Model Output Discussion - Stormy Period Inbound...

[Captain Shortwave]

No worries. Neither of us are right or wrong. Just different opinions that's all.

 

We'll just have to agree to disagree on this one and move on 

Moving on, the control gets close to something very good

Just not enough juice on those weak heights. That wedge to our north/north east to me is still the only real viable option to get something more sustained, as it forces us hopefully onto the cold side of the jet and of course allows very cold air to advance west towards us.

Something like this would do the trick

 

This is heading towards the idea the GEM was playing with for a few runs.

So in my view, losing low heights over Greenland could potentially be a never ending dream. Low heights over Europe is certainly possible so anything to swing odds in our favour would be very useful.

Edited January 10, 2015 by Captain shortwave

[Frosty.]

Well what a stonking FI on the GFS 18z tonight, this is a perfect way to end another fascinating day and night of model watching..in the week ahead some of us will be taking a keen interest in lamp posts and of course the netweather radar..wintry times ahead.

[SE Blizzards]

 

Something like this would do the trick

 

 

This is heading towards the idea the GEM was playing with for a few runs.

 

Oh, that's naughty, you've cheery picked a chart there CS!  lol

 

Looking at the 18Z ENS, there is a whole range of solutions in FI (as always) so i don't think anyone can say with any great confidence where we go after this colder spell that's due over the next few days.

Edited January 10, 2015 by SE Blizzards

[Eugene]

Well what a stonking FI on the GFS 18z tonight, this is a perfect way to end another fascinating day and night of model watching..in the week ahead some of us will be taking a keen interest in lamp posts and of course the netweather radar..wintry times ahead.

 

 

Yes a very promising run Frosty and definately not run of the mill.

Edited January 10, 2015 by Eugene

[Winter Cold]

What worries me though was fergies comment earlier about the longer range models they use. They are showing a return to SW winds later after next week. I know that can obviously (hopefully) change but is it possible the GFS etc arent seeing the correct signal yet. Still some good charts tonight from the 18z been posted, but they dont match the experts

[Tamara]

<We glean useful and very valuable insight into the stochastic processes that the METO adopt in longer term model ensemble assessment and perusal of background drivers. These form an obvious professional benchmark of opinion as a means to manage expectations within the thread, going forward, of what we might expect to see from forthcoming NWP output

 

<In addition to sharing enthusiasm of favourite weather types, the potential extra value (if we want to use it) of a format such as the MOD thread, is a free platform to push boundaries of the science and progress individual and collective learning.

 

< this takes us back to the dual benefits of the MOD thread being both a platform to indulge in sharing enjoyment of weather preferences - riding the hopes together of seeing favoured synoptics arriving in output - and the other benefit of learning and progressing knowledge through pushing the boundaries by using specialist 'weather tools' to make predictions.

 

<Both benefits should remain possible to achieve without recourse or recrimination when errors occur, and individual expectations carried within predictions are not met. In that respect, it is essential that predictions made balance both the preferences (the fun!!) and the realistic objectivity.

 

<Taking the 'weather preference' element out of the thread (whatever that preference may be) would lead to a very sterile and monochrome clone. On the basis that all members are human and have a myriad of individual personality, this is unrealistic to expect.

 

<As a voluntary website to participate in, no-one earns a wage here, so there is a luxury to indulge in both weather preference and hopefully objective study and prediction as a learning tool. However, as much as 'entertaining' any prospective audience keeps things buzzy and interesting, there is also a responsibility to make predictions realistic and objective and leave ego and reputation issues to the side (if there are any). This all helps avoid recriminations and backlash (toys out of the pram) when things don't verify according to plan.

 

<I think, imvho, remembering all these aspects could make this thread an easier place to participate in.

 

-------------------------------

 

Those extracts are of a post from New Years Day. Essentially, it means something is there for most of us if, we don't plant or impose our own will over those of others.

