Model output discussion pm 13/01/2016

[IDO]

15 minutes ago, Kentish Snowman said:

That post is completely misleading!

UKMO has been leading the way up until the last day or two with the other models, particularly GFS being dire and playing catch up!

Also, how can a chart 120 hours all of a sudden be correct when the output is wildly different from yesterday and at odds with the METO forecast?

Just a completely bizarre post if you ask me!

Sorry just my reading of the charts and the reason that the GFS has never really been keen on longevity though the GFS op has been progressive (as usual), but the GEFS mean has been closer to Wednesday for the breakdown. That ridging of the Azores was always going to kill any further undercut and assuming it is correct then the UKMO op was the last to spot it. That being a crucial driver to sustain cold I thought it was a big miss, but as you say lets wait till the day to verify.

[Guest]

4 minutes ago, IDO said:

Sorry just my reading of the charts and the reason that the GFS has never really been keen on longevity though the GFS op has been progressive (as usual), but the GEFS mean has been closer to Wednesday for the breakdown. That ridging of the Azores was always going to kill any further undercut and assuming it is correct then the UKMO op was the last to spot it. That being a crucial driver to sustain cold I thought it was a big miss, but as you say lets wait till the day to verify.

The GFS has been nothing short of appalling modelling this period of weather. 

[Matthew Gill]

People talking about 7 days away. The modules haven't even got tonight's event right 5 hours out. Look how much further East the front has now got. It wasn't supposed to get past Leicester and now it looks like it will end up on the east coast the way it's tracking on the radar

[Snowman.]

10 minutes ago, IDO said:

Sorry just my reading of the charts and the reason that the GFS has never really been keen on longevity though the GFS op has been progressive (as usual), but the GEFS mean has been closer to Wednesday for the breakdown. That ridging of the Azores was always going to kill any further undercut and assuming it is correct then the UKMO op was the last to spot it. That being a crucial driver to sustain cold I thought it was a big miss, but as you say lets wait till the day to verify.

The UKMO was the first model to attempt an undercut.

[Banbury]

To be fair UKMO has come out on top, it sang the same song for days with this. GFS picked every option going and of course at some point the Atlantic would creep back in. GFS has had a go at that outcome everyday at some point.

Well done UKMO

[NorthernRab]

1 minute ago, Banbury said:

To be fair UKMO has come out on top, it sang the same song for days with this. GFS picked every option going and of course at some point the Atlantic would creep back in. GFS has had a go at that outcome everyday at some point.

Well done UKMO

How can we congratulate the UKMO for something that hasn't yet happened? Yes, it has performed well over the last week relative to the GFS, but it too has struggled and to suggest that the success over the past week should translate to the success of one particular run seems very presumptuous. 

[Mucka]

So I guess those telling us how consistent and correct UKMO has been will be calling flat zonal now, right?

Here are its last 4 projections for the 21st (12z 12 hours on but we can see the 00z are far more amplified than the 12 output)

 

I guess people believe what they want to believe to a certain extent but no model has handled this well over the last week or so, if they had of been then why have the MetO stressing the uncertainty?

It is still a case of fluctuating and contrasting signals. While UKMO has now moved toward a quicker and decisive breakdown other output has drifted the other way if anything. Yes we are going to get a breakdown but it is likely to slower and messier than UKMO and offer better prospects going forward.

As stated earlier this mornings ECM showed signs of sending more energy SE between 96/120h and I also stated some GFS ensemble members were showing something similar and now with the 12z set we can say there is a proclivity to send more energy SE in this time frame though overall it is fair to say they still want to send energy NE mostly.

Will ECM move toward UKMO or will it build on this mornings output and the signal within GFS ensembles and look more amplified by 144?

Either way a warm up of sorts looks assured but how the building blocks fall will dictate how easy it is to rebuild.

 

Edited January 16, 2016 by Mucka

[nick sussex]

This could well be another UKMO output that bites the dust in the morning, just as last nights was far too progressive.

The issue is the way it handles the troughing to the west of the UK, generally in terms of the overall patterns the outputs are similar but  the GFS/GEM/ARPEGE have this trough set up at T96hrs:

Take the GEM, you can use also the GFS/ARPEGE they're all the same:

Then the UKMO on the right, note the secondary feature and how much more progressive it is. We'll have to leave the deciding vote to the ECM. If that backs the others then I'd view this UKMO output as an outlier and unlikely to verify.

