Model Output Discussion - 16th Jan 12z onwards - Smile While You Post!

[Ice Day]

Brilliant post Ian, however regarding point 9....

 

9. Thus, can we desist from further forum freak-outs today...! :-)

 

You have two hopes of that happening, 'Bob' and 'No'!

 

Anyway, back to the models and thankfully there has been a swing back towards a colder outlook by the GFS and ECM, hopefully the UKMO will look a little better later.  It looks like FI is around 96-120 so pointless looking any further (unless it's showing a raging easterly at 360 when clearly it will verify!!!).

 

Right, back later for the 18z.....please don't let us down!

[snowice]

Seeing as it's nice and early in the day, perhaps we can see the remainder of Saturday through without the hysterics expressed on the forum yesterday?

Critical points of note are simple:

1. Amplified upper pattern remains favourable for (two) trough disruption(s) early-mid next week

2. Scope of how and where these may occur will NOT be correctly resolved in ANY model at this lead time

3. Ergo, any over-analysis is pointless at this lead time given great uncertainty and variance/volatility in model handling

4. Likely erratic and eventually weakening E'ward progress of occlusion into cold air Tues means uncertainty on areal spread of snow: GFS PPN phase charts to be viewed with due caution.

5. Risk of rain onto frozen surfaces even where no snow. Varied wintry hazards look inevitable but no compelling evidence for a 'nationwide snow event' in strict defined sense. However, threat of disruptive snow for some areas (starting in parts of NI initially under frontal mass ascent; then W Scotland and Wales) is quite obvious, although no regional detail is reliable for now.

6. The potential for some easterly flow later into the week could not be *wholly* discounted yesterday (despite some claiming so); nor again in this morning's output, albeit still considered a lower probability outcome (ca. 40% support for some easterly component in 00z MOGREPS-G)

7. Attempt to resume westerly mobility later in the week (Weds-Thurs, powered by strong jet) may threaten further snow with second trough disruption. Importantly, the transition/timing and evolution of this switch will inevitably be messy and poorly resolved in all models currently.

8. Further swings in output are a given, as models struggle with upstream driving developments in W Atlantic/US.

9. Thus, can we desist from further forum freak-outs today...! :-)

Honest, reasonable, factual, accurate description of latest output.Hope this will make for a great model discussion and yesterday's moans was just a blip lol! Edited January 17, 2015 by snowice

[nick sussex]

The models are really determined to drag this whole drama out, even if the snow does come many in here will be too exhausted to enjoy it!

 

At least this morning we've seen an upturn in potential although the UKMO is still less than interested, the ECM is better, the GFS although bringing in less cold conditions sooner than the ECM has improved in the shorter term.

 

In these circumstances with slider lows smallish changes early on can collectively make a big difference later, if the first slides further west then the second is also likely to follow the same path because your base mark is the first slider.

 

You'll see after the initial occluded front working east the ECM has two sliders one between T96 and T120hrs and another from T144hrs to T168hrs, so I think its pretty crucial what the models do with that T96hrs one.

 

The ECM positively keeps low heights over northern Italy to 216hrs although weakening by then, as long as you maintain those the UK is likely to stay cold.

 

Given the volatility of the outputs in recent days its likely there will be more changes, theres a very fine line between snow and rain , I certainly don't want to see some oil rig in the North Sea stealing all the UK's snow so hopefully the models will  bring the pattern a little further west.

[Barking_Mad]

Oh I love it when Ian's all masterful. Lol delete/ban/bin.

Edited January 17, 2015 by Barking_Mad

[Mair Snaw]

Seeing as it's nice and early in the day, perhaps we can see the remainder of Saturday through without the hysterics expressed on the forum yesterday?

Critical points of note are simple:

1. Amplified upper pattern remains favourable for (two) trough disruption(s) early-mid next week

2. Scope of how and where these may occur will NOT be correctly resolved in ANY model at this lead time

3. Ergo, any over-analysis is pointless at this lead time given great uncertainty and variance/volatility in model handling

4. Likely erratic and eventually weakening E'ward progress of occlusion into cold air Tues means uncertainty on areal spread of snow: GFS PPN phase charts to be viewed with due caution.

5. Risk of rain onto frozen surfaces even where no snow. Varied wintry hazards look inevitable but no compelling evidence for a 'nationwide snow event' in strict defined sense. However, threat of disruptive snow for some areas (starting in parts of NI initially under frontal mass ascent; then W Scotland and Wales) is quite obvious, although no regional detail is reliable for now.

6. The potential for some easterly flow later into the week could not be *wholly* discounted yesterday (despite some claiming so); nor again in this morning's output, albeit still considered a lower probability outcome (ca. 40% support for some easterly component in 00z MOGREPS-G)

7. Attempt to resume westerly mobility later in the week (Weds-Thurs, powered by strong jet) may threaten further snow with second trough disruption. Importantly, the transition/timing and evolution of this switch will inevitably be messy and poorly resolved in all models currently.