 

Many will obviously remember the days when Stewart (GP) was around. His background knowledge giving such incisive insight into the direction of future weather patterns and reading between the lines of model output evolution was certainly a flagship for cold weather hopes in the winter, but people might forget that his insight was always extended right through the other seasons in the year.

 

He was not just simply a 'cold ramper'. His understanding and learning would have been devalued after all, if he only simply deployed his forecasting techniques to the winter. Also, such insight is similarly devalued by calling a favourite weather type when plainly little hope exists

 

As a year round weather enthusiast, his posts were followed by a diverse range of weather watchers on net weather. Of course he embraced cold weather hopes most of all in winter - but that was perfectly in tune with the popular seasonal net weather audience.

 

His posts were mainly detached from human emotions to the weather, despite his own preferences and concentrated on the facts. This type of example I think, is key to the problem on this thread.

 

He however never passed up the opportunity to ramp when the cold was on our doorstep. His own excitement and anticipation is not to be forgotten back in 09/10 f.e   

 

In this way,  when popular seasonal weather is embraced, it might appear that other weather types which are actually (unfortunately!) more common in winter in the UK such as rain and gales, are overlooked.

 

Snow after all (at least for many on these threads in the winter) is totally magical, exciting, nostalgic (and also imo) romantic!!. It appeals to the inner child in us, however old we are. We also crave it more, the less we see of it. We forget its hazards outdoors that the average METO forecaster has to provide such impartiality to when forecasting. And yes I understand the possible perceived double standards for someone like me here, who doesn't like storms and destructive winds f.e.

 

The potential unbridled energy of nature is a fascination for all of us - whatever weather type we cherish....or dislike or even fear

 

On this basis, I think that favouritism is very forgive-able.

 

However, as stated above - it is still perfectly possible to embrace weather preferences with objective learning.

 

With that in mind, back to the models

 

 

 

[Jason M]

Although very low probability IMHO, I'd suggest something akin to this could provide light relief over the next few weeks.

 

http://www.meteociel.fr/modeles/gefs_cartes.php?code=14&ech=336&mode=0&carte=0

 

Probability? 10-20% in my view.... but I suspect more likely than a true arctic sourced northerly looking at the overall pattern.

 

This would probably finish Teits off as well (see below) 

http://www.meteociel.fr/modeles/gefs_cartes.php?code=14&ech=324&mode=2&carte=0

 

In set ups like that the snow doesn't get east of London! If it does, its usually game over and a rainfest!

 

It wouldn't be a long lasting set up as too much energy going over the top north of Scandi, but maybe the best that can be achieved from where we are now.

[Frosty.]

Yes a very promising run Frosty and definately not run of the mill.

Yes it's very promising, Tuesday shows a disturbance running across the south with snow falling in large parts of the UK to some extent, and more wintry weather to end the week, an upgrade from the 18z tonight..wintry weather is on the way..hooray.

[SE Blizzards]

<We glean useful and very valuable insight into the stochastic processes that the METO adopt in longer term model ensemble assessment and perusal of background drivers. These form an obvious professional benchmark of opinion as a means to manage expectations within the thread, going forward, of what we might expect to see from forthcoming NWP output

 

<In addition to sharing enthusiasm of favourite weather types, the potential extra value (if we want to use it) of a format such as the MOD thread, is a free platform to push boundaries of the science and progress individual and collective learning.

 

< this takes us back to the dual benefits of the MOD thread being both a platform to indulge in sharing enjoyment of weather preferences - riding the hopes together of seeing favoured synoptics arriving in output - and the other benefit of learning and progressing knowledge through pushing the boundaries by using specialist 'weather tools' to make predictions.

 

<Both benefits should remain possible to achieve without recourse or recrimination when errors occur, and individual expectations carried within predictions are not met. In that respect, it is essential that predictions made balance both the preferences (the fun!!) and the realistic objectivity.

 

<Taking the 'weather preference' element out of the thread (whatever that preference may be) would lead to a very sterile and monochrome clone. On the basis that all members are human and have a myriad of individual personality, this is unrealistic to expect.

