Model Output Discussion 17th Dec.2013-12z onwards.

[Frosty.]

Happy New Year GANG

 

And a happy new year from the Ecm 00z op run, an increasingly cold and blocked outlook from T+216 hours onwards with frosts becoming widespread and sharp, in the meantime we await to see if the gfs zonal train will hit the buffers by 6z.

[SMU]

Morning-

 

Lets hope the ECM is not a red herring-

 

Consistancy abound in the last 3 days with the inland runner-

http://www.meteociel.fr/modeles/ecmwf/runs/2014010100/ECH1-120.GIF?01-12

 

Remember weather is all about timing- our Scandi high hinges on the phasing of that low over the central conus @ 120-

 

most other models are east of this track & therefor the signal of ridging is muted- it has to be said the ECM ensembles have been quite bullish about the track but not quite as west as the op-

 

I cant remember who I was telling the other day about 35 degrees of angle-

 

http://www.meteociel.fr/modeles/ecmwf/runs/2014010100/ECH1-168.GIF?01-12

 

if anyone wants to measure the angle of ridging over greenland its about as flat as we can get to support a scandi high- anymore eastward vector & the UK will be submerged on the SW winds..

 

I would say the above chart is about 40 degrees NE....

 

S

[Biggin]

Morning-

 

Lets hope the ECM is not a red herring-

 

Consistancy abound in the last 3 days with the inland runner-

http://www.meteociel.fr/modeles/ecmwf/runs/2014010100/ECH1-120.GIF?01-12

 

Remember weather is all about timing- our Scandi high hinges on the phasing of that low over the central conus @ 120-

 

most other models are east of this track & therefor the signal of ridging is muted- it has to be said the ECM ensembles have been quite bullish about the track but not quite as west as the op-

 

I cant remember who I was telling the other day about 35 degrees of angle-

 

http://www.meteociel.fr/modeles/ecmwf/runs/2014010100/ECH1-168.GIF?01-12

 

if anyone wants to measure the angle of ridging over greenland its about as flat as we can get to support a scandi high- anymore eastward vector & the UK will be submerged on the SW winds..

 

I would say the above chart is about 40 degrees NE....

 

S

Steve, what is a conus ??

[IDO]

Steve, what is a conus ??

CONUSContiguous United StatesThe contiguous United States refers to the 48 adjoining U.S. states on the continent of North America that are south of Canada and north of Mexico, plus the District of Columbia.Wikipedia Edited January 1, 2014 by i'm dreaming of...

[bluearmy]

Biggin, the conus is n america and more specifically, the usa

EDIt: can we try google in future before asking ?? It leads to double replies like this and i know from experience that on a day like this, people will come on late and then trawl through pages of posts. Ones like this and the duplicate one above will annoy!

Edited January 1, 2014 by bluearmy

[Frosty.]

GFS 00z op run shows a higher risk of sleet / wet snow for parts of the west and north later on friday and into saturday, ireland in particular, not just on hills, also across cumbria and the north pennines and then scotland, especially higher ground could have a spell of snow for a time on sunday before it turns back to rain. The gfs shows no end to the very unsettled and stormy pattern with further potential disruption due to flooding and storm damage if this run verified, cyclogenesis remains rampant but we still get occasional cold and showery incursions with wintry showers and night frosts between the bouts of wind and rain.

Edited January 1, 2014 by Frosty.

[Frosty.]

Steve, what is a conus ??

continental united states

[tinybill]

http://www.meteociel.fr/modeles/gfse_cartes.php?mode=2&ech=204

 

 

morning  all happy new year pity the weather has not changed  here in the u.k. needs dry weather  looking deep into f1  its still more of the same  rain,rain, floods

[weather eater]

A mixed bag this morning the ECM has promise but I now have little faith in its modelling of these types of synoptics as we have seen some major climb downs the last year or so by the ECM with this type of modelling. The GFS is really as you were, some changes from recent offerings in its low res but it’s still pretty zonal throughout.

Edited January 1, 2014 by weather eater

[Gibby]

Good morning everyone and a very Happy New Year to you all. Here is my 1st report on the midnight outputs from NWP for today Wednesday January 1st 2014.

