Model Output Discussion 13/11/13 >

[MPG]

 Stope teasing us Ian  Whats the story into December !?!?!?

It means December is too far away to even discuss in model terms!

[A.J]

Steve...without question you thoughts are well documented, however can I just make this one simple point to you. 

 

Not everyone is going to read every post you make and fully understand them, especially the rather technical ones.  Therefore it can be confusing to see you lambasting the GFS one moment, then as with this morning 'at least appearing' to support what it shows a short time later....including stuff like 'smelling the coffee' won't always resonate with everyone.  I guess this is why the mods ask for one liners to be kept out of the MDT.

Shed, this is the Model Output Discussion, where all related postings are encouraged providing of course that they remain on topic....In this instance, Steve Murr has commented on why he believes the GFS model output is not as accurate as other model outputs. Whether he is right or wrong is actually irrelevent. Your post has inferred (and I stand corrected if wrong) that if he critiques the accurary of the GFS then he should by default not be allowed then to comment on what that particular model shows?....If so, then that is rather an unfair point of view IMHO......

 

I think a line needs to be drawn under this, and as mentioned earlier on, discussion and debate is what this forum is all about, but it gets to the stage when the same posts/arguments get regurgitated time after time detracting from the thread. Best advice I can give for everyone is not to be afraid to air one's viewpoint, but there comes a time when it's best to agree to disagree if neccessary and move on..

 

For comparing model output performance I'd recommend posting in these two threads...  http://forum.netweather.tv/topic/72326-model-resolution/  and http://forum.netweather.tv/topic/72353-how-did-the-models-perform/ ....leaving this thread purely for the purpose of discussing what the model outputs are actually showing...

 

cheers

[SomeLikeItHot]

I guess that average will feel relatively mild, the point I'm trying to make is the met office in nov 2010 had an emphatically high confidence of repeated cold blasts from the north and east but this time there is nothing remotely like that indicated, I'm just keeping it real rather than giving false hope. :-)

 

No where in the further outlook do they say it will return to average. Nor do they even say near average. They said "nearer to average" ie warmer than the previous period when they forecast wintry showers in the SE and Cold in the NW (ie a cold period).

 

Also not to forget that "average" in December is colder than average in November.

Edited November 18, 2013 by SomeLikeItHot

[Snowy L]

To clarify: MOGREPS merely veers the E/SE faster than EC. There's no suggestion of 'mild', merely return to average. Moreover, UKMO analysis is focused on next 10d (to 15 at a push). The story into December is another matter.

 

When is the switch to milder weather going to happen according to the Met Office? The way it's been said here makes it sound worrying but if it's around week 2 of December then it would make a lot more sense. With the vortex expected to split, zonal should surely be out of the question for the next 2-3 weeks, especially as the position of the split is a favorable one for our location.

[shedhead]

EC ensembles, 36 out of 51 go for pressure rises to the NW by next weekend.

How far NW though? High pressure just to the NW of Scotland/N Ireland can result in relatively mild, cloudy conditions for most if not all of the UK. 

[SnowBallz]

They may be already be using the new data in there current model, and that could be why there outlook is a lot different to the other models!!

 

Hi Timbo,

 

To be honest, it doesn't really work like that.  The c-40 upgrade is a major change to the operational programme that performs various calculations against data, and the design of it has been taking place in the developmental environment over in Reading since earlier this year.  The current ECM ENS Op programme is only able to perform calculations against data which it has been written to accept.  The point here is: yes there is a greater depth of data available from satellites (mainly) but the current programme just doesn't even recognise it.

 

Major upgrades like this lid increase are worked-up in Dev, because it's not only the level increase that needs to be modeled into the algorithm, but also you need to fine-tweak ALL of the interdependent tolerance values.  That takes time; runs and runs, using test data and verifying that the expected consequences are within boundaries.  I think I read somewhere that in excess of 10,000 runs have been run against c-40 in Dev - which is an almost continuous cycling.

 

I did drop in many months ago that the ECM guys were working on a field that specifically focused on SSW.  This was being done in Dev, and I do know that it was parsed into the programme to utilise the lid-level data.  Going forward, this upgrade will - amongst other things - allow NWP to begin to understand and calculate the variables and level interactions between the strat and trop.  That's a very exciting area of understanding; embryonic at the moment, but significant potential wrt LRF.

[fergieweather]

It means December is too far away to even discuss in model terms!

Correct. They're rightly more focused on this week rather than speculating on something at T+240 outbound!

[Frosty.]

No where in the further outlook do they say it will return to average. Nor do they even say near average. They said "nearer to average" ie warmer than the previous period when they forecast wintry showers in the SE and Cold in the NW (ie a cold period).

 

Also not to forget that "average" in December is colder than average in November.

That's splitting hairs, the met office are indicating a return to average zonal type weather further into dec, sooner than that across the north of the uk. The Ecm with it's freezer further outlook is leading people up the garden path but I have smelled the coffee and supporting the met office line. :-)

[johnholmes]

can we PLEASE stop arguing having different opinions of the Met O outlook; there is a thread to discuss thie interpretation of the models. 

please?

[Barry12]

That's splitting hairs, the met office are indicating a return to average zonal type weather further into dec, sooner than that across the north of the uk. The Ecm with it's freezer further outlook is leading people up the garden path but I have smelled the coffee and supporting the met office line. :-)

 

Frosty, you seem to have turned from an extremely optimistic person to an extremely pessimistic person overnight. The Met Office, as Fergie has said are not confident in something what may or may not happen in 10+ days time. I see no reason at all to think we will return to zonal weather looking at the various model outputs.

Edited November 18, 2013 by Barry95

[Mucka]

What has right to do with it?

Correct. They're rightly more focused on this week rather than speculating on something at T+240 outbound!

