazing month....

 

Im not having a go here, I just think im making a fair point.

Edited September 3, 2013 by Blizzards

[No Balls Like Snow Balls]

At just 96 hours out this illustrates the uncertainty of placement of the LP.

 

 

 

 

All the big 3 are different.

Edited September 3, 2013 by No balls like Snow Balls

[Frosty.]

The latest met office update shows an unsettled outlook nationwide from this friday onwards and becoming much cooler by friday in the south, well before then further north & west, yesterday the met office said the north would have a more settled spell next week but that's gone now, generally unsettled next week across the board but with some brighter spells, eventually with a typical northwest-southeast split......so it appears like a trough will settle over the top of the uk from friday onwards and persist and be reinforced by further troughs which is pretty similar to what the Gfs 06z op run shows, however, it then looks like the south & east will trend sunnier and warmer whereas the north & west are more generally unsettled and cooler with strong winds at times later in the period which suggests the atlantic eventually becoming more agressive but with a high pressure cell close to the southeast of the BI over the near continent.

[mushymanrob]

Nothing...but I think it's time for a good old Autumn hunt..

 

Let's shift this Summer thread out of the way and move on.

 

eh?... this isnt the summer thread, it wont be the autumn one, its the model discussion thread.

 

Whilst inter model and inter run detail has and will continue to change, the overall picture looks pretty grim once we get beyond midweek, with much of September now possibly being written off IF things set up as currently indicated.

 

write off september? in what way? in terms of heat? rain? cold?

 

september is a transitory month, between the end of summer and the begining of autumn, theres nothing expected and therefore nothing to be written off.

 

i  see the latest runs still do not agree where 'that low' will be situated. gfs 06z suggests ireland, ecm 00z suggests biscay  (heres hoping), its been cited all over the general area between biscay, iberia,  ireland and normandy . with still at least 5 days to go its anyone guess atm.

[Yarmy]

The latest met office update shows an unsettled outlook nationwide from this friday onwards and becoming much cooler by friday in the south, well before then further north & west, yesterday the met office said the north would have a more settled spell next week but that's gone now, generally unsettled next week across the board but with some brighter spells, eventually with a typical northwest-southeast split......so it appears like a trough will settle over the top of the uk from friday onwards and persist and be reinforced by further troughs which is pretty similar to what the Gfs 06z op run shows, however, it then looks like the south & east will trend sunnier and warmer whereas the north & west are more generally unsettled and cooler with strong winds at times later in the period which suggests the atlantic eventually becoming more agressive but with a high pressure cell close to the southeast of the BI over the near continent.

 

Just backing their own model then which parks the low right on top of us. We'll see.

[Captain Shortwave]

Just backing their own model then which parks the low right on top of us. We'll see.

I guess it's all they can do if every model is throwing a different solution at 4 days out. Of course if the UKMO moves the low to the Biscay region this afternoon then the entire forecast is pretty much toast. I can't have a go at them over this.

[Frosty.]

Just backing their own model then which parks the low right on top of us. We'll see.

Yes Yarmy it's not set in stone yet , I am rather hoping for high pressure to the northeast of the BI to have more influence than the latest MO update shows, it does seem as though a cool trough will become trapped either directly over the uk or very close from this weekend onwards followed by a gradual recovery later next week for the south & east as pressure rises across the near continent and the jet becomes aligned sw-ne sending depressions on a collision course with northwest scotland.

[Man With Beard]

Whilst inter model and inter run detail has and will continue to change, the overall picture looks pretty grim once we get beyond midweek, with much of September now possibly being written off IF things set up as currently indicated.

 

I see you've come in for some grief over your comment - a little unfair as I actually agree that some model output does not return HP to our shores in their timeframes - BUT - there has been a pattern for a good two months now for the models to underestimate the strength of the Azores High ridging towards us - personally I don't think we're done with the Azores High just yet, this current cut-off low may just be a temporary fly-in-the-ointment, and indeed I think I've seen signs in the last few runs that the Azores High may re-establish, for example:

 

now this is a chart that we've seen a few times over the last 6 weeks and, though the chart itself is not terribly settled, it generally led to a ridge building a few days later close enough to the UK to keep the real Atlantic nasties out. I can't see any sign of great cyclonic or jet activity to prevent the same thing happening again so considering everything I'm going to back a "fair" scenario for mid-month atm. But I respect your opinion Shedhead

Edited September 3, 2013 by rjbw

[shedhead]

I see you've come in for some grief over your comment - a little unfair as I actually agree that some model output does not return HP to our shores in their timeframes - BUT - there has been a pattern for a good two months now for the models to underestimate the strength of the Azores High ridging towards us - personally I don't think we're done with the Azores High just yet, this current cut-off low may just be a temporary fly-in-the-ointment, and indeed I think I've seen signs in the last few runs that the Azores High may re-establish, for example:

 

now this is a chart that we've seen a few times over the last 6 weeks and, though the chart itself is not terribly settled, it generally led to a ridge building a few days later close enough to the UK to keep the real Atlantic nasties out. I can't see any sign of great cyclonic or jet activity to prevent the same thing happening again so considering everything I'm going to back a "fair" scenario for mid-month atm. But I respect your opinion Shedhead

Thanks rjbw, but be warned.....you are in a minority of one

 

The type of situation currently being depicted by the models does have the potential to become rather stuck, but as I made very clear in my post we're still looking at an IF rather than a WHEN wrt worse case senario, so as ever more runs are needed.

Edited September 3, 2013 by shedhead

[Methuselah]

Just y'all remember just how long it took for proper springtime warmth to arrive this year? IMO, predicting a major pattern-change is where both models and humans struggle the most...Of course, there will be a change; it's just that no-one - neither man nor model - seems to know when or from which direction?

 

Remember the quasi-stationary cold block we endured last spring? Each-and-every model run had a breakdown coming from a different source...Meanwhile, the weather-pattern steadfastly refused to budge...

 

Are we stuck for now? 

[No Balls Like Snow Balls]

I think we can pretty much guarentee Friday is gonna be wet. Within the 72 hour time frame now.

GFS 12Z

 

Edited September 3, 2013 by No balls like Snow Balls

[draztik]

Gfs 12z has LP slap-bang over the UK at t96. It now appears likely that an unsettled wkend is starting to firm up! With a bias towards western parts to see the worst of any rainfall

also, the UKMO and GFS have very similar output to at least t96

Edited September 3, 2013 by draztik

[No Balls Like Snow Balls]

Good agreement with the 12Z GFS and UKMO re placement of low at T96.

 

 

 

Wonder if the 12Z ECM will follow suit?

 

 

 

 

[Summer Sun]

GFS rainfall totals up-to 18:00 on Friday

 

 

Totals up-to 18:00 on Saturday

 

 

And to 18:00 Sunday

 

 

The south east could get away with minimal rainfall this weekend if GFS is correct

[Captain Shortwave]

Well the GEM isn't as awful as the other two

 

 

#strawclutching