 

 

[Timmytour]

I find an Eastern block to be a little like a teenage adolescent .  When he knows he's strong early doors like December...the Atlantic is no worry. When his muscles develop later like in Jan...he hasnt got much confidence in his own strength...he'll take a couple of hits first before working out he can hit back.

I think the models are looking at an Eastern block that's very well developed.... but can't work out how confident it is .  I think we have block who will maybe take one blow...but then say that's enough and start hitting back. 

[Banbury]

6 minutes ago, NorthernRab said:

How can we congratulate the UKMO for something that hasn't yet happened? Yes, it has performed well over the last week relative to the GFS, but it too has struggled and to suggest that the success over the past week should translate to the success of one particular run seems very presumptuous. 

ok..........up to 1700 it has . It has been consistent in its story...............which is what my post said...................GFS has jumped all over the shop , which is why I said well done UKMO..............I'm not alone with those thoughts I should add

[mb018538]

To be fair it is much harder to judge the UKMO as it only runs out to 144 hours. I would say it has moved towards the GFS slightly, but then the GFS has hardly been stellar itself has it? It merely shows how uncertain this spell of weather has been!

What I would say from my own perspective, is that it has been a bit disappointing in the fact that when it first started to be modelled over a week ago, everything looked so good. Massive heights up north, AO off the charts, ensembles all clustered very cold.....in reality it's been a few chilly (though by no means really cold) days, a little bit of frost and that's it. Days haven't been below 3/4c here, which isn't much off what you'd expect for January anyway. Maybe the mushy mild December has tempered everything.

[Paul_1978]

43 minutes ago, Hammer said:

Per Fergie.

@James1uk we're hopeful of clearer story by end of Sun; models will have assimilated the 2 key dictating factors (in US & SE Europe) for us

In other words - don't take tonight's output at face value. 

@nick sussex Is good at looking at upstream signals so will be a help tonight! 

[nick sussex]

I think theres a danger of viewing past glories as an indicator of future performance. Models all go through good and bad patches.

The UKMO did well last week with its view of keeping high pressure to the north so of course deserves some credit however it dropped the baton last night. This mornings 00hrs then moved back towards the consensus, tonights looks progressive again.

Perhaps its some data issue which is leading to some 12hrs bias. Maybe its found the correct trend. The ECM will be key tonight. If that doesn't back the UKMO then the odds of it verifying against the ECM at T96hrs are slim.

[IDO]

7 minutes ago, nick sussex said:

I think theres a danger of viewing past glories as an indicator of future performance. Models all go through good and bad patches.

The UKMO did well last week with its view of keeping high pressure to the north so of course deserves some credit however it dropped the baton last night. This mornings 00hrs then moved back towards the consensus, tonights looks progressive again.

Perhaps its some data issue which is leading to some 12hrs bias. Maybe its found the correct trend. The ECM will be key tonight. If that doesn't back the UKMO then the odds of it verifying against the ECM at T96hrs are slim.

Yes you could be right with the 12z. The UKMO has verified lower then the GFS in 7 of the last 8 12z runs at D6. It is also rare that the UKMO does not verify better over the previous 31 days, they are the same at the moment:

 

Edited January 16, 2016 by IDO

[nick sussex]

4 minutes ago, IDO said:

Yes you could be right with the 12z. The UKMO has verified lower then the GFS in 7 of the last 8 12z runs at D6. It is also rare that the UKMO does not verify better over the previous 31 days, they are the same at the moment:

 

Interesting thanks for that IDO. I think the UKMO is a very good model but we've seen from all the outputs good and bad runs. Generally the ECM has less bad days overall than the others but isn't immune to a few dodgy runs.

PS Paul 1978, upstream theres not a great deal of difference, the UKMO is a touch less amplified over the ne USA. Overall the models are generally on the same page in terms of the NH pattern. The issue is more the timing of any breakdown rather than if it will or won't, there is a push east of low heights likely and it will be a big task for high pressure to hold on. Theres also not enough amplitude working through to help sharpen up any troughing to the west.

We'll see what the ECM has to say but given the winter so far even if the cold hangs on just to Wednesday/Thursday that's pretty good going given events in December.