 

<As a voluntary website to participate in, no-one earns a wage here, so there is a luxury to indulge in both weather preference and hopefully objective study and prediction as a learning tool. However, as much as 'entertaining' any prospective audience keeps things buzzy and interesting, there is also a responsibility to make predictions realistic and objective and leave ego and reputation issues to the side (if there are any). This all helps avoid recriminations and backlash (toys out of the pram) when things don't verify according to plan.

 

<I think, imvho, remembering all these aspects could make this thread an easier place to participate in.

 

-------------------------------

 

Those extracts are of a post from New Years Day. Essentially, it means something is there for most of us if, we don't plant or impose our own will over those of others.

 

Many will obviously remember the days when Stewart (GP) was around. His background knowledge giving such incisive insight into the direction of future weather patterns and reading between the lines of model output evolution was certainly a flagship for cold weather hopes in the winter, but people might forget that his insight was always extended right through the other seasons in the year.

 

He was not just simply a 'cold ramper'. His understanding and learning would have been devalued after all, if he only simply deployed his forecasting techniques to the winter. Also, such insight is similarly devalued by calling a favourite weather type when plainly little hope exists

 

As a year round weather enthusiast, his posts were followed by a diverse range of weather watchers on net weather. Of course he embraced cold weather hopes most of all in winter - but that was perfectly in tune with the popular seasonal net weather audience.

 

His posts were mainly detached from human emotions to the weather, despite his own preferences and concentrated on the facts. This type of example I think, is key to the problem on this thread.

 

He however never passed up the opportunity to ramp when the cold was on our doorstep. His own excitement and anticipation is not to be forgotten back in 09/10 f.e   

 

In this way,  when popular seasonal weather is embraced, it might appear that other weather types which are actually (unfortunately!) more common in winter in the UK such as rain and gales, are overlooked.

 

Snow after all (at least for many on these threads in the winter) is totally magical, exciting, nostalgic (and also imo) romantic!!. It appeals to the inner child in us, however old we are. We also crave it more, the less we see of it. We forget its hazards outdoors that the average METO forecaster has to provide such impartiality to when forecasting. And yes I understand the possible perceived double standards for someone like me here, who doesn't like storms and destructive winds f.e.

 

The potential unbridled energy of nature is a fascination for all of us - whatever weather type we cherish....or dislike or even fear

 

On this basis, I think that favouritism is very forgive-able.

 

However, as stated above - it is still perfectly possible to embrace weather preferences with objective learning.

 

With that in mind, back to the models

 

Quite simply the post of the day.

 

It's been quite an exhausting day of model watching, so on that note, I'd like to wish everyone a very peaceful goodnight.   

[Frosty.]

Quite simply the post of the day.

 

:

I still think Ian Brown's WTF, I don't know what to say takes some beating...haha

[Mark Bayley]

GFS 18z is as perfect example of what this set up can throw up. A snow event on Tuesday for anywhere the midlands north (probably the north Midlands/Yorkshire/NW favoured based on ensembles and both GFS). Of course, it may disapear, but shows with cold air in place surprises may happen! Admitidly with distance north and west. 

GFS P furthest north

[damianslaw]

It's been quite an exciting day today all round - with a lot to talk about, indeed the weather at the moment is probably at it's most changeable it can be at anytime of year - it reinforces the notion to me winter is the most exciting and interesting period of the year when we can go from one extreme to another in such short spaces of time.. days like today I think back to benign September, a woeful month in most years with hardly anything to talk about. There is no other season which brings about the level of passion that weather enthusiasts share and for this reason I love winter..

 

Back to the models - I've little to add from earlier comments, other than it is all about trends, and the theme is a path generally to colder weather outweighing milder weather. As ever take don't look at the details especially at the 240 hr range, the margin for error at such timescales is very large, even more so when under such volatile set ups as we are now.