Edited November 18, 2013 by Mucka

[MPG]

How far NW though? High pressure just to the NW of Scotland/N Ireland can result in relatively mild, cloudy conditions for most if not all of the UK. 

Have a look at the models for yourself Shedhead and posts some charts to show your point. I would but on my phone. Really bored of you undermining everyone on this forum, you know exactly what high pressure to NW means - towards Greenland. That is the current theme being debating at the momment, especially the differences between the GFS and ECM where the high goes.

Edited November 18, 2013 by MPG

[tight isobar]

Cross model, are by far in atm in logger heads more so with the finer details mid/long term I think time on the develops with regards, via any zonal or extensions regard below average and precips type etc.Thinking point towards a more aligned agreement soon...I'm not saying where I personaly feel we will end up.! For the fact of leaving one self open to ridicule....

[MPG]

How far NW though? High pressure just to the NW of Scotland/N Ireland can result in relatively mild, cloudy conditions for most if not all of the UK. 

? Towards Greenland - the current theme being debating on the recent output. GFS compared to EC.

[summer blizzard]

To clarify: MOGREPS merely veers the E/SE faster than EC. There's no suggestion of 'mild', merely return to average. Moreover, UKMO analysis is focused on next 10d (to 15 at a push). The story into December is another matter.

 

Fergie, good to have this information.

 

Regarding the return to average but the veer from the SE, how effective is the MOGREPS in being able to forecast inversions given the likely-hood of them under a continued high pressure scenario,

[Frosty.]

Looking at the Ecm 00z ensemble mean we see a conflict by the weekend between what it shows and the experts view which is for the north to become fine with overnight fog but the mean shows another freshening of the N'ly airflow during next weekend with wintry showers pushing down the north sea coastal areas from the northern isles down to kent with the anticyclone centred further west...........and, there is no sign of the high sinking south on the ens mean as the experts described, so, the ecm mean is already out of sync by the weekend onwards with the ecm showing a very prolonged spell of rather cold benign weather and no sign of any atlantic breakdown looking remotely possible.

Edited November 18, 2013 by Frosty.

[EML Network]

It's always the same at Winter, the ECM and the JMA will join forces showing some decent cold and potential snow at +192 and beyond, the UKMO will often look like it's headed that way too, and the GFS will more often than not say ''No way Pedro''

 

Then after a few days worth of runs the models will all move toward one another and end up closer to the UKMO output.

 

It's very rare that the GFS is all out on it's own showing cold and snow potential with the other models showing a milder set up ...I wonder why it's always the ECM and JMA that seem to favour showing a route to cod and snow only to thyen back down ??

 

I lost count the number of times I saw this last Winter, especially in December !

[Snowy L]

It's always the same at Winter, the ECM and the JMA will join forces showing some decent cold and potential snow at +192 and beyond, the UKMO will often look like it's headed that way too, and the GFS will more often than not say ''No way Pedro''

 

Then after a few days worth of runs the models will all move toward one another and end up closer to the UKMO output.

 

It's very rare that the GFS is all out on it's own showing cold and snow potential with the other models showing a milder set up ...I wonder why it's always the ECM and JMA that seem to favour showing a route to cod and snow only to thyen back down ??

 

I lost count the number of times I saw this last Winter, especially in December !

 

I didn't lose count, in fact it only happened once in December. ECM got the January cold spell after the GFS repeatedly telling us that it would never happen, only to back down 2, yes 2 days before the cold spell started. GFS will go for mild close to 100% of the time, so it's bound to get it right at a few times. ECM is much more adaptable and while it is prone to overplaying cold scenarios it will smell the coffee a lot sooner than the GFS.

[fergieweather]

Frosty, you seem to have turned from an extremely optimistic person to an extremely pessimistic person overnight. The Met Office, as Fergie has said are not confident in something what may or may not happen in 10+ days time. I see no reason at all to think we will return to zonal weather looking at the various model outputs.

Yup, to be clear (and allow more meaningful model discussion to continue!), the UKMO view is for good agreement on high to NW to then migrate E to Scandinavia, in turn allowing an initially NE flow to veer more SE. Perhaps something more developmental thereafter, but they emphasise timing uncertainty on return to temps "nearer average" (which by definition are declining anyway, so not 'mild'). There's no current suggestion of some full-blown swing to zonality (as many others on the forum have already indicated). But given the vagaries in NWP outcome even into this week, it's hardly surprising that Ops Centre barely mention latest 00z EC DET. Either way - and again as others here have stressed - I see nothing for any of the cold aficionados to wig-out about, albeit more likely a fog/frost outcome at least into the reliable(ish) timeframe. Whatever will happen will happen...! Edited November 18, 2013 by fergieweather

[carinthian]

Frosty, you seem to have turned from an extremely optimistic person to an extremely pessimistic person overnight. The Met Office, as Fergie has said are not confident in something what may or may not happen in 10+ days time. I see no reason at all to think we will return to zonal weather looking at the various model outputs.

Hi,

 Thats born out by our team in Vienna. They think changes will be slow during the first part of next week with perhaps a slight shift of the high pressure centre over Scotland to the SW. Low confidence thereafter regarding a mild Atlantic zonal erosion into the Northwest. This Thursday , some snow fall likely over the Welsh Mountains  (1-5 cm )and on Friday  to affect some of the higher ground of Southern Central England. High centred over Scotland this weekend and Low pressure circulation over the Alps with a keen Nely over SE Britain  for a time moving into France early next week.

c 

[phil nw.]

With the 12z runs coming soon i will lock this shortly and open a new thread so hold off any posts for 5.

Thanks all.

[phil nw.]

Right this one now closing-new thread here folks.

http://forum.netweather.tv/topic/78508-model-output-discussion-18th-nov2013-12z-onwards/