 

All models remain very unified in stating that the current unsettled spell will continue for at least the next 7 days with Low pressure areas continuing to crash across the Atlantic up to the NW of Britain. This maintains the feed of strong to gale and locally severe gale force SW winds at times along with areas of rain and showers repeatedly crossing quickly NE or East in the flow. The rain will be persistent and troublesome at times giving rise to surface flooding issues almost anywhere but more likely to the usual prone locations. In the showery interludes the usual winter cocktail of hail, thunder, sleet and snow is just about possible particularly near Western and Southern coasts with only very short windows of drier weather in between.

 

GFS then takes us through the middle and end of next week with some moderation in the wet and windy regime for a time as isobars open out with somewhat colder air in tow for a time. However, on this morning's operational run it isn't long before renewed Atlantic gales and heavy rain sweeps back in off a volatile Atlantic for the remainder of the period to maintain the pattern that we have grown so used to since mid December with little chance of wintry weather.

 

The GFS Ensembles back up this theme very well with a heavy bias towards Westerly winds being maintained and heavy rain at times throughout the period with temperatures never far from average overall.

 

UKMO today shows a deep depression near 950mbs between Scotland and Iceland next Tuesday which means a continuation of strong WSW winds and showers at least and most likely some longer spells of heavy rain in places too with temperatures close to the January average.

 

GEM shows this feature filling in situ as we move through the middle and end of next week with the rain and showers dying out slowly before High pressure building to the SE sets up a milder SW flow with rain for the North and West to end next week.

 

NAVGEM also shows this feature filling up to the NW over the middle of next week but insufficiently to change the weather pattern of rain or showers within the confines of the run this morning.

 

ECM is looking very isolated in it's prediction of a pattern change later next week and carries on from where it left off last night developing it further into a Scandinavian High pressure by the end of the week coupled with a tongue of cold air wafting gently West towards Southern Britain in slack conditions. There would continue to be a risk of rain from this slack pressure zone across the South perhaps turning wintry over the hills.

 

The ECM Ensembles Mean chart for 10 days does not support the operational ending up looking more like GEM in 10 days time with High pressure biased towards being to the SE of the UK and the rampant Atlantic set to pounce once more. However, I realise this is just half of the picture and there will no doubt be some support for the operational in among the gloom of the other members of it's set.

 

http://www.wetterzentrale.de/pics/Reem2401.gif

 

The GFS Jet Stream forecast suggests the flow maintains it's current trajectory for some while yet with only minor tweaks and adjustments North and South over the UK in the forecast period.

 

In Summary today there is a split in the output theory on developments following the filling of a large depression North of the UK towards the middle of next week. While much output doesn't stretch out far enough to evolve it on it looks unlikely that GEM or NAVGEM would follow any other route than that of GFS which maintains a strong Atlantic flow with deep depressions continuing to rattle over the Atlantic with all the wind and rain to which we have become accustomed maintained well into mid January. However, ECM has other ideas with a block forming over Scandinavia and with Low pressure West of Iberia and over Eastern Europe the block could be supported at this Northern latitude without collapse. The Day 10 chart is quite a clever chart as it leaves you wanting it to move on a few more days as there is certainly a chance of something better for cold fans to grasp hold of today. The main problem however, is the Ensemble mean chart for day 10 puts a bias towards High pressure to the SE of Britain whilst drier would hardly lead into something notably cold. More runs needed and greater cross model support too.

[Weather-history]

Looking at the GFS 0z pressure ensembles for Manchester, there is a hint of increase in pressure around the 9th in the ensembles , which says to me a less volatile set-up maybe later. Less vigorous lows perhaps even more high pressure.

[IDO]

Good support from the ECM Control for the op synoptics, from the Dutch ensembles:

 

 

 

Although the ECM mean chart doesn't really support the op, with respect to surface conditions:

 

 

The upper heights are not too far from support and I suspect there is a split in the ensembles. The anomaly chart highlights this:

 

 ...no strong anomalies in the important areas; they have cancelled each other out.

 

Still have to get GFS on board as their mean has a much weaker signal:  

 

Is it another ECM over amping, probably, but on this occasion there appears to be a cluster towards the op's outcome, so tentative hopes?

Edited January 1, 2014 by i'm dreaming of...

[shedhead]

Well at least we have some major disagreement in the overall evolution post T+216, with ECM developing a Scandi high that extends across the UK... 

 

...whilst GFS keeps the Atlantic train firmly on the tracks.

 

Clearly they can't both be right, perhaps neither of them will be come late next week, but whilst my heart says ECM my head says GFS....for now at least.