 

We are beginning to enter the time of year I call 'mid winter' roughly 15th Jan- 15th Feb, when on average the UK experiences its coldest conditions of the year and when snow is most likely. We have time on our side for anyone hoping for colder weather - the saying goes as the days lengthen the cold strengthens, and the statistics back up the fact, the atlantic traditionally weakens during the second half of the winter and more blocked colder set ups are more likely to surface than zonal westerlies, February indeed can be the driest month of the year in the NW..

 

Others have commented on posts bemoaning the models and these shouldn't belong in this thread, and moved to the thread dedicated to such comments, I agree. Lets try to keep this thread dedicated to discussion of what the models are showing and leave bias for the other thread mentioned.

[Convective]

GFS 18z is as perfect example of what this set up can throw up. A snow event on Tuesday for anywhere the midlands north (probably the north Midlands/Yorkshire/NW favoured based on ensembles and both GFS). Of course, it may disapear, but shows with cold air in place surprises may happen! Admitidly with distance north and west. 

GFS P furthest north

 

I'd like to bank that one please!

 

[Mucka]

However (not a criticism of your post above)... This thread is titled "Model Output Discussion: Stormy Weather Inbound". Ergo, you'd think here was the *primary* forum to discuss model output for stormy weather, rather than being bounced to a separate thread. It has to be said that I read innumerable posts here expressing solely whether output is 'good' or 'bad' for snow... yet these don't get directed to a specific thread just for modelled snow-hopecasting. Major cyclogenesis is the single most eye-catching element within next few day's output and you'd rationally think would thus dominate model discussion...not get re-directed to a different thread.

 

 

I would of thought having a specific thread for a weather event emphasises it rather than the opposite?

I don't know, the world seems to be upside down these days, that's old age for you.

 

 

Get off my lawn!

 

The new liberalism is authoritarianism, no?

Edited January 11, 2015 by Mucka

[tinybill]

would  not be surprised  met office giving out  red warning  low seems to have deepened over  night now  935  mb

Edited January 11, 2015 by tinybill

[knocker]

A quick run through the GFS (P) this morning.

 

Out to T240 it is much the same picture of the interplay of the colder air to the north and HP to the south over the Atlantic. Thus still he battle between Pm and Tm although the former dominates giving generally colder than average temps with wintry incursions from the NW so still a N/S scenario regarding the UK. The jet is a tad further south but becomes disrupted.

 

The storm for Weds and Thurs is still on track and not looking that clever with a low 944mb over Scotland by 06z Thursday with winds in the region of 55-50kts.

 

A run through of the sequence.

http://weather.graphics/gsm/ygfs_t1534_global.php

Edited January 11, 2015 by knocker

[IDO]

The GFS op, P and C are all zonal through to D16:

 

  

 

That has been the trend from the GFS main runs of late. Any signal a few days ago for maybe something more interesting has toned down to a small cluster in the GEFS. Not as stormy as recent and next week, more like the baby ridge/trough combo of December, so TM and PM mixing it but favouring PM shots. Average to just below for the UK, temps and uppers wise. London:

 

 

 

Some consistency from GFS re the storm and there could be disruption on Thursday from that; op, C & P:

 

 

GEM has had a reboot and now more in line with other models though still a bit skittish. It is relativel flat most of the run and at D10: 

 

ECM is also flat for the next 10 days: 

 

As for the snow on Tuesday well the hi-res models make very little of it. The initial front tomorrow is rain and the following front fragments and there is very little snow:

 

 

So all in all the main issue is the storm next Thursday which could be dangerous (timing and location wise) however the models are still unsure as to track and size yet. Other than that a cool period from GFS out till the last few days of January there is little of interest showing up bar the storm.

Edited January 11, 2015 by i'm dreaming of...

[knocker]

The ECM has a slightly different take on the storm.

 

At 18z on Weds it has the low 962mb just west of N. Ireland giving severe SW winds up the Irish Sea. The low has moved east to just north of Ireland by 00z Thursday and the belt of very severe winds has crossed England into the North Sea.