 

Edited January 16, 2016 by nick sussex

[doghouse]

Just outside Glasgow city centre, 4/ 5 inches of snow and the most magical day in the park with the kids. Absolutely life affirming stuff. Sod the doomsday charts from 7 or 8 days hence if ye get a dumping get out and enjoy and forget the GEFs ensembles or whatever other statistical morbid fascination is at play with posters who will not or never enjoy what is happening in front of their noses. An emmotional response to such a wonderful thing is what makes having to suffer the relentless statistical negativity worthwhile. 

[Captain Shortwave]

In the end all of the models have performed poorly compared to the usual high standards. It has been a testing time with a lot of interesting background factors which at time have been at odds with each other. A rather poor set of charts on offer in the mid range though this could all swing the other way in the morning.

Longer term.

     

This looks very familiar, we were getting some similar output at the end of December so maybe we could build another powerful ridge towards the pole in a similar location to the turn of the year. Worth noting the GEFs retrograde this into an Atlantic block later.

      

A lot of questions to be asked in the short and long term. I am still unconvinced of a pronounced return to mild and wet conditions.

Edited January 16, 2016 by Captain Shortwave

[NorthernRab]

25 minutes ago, Banbury said:

ok..........up to 1700 it has . It has been consistent in its story...............which is what my post said...................GFS has jumped all over the shop , which is why I said well done UKMO..............I'm not alone with those thoughts I should add

Sorry, I took your post to mean that the latest UKMO run would actually verify because the model has performed well generally as of late. I'd agree it's performed well and apologies for misreading your initial point!

[wishingforsnow]

Hi guys I'm new to this forum but I've been a lurker for a while. This is my first post.

Anyway, going by the Met's latest 30 day outlook, hints from Ian F and recent background signals, I think that if/when there is an Atlantic breakhtrough of the block next week it will not be for long before perhaps an even larger, stronger cold blocking spell arrives at the end of the month in time for February. Also that would tie in with the long range forecasts made at the start of Winter 15/16 that February would likely be the coldest month.

Edited January 16, 2016 by wishingforsnow

[IDO]

1 minute ago, wishingforsnow said:

Hi guys I'm new to this forum but I've been a lurker for a while. This is my first post.

Anyway, going by the Met's latest 30 day outlook, hints from Ian F and recent background signals, I think that if/when there is an Atlantic breakhtrough of the block next week it will not be for long before perhaps an even larger, stronger cold blocking spell arrives at the end of the month in time for February. Also that would tie in with the long range forecasts made at the start of Winter 15/16 that February would likely be the coldest month.

Hi. Yes I think February and March could be interesting, especially if a SSW event occurs. Just need the blocks to sit in the right place when the flood gates open.

[wishingforsnow]

4 minutes ago, IDO said:

Hi. Yes I think February and March could be interesting, especially if a SSW event occurs. Just need the blocks to sit in the right place when the flood gates open.

Indeed. And as I'm sure this has been mentioned by others, previous notable cold spells such as January 2013 also had a temporary Atlantic breakthrough before the cold blocking returned becoming stronger and more prolonged

Edited January 16, 2016 by wishingforsnow

[NorthernRab]

Just now, wishingforsnow said:

Indeed. And as mentioned by others, previous notable cold spells such as January 2013 also had a temporary Atlantic breakthrough before the cold blocking returned becoming stronger and more prolonged

Not to mention 2009 and 2010 which both had 'mild' (or rather, closer to average) interludes. In the case of 2009, occasional milder intervals affected the south while the north remained locked in the freezer. In 2010, everywhere experienced a mild period following the initial cold spell only for a much colder spell to develop. In the case of the current scenario, the block isn't really getting blasted away by any of the models, rather the UK as an island is perhaps going to become subject to incursions of milder air from the west. For how long (if at all maybe?) is the question.

[nick sussex]

The ECM at T96hrs is between the GFS and the UKMO. The issue seems to be how the models either absorb the low at the base of the main trough or take this as a separate feature east in the ECM's case, ne in the UKMO and the others absorb this into the main trough.

 

[bluearmy]

Just checked out the 00z ecmp and it built quite a strong sceuro high later in th run which was at a high enough latitude to keep the milder uppers away in the most part. would be surface chilly .  There are quite a few op runs from several models building heights to our NE in the medium term. the 00z ecmp seems to be predicated on med heights being low - especially an eastern med upper trough.  Note what Ian said earlier re developments in se europe

[Mucka]

Disappointing ECM tonight moving toward UKMO.

Game ,set and match Atlantic or more fun and games tomorrow?

We will have to see how the PV behaves after the Atlantic gets in but NH profile doesn't look too bad,