Edited January 1, 2014 by shedhead

[That ECM]

http://www.bbc.co.uk/news/blogs-the-papers-25565210

When did you start working for the papers Steve?

[bluearmy]

Good support from the ECM Control for the op synoptics, from the Dutch ensembles:

 

eps_pluim_tt_06260 (2).png  eps_pluim_dd_06260 (2).png

 

Although the ECM mean chart doesn't really support the op, with respect to surface conditions:

 

EDH1-240 (4).png

 

The upper heights are not too far from support and I suspect there is a split in the ensembles. The anomaly chart highlights this:

 

EDH101-240.gif  ...no strong anomalies in the important areas; they have cancelled each other out.

 

Still have to get GFS on board as their mean has a much weaker signal:  gensnh-21-1-240 (2).png

 

Is it another ECM over amping, probably, but on this occasion there appears to be a cluster towards the op's outcome, so tentative hopes?

 

not wanting to over react to one extended ecm ens suite but safe to say that the op is not something that could be considered an outlier and i wouldnt expect the atlantic to be rushing back in as it is now and will be for the next week or so.  

[Cloud 10]

Yes,lots of uncertainty in the 10 days+ outlook with some large differences between

the ECM and NAEFS....

 

ECM..  NAEFS..

 

 

...which was highlighted in the CPC discussions last night.

 

Climate Prediction Center - 6-10 and 8-14 Day Prognostic Discussions

 

 

Happy new year . 

[Ice Day]

Although it's at 240 so has to be taken with a large pinch of salt, it is nevertheless good to see much colder uppers finally appear to our east.

 

[Summer Sun]

Next Thursday remains the day when we could see a change to something less stormy developing the ensemble continues to support a quieter period developing

 

 

The 850's look to be around -0 to -3 so possibly cold enough for snow on high ground in Scotland

 

Edited January 1, 2014 by Summer Sun

[Frosty.]

The GEFS 00z mean is painting an increasingly rather cold and unsettled outlook, especially further north (scotland in particular) with a chilly westerly flow of polar origins, so an increasing risk of wintry ppn towards mid month and some frosty nights, gradually becoming less stormy but not settling down for any length of time.

Edited January 1, 2014 by Frosty.

[Ice Day]

Quite big differences on the GFS at 144 on the 6z comparing to the 0z.  Better heights into scandi, not sure what the repercussions later will be though?

 

Edited January 1, 2014 by Ice Day

[Captain Shortwave]

GFS 06z is completely different to the 00z. But also vastly different to the ECM, UKMO and GEM which all in turn differ from each other at 5/6 days out.

Need a lie down 

[Purga]

Morning folks - not too many sore heads I hope!

 

Tentative signs of a change maybe with some ECM ENS (Reading) continuing to show a cool down after about the 9th Jan

This with the De Bilt ENS indicating a possible easterly is not so low a probability. Let's hope so.

 

De Bilt ENS

Edited January 1, 2014 by Purga

[Ice Day]

GFS 06z is completely different to the 00z. But also vastly different to the ECM, UKMO and GEM which all in turn differ from each other at 5/6 days out.

Need a lie down 

 

You're not wrong. One consistent theme though is the chunk of PV still showing as lifting away from Canada! This at 180

 

[Methuselah]

GFS 06z is completely different to the 00z. But also vastly different to the ECM, UKMO and GEM which all in turn differ from each other at 5/6 days out.

Need a lie down 

Indeed, completely different: http://www.youtube.com/watch?v=l6Dd0EaEbqg

[swilliam]

GFS 06z is completely different to the 00z. But also vastly different to the ECM, UKMO and GEM which all in turn differ from each other at 5/6 days out.

Need a lie down 

Yes it seems GFS is having nothing to do with the inland track of the US low and the consequent sharp mid atlantic ridge which leads to the weak Scandi ridge on the ECM. However it does seem to be favouring more robust buildng of heights to the NE in general.

 

However it seems unlikley that this pattern could give us anything very interesting from a cold perspective in the medium term as it allows the reforming vortex to take up residence close to NW UK. Maybe some cold zonality due to its close proximity which I think was what the Meto were alluding to in the 15-30d upate yesterday regarding more wintry conditions - especially for the North..

I think I know which option I would prefer but the odds seem stacked against this. Were it to happen though (and it obviously possible) there would some very incorrect forecasts knocking about at present.