[Nick F]

Well it looks like the mobile Atlantic-driven yo-yo looks set to continue unabated through towards the end of Jan, it's easy to loose track of the milder and colder interludes as each system arrives and moves on, trending more in the way of colder interludes rather than mild this coming week. 

 

With regards to snow, increasing potential for back edge snow events Tuesday onwards with any cold fronts plus the usual wintry showers in the PM flows for Scoltand, N. Ireland,  along with windward northern and western coastal areas elsewhere. Any back edge snow events away from favoured northern areas difficult to predict this far off, so will become clearer nearer the time.

 

Most models agree on Wednesday nights deep low tracking NE somewhere across Scotland, quite concerning with regards to widespread risk of strong winds near along/cold front, GFS indicating 60-70mph widely, perhaps 70-80mph+ with exposure. Then another bout of strong winds across central areas following the front, on the southern flank of the low crossing Scotland.

 

 

Beyond that, GFS op/P and UKMO have a brief cold northerly toppler next weekend, ECMWF doesn't.

 

Not let up from the trop vortex to the north and NW driving a zonal/mobile flow bringing yo-yo mild/cold interludes with more wind, rain and wintriness at times, GFS op/P even point to it strengthening to our NW later this month, but ECMF does seem to shift the trop vortex east away from Greenland across the Norwegian Sea towards Scandi.

 

And from the NH view you can see bulk of low heights over Scandi and Siberia at day 10, which is kinda of a good thing:

 

http://www.wetterzentrale.de/pics/Recmnh2401.gif

 

As per yesterday's MJO forecasts - consensus appears to take MJO either into COD from phase 6 or into 7 at a very low amplitude, so the weak MJO signal not really having an effect on amplifying the flow too much as we head through late Jan. So it's hard to see a pattern changer for now, other than hints that the PV may migrate away from N Canada and Greenland toward Scandi and Siberia - which is one positive.

Edited January 11, 2015 by Nick F

[Captain Shortwave]

Looking at the output this morning, I suspect the chance of a northerly is falling for next weekend, which is a shame as this would have places eastern areas in with a chance of snow from showers moving in off the north we. ECM and GEM are pretty flat with just another cold PM west/north westerly following the storm on Thursday.

 

Beyond this, we continue to see a chilly and unsettled pattern with the risk of wintry precipitation at times in the north (even at low levels). Further south, it may be a case of hopping to get lucky from any secondary low develops as they zip eastwards along the base of the trough.

ECM ens show the jet south of the UK with a west/north west flow persisting with milder spells being very brief (12-24 hours at most at a time). For a more widespread colder pattern we need to tilt the jet more north of west than is currently modelled. Overall, still good for western and northern areas. Not particularly great for everyone else.

[Man With Beard]

would  not be surprised  met office giving out  red warning  low seems to have deepened over  night now  935  mb

Fortunately this is probably the most extreme chart, most op runs slightly less severe, though unlikely to pass without a little disruption.

That aside, a blustery week ahead, rain on several days, temperatures probably low enough at timed for hill snow in the south and more widespread but shortlived snow in the north from time to time. More late developing storms can't be ruled out.

Hard to see any mild weather in the next ten days, but with high pressure to the south and low pressure to the north on most runs by D10, and a repeating pattern of the PV returning to Greenland I'd say mild more likely than cold thereafter - to say anything else requires reading into things not visible on most models IMO.

[Gibby]

HERE IS MY LATEST ANALYSIS FROM THE OUTPUTS OF THE WEATHER COMPUTER PREDICTION MODELS FOR TWO WEEKS FROM 8AM TODAY SUNDAY JANUARY 11TH 2015.

NEXT UPDATE MONDAY JANUARY 12TH 2015 08:00

THE CURRENT GENERAL SITUATION A strong Westerly flow will back SW and strengthen further later today and tonight before a cold front sweeps SE tomorrow stalling across Southern England later.

MODELS-2 WEEK HEADLINE Continuing mostly unsettled with rain or showers at times. Near average temperatures will fall rather cold at times with some snowfall at times on all higher ground.

THE JET STREAM ENSEMBLE FORECAST The Jet Stream Forecast shows a very strong Jet Stream this week weakening slowly thereafter. There will be plenty of cold zonality type weather as the Jet lies South of the UK through Week 1. Through the second week the Jet flow shows signs of drifting back North with pressure rising slowly from the South bringing back more lengthy incursions of tropical maritime damp and drizzly conditions late in the period.

GFS OPERATIONAL The GFS operational shows a very disturbed week to come with a very strong Westerly airflow blowing across the UK with fronts rushing East in the flow bringing spells of cold and showery weather with snow on hills. A deep Low close to midweek brings a brief spell of less chilly and wet weather and severe gales before a general cold and showery pattern develops late this week and next weekend as winds veer slowly North. Then the latter stages of the run are dominated by a pattern reset as the cold ridge collapses and Westerly winds with rain and wintry showers at times returns.

THE GFS PARALLEL RUN The Parallel run is broadly similar in the sequence of events throughout the period with cold zonality the order of the day through the second week as further depressions crossing East to the North of Scotland. There is signs of a pressure rise across Southern Britain at times tempering the strength of the Westerly flow here occasionally with calmer and more benign conditions under less contrasting temperatures day to day.

THE GFS CONTROL The GFS control run too shows that Westerly winds under polar maritime air rules the roost throughout it's run this morning with a brief cold Northerly next weekend when snow showers could fall for quite a few and frost at night could return. At other times rain and showers will fall wintry at times as cold NW'lies replace milder Westerly incursions, these especially in the South.

THE GFS CLUSTERS The GFS Clusters today show a mix of options surrounding an Azores High pressure and Low pressure to the North and NE of the UK. The bias of output favours a cold polar maritime airmass most likely with wintry showers in rather cold conditions though some clusters support more influence from an Azores ridge or also from deep Low pressure to the NW with milder SW winds as a result.

UKMO UKMO shows a strong Westerly flow towards midweek with wintry showers in rather cold conditions. Later in the week a deep depression crosses Scotland bringing wet and possibly quite stormy conditions for a time before West then NW winds return with with wintry showers again towards next weekend.

THE FAX CHARTS The Fax Charts shows a continuing changeable theme surrounding two types of weather. There will be spells of cold weather under Westerly winds and wintry showers while a deepening depression crosses ENE across Scotland soon after midweek and followed by a return to cold Westerly winds and wintry showers.

GEM GEM today shows very disturbed weather across the UK through the next 10 days peaking at the point soon after midweek as another major storm system crosses ENE over Scotland later on Wednesday and Thursday with sever gales and heavy rain for all. Most of the rest of the time will be spent under rather cold and showery Westerly winds with snow on hills at times while further brief wet and windy periods occur too under a very volatile and mobile Atlantic flow.

NAVGEM NAVGEM reflects the storm system midweek too with rain and strong winds interrupting a spell of cold westerly winds before and afterward before a ridge of High pressure crossing East next weekend brings a breather from the strength of the Westerly flow for a day or two with some bright and sunny spells in places.

ECM ECM this morning also shows a lot of strong Westerly winds with spells of rain and wintry showers to come for all especially across the North. As with all other models it too shows a storm system midweek with very wet and windy weather for all for a time. Then cold and showery weather returns and lasts for some time before a weakening of the flow promotes quieter conditions towards the end of the run as milder air and SW winds encroach with some rain in places slowly from the South-West at the start of Week 2 .

ECM 10 DAY MEAN The ECM 10 Day Mean Chart overwhelmingly maintains the likelihood that cold polar maritime winds from the West or NW around deep Low pressure to the North and a trough over Europe is the most likely scenario with the Jet stream well South of the UK. Sunshine and wintry showers and some longer spells of rain and sleet would be the common weather forecast surrounding this pattern..

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The trend this morning no real change in maintaining a basic Atlantic driven weather pattern across the UK over the next two weeks.

MY THOUGHTS While I cannot promise anything particularly wintry in any one place over the period there is plenty of weather to come across the UK over the next few weeks including some snowfall from a very active Atlantic and powerful Jet Stream having now moved further South than recently. The general theme of the weather this week will be one of cold Westerly winds carrying plenty of Wintry showers once tomorrow's cold front clears the South. The showers will fall as snow on all high ground, low ground too in the North and could give some disruption in places. Some snow could affect the moors of the SW at times too though Eastern parts with shelter should largely escapse dry and bright. Then soon after midweek a deepening Low pressure crosses the UK. All models have firmed up on this feature, crossing it ENE over Scotland at around 965mbs which is less deep than previously feared. Nevertheless, this is sufficient to give all areas a good gale with svere gales in exposure along with milder air and heavy rain briefly. The cold showery weather then returns and then all models show a varying degree of extent to a weekend ridge, veering winds into the NW or North, drying things out for a while with overnight frost. Later in the run it then looks the overlying support remains for the Atlantic to continue to dominate with rain and wind on occasion mixed with cold weather with wintry showers in Westerly winds. Despite my frequent use of the 'wintry' and 'snow' word nowhere in lowland Britain should experience anything more than transient snowfall through the whole period and this most likely in the West and North and on the hills and moors from SW England northward while many Eastern areas away from the bands of wind and rain could see a lot of dry and bright weather under the straight and cold Westerly flow, offered protection from the West. While not wintry armageddon there is a lot of interest on the synoptics at present and almost anywhere could see a surprise snowfall over the period especially this first week. This flavour of Winter is the best we can hope for though currently as there looks little desire to bring anything long term and direct from either the North or East with pressure to the SW of the UK throughout remaining persistent and stubbornly strong.

[mushymanrob]

whats this? early hints of pressure rise over scandinavia?

 

 

perhaps the start of something... more runs needed of course.

[bluearmy]

well there is no swing back on the extended eps this morning. If anything, it's support for the glosea/MOGREPS return of WSW zonality towards day 14 has slipped a bit.

of course, the output post day 10 is always subject to some tweaks but if we don't see a snow event over a fairly large part of the country in that 11/14 day period, I will be surprised..

Hints of the ridge following the sinking trough allowed to become a decent n Atlantic feature. no idea what the clusters show but the combination of slow sinking mean trough, lowish SLP and thickness in the 525/530 area is something we haven't seen for a long time.

I think we will have to rely on secondary features running into or around the troughing to deliver an event but at this time of year, even innocuous looking output can deliver under a slackish cold anomoly.

the gefs make a bit more of the Azores ridging which means we see the alternating cold with mild blips as warm sectors come through. I suppose the biggest illustration of this being around day 12/13 where gefs brings a mean ridge through with 552 dam touching the south coast.at that point, ECM has the south coast firmly under the trough with 534 dam on the coast. Actual thickness conrast from 530 on ECM to 536 on gefs. plenty to firm up on but seems likely that we will see a decent wintry period beginning with the storm midweek.

Rob, that mean upper ridging has been showing for a while in the svaalbard area. it very shallow though and is splitting the Siberian/Canadian vortices. I say splitting, but it's quite a weak split with the Alaskan ridging the other side far more evident. It does help to sink the troughing in our vicinity though.

Overall, I just like what I'm seeing from a coldie perspective. not sure the Canadian vortex is going to go absentia though. It can hang around Far nw Greenland if it stays weak though.

Edited January 11, 2015 by bluearmy

[Isabellesnanny]

Hope this is not too off topic but wonder if anybody could assist. Presumably organisations like the Met have more tools to look at than the general public however presumably in the main they are looking at a lot of the same models.

On a site like this we can sometimes see that two people can look at a model and see totally different things therefore I wondered bow much human input there is to analysing the data as obviously they do not issue raw output - again sorry if off topic just curious.