8. Further swings in output are a given, as models struggle with upstream driving developments in W Atlantic/US.

9. Thus, can we desist from further forum freak-outs today...! :-)

Fantastic post with some valuable incite/information..... it maybe a good idea to inbox this in bold to every member....

[snowking]

Ha - well put Ian but I fear point 9 will come unstuck faster than a disappearing easterly!

Incidentally, having taken my eye of strat developments recently, and with another 6 weeks left of meteorological winter with March to follow, it seems we may get a wintry shove from that direction if the currently predicted upper strat pattern is reflected in the trop next month. Siberian vortex. No Canadian vortex. fill in the blanks.

RE: strat

Posted a couple of days ago about this so I'm glad that consistency has remained (I too have not had a chance to monitor inter-run consistency on this)

However my fear with this, tropospherically, is how much energy around the Greenland locale gets left behind - obviously far too far away at this juncture to put any sort of accuracy on that given recent model trends to underestimate energy in that area (apparent even from events over the last few days) before correcting closer to T+0.

But with a really rather disjointed vortex it really isnt taking much to budge it across to the Siberian sector - the wave 1 that appears responsible is not hugely impressive in scope but still manages to do the trick according to current forecasting.

So a potential return to something a little more mobile whilst this transition takes place seems fairly likely at this stage. Im sure some members will be sick of people saying this this winter, but what we see the other side of this is the best potential for some sort of blocking based to our North-West for some time.

Of course question marks remain on the transition tropospherically given the building Siberian high, and ongoing uncertainty (due to rather poor mid-term modelling) surrounding the progression of the MJO and any over-riding effects this could have.

SK

[nick sussex]

You can see by the ECM postage stamps to T120hrs why this is high stakes for cold and snow lovers:

 

 

Theres lots of different solutions , some good and some downright ugly in terms of cold potential.

 

Thankfully the ugly ones are very much in the minority, but theres some which will likely bring some snow initially then less cold, snow and further snow, some likely to bring in a slackish easterly. There really are several different avenues that those members could go in past T120hrs.

 

 

 

[Eugene]

Seeing as it's nice and early in the day, perhaps we can see the remainder of Saturday through without the hysterics expressed on the forum yesterday?

Critical points of note are simple:

1. Amplified upper pattern remains favourable for (two) trough disruption(s) early-mid next week

2. Scope of how and where these may occur will NOT be correctly resolved in ANY model at this lead time

3. Ergo, any over-analysis is pointless at this lead time given great uncertainty and variance/volatility in model handling

4. Likely erratic and eventually weakening E'ward progress of occlusion into cold air Tues means uncertainty on areal spread of snow: GFS PPN phase charts to be viewed with due caution.

5. Risk of rain onto frozen surfaces even where no snow. Varied wintry hazards look inevitable but no compelling evidence for a 'nationwide snow event' in strict defined sense. However, threat of disruptive snow for some areas (starting in parts of NI initially under frontal mass ascent; then W Scotland and Wales) is quite obvious, although no regional detail is reliable for now.

6. The potential for some easterly flow later into the week could not be *wholly* discounted yesterday (despite some claiming so); nor again in this morning's output, albeit still considered a lower probability outcome (ca. 40% support for some easterly component in 00z MOGREPS-G)

7. Attempt to resume westerly mobility later in the week (Weds-Thurs, powered by strong jet) may threaten further snow with second trough disruption. Importantly, the transition/timing and evolution of this switch will inevitably be messy and poorly resolved in all models currently.

8. Further swings in output are a given, as models struggle with upstream driving developments in W Atlantic/US.

9. Thus, can we desist from further forum freak-outs today...! :-)

 

One of the best posts on here ever, lets get this upto 100+ likes folks.

[Long haul to mild]

Ian F's post definitely shows the high degree of uncertainty at the moment re developments during next week and certainly a pragmatic and patient approach is the way forward.

 

As bluearmy mentioned earlier, it is likely to be tomorrow before the models really start to get a handle on the placement of low pressure on Tues/Weds, but even then the snow/rain question will still be very hard to call until very close to the time, same with the Eastward extent and intensity of any precipitation.

 

Therefore I hope people take a step back and consider these factors when looking at the output today. I myself had a wobble last night because I allowed the GFS 18Z to affect my judgment; because of where I am, I don't take well to Easterlies suddenly disappearing and being replaced by Westerlies! However, I know deep down that these kind of synoptic setups are volatile so my lesson is learned!

[WINTRY WALES]

But with a really rather disjointed vortex it really isnt taking much to budge it across to the Siberian sector - the wave 1 that appears responsible is not hugely impressive in scope but still manages to do the trick according to current forecasting.

SK

Hi CC or anyone else who can reply

Sorry for being a bit dumb on this matter but ideally where would we want the vortex to setup to enable blocking to our North West to occur??

Would we want the vortex to set up as one in this locale? Or split and have a daughter vortex in this location?

sorry for the confusion and if in the wrong thread....just wanted to keep an eye on this in future model output.

Regards WW

Edited January 17, 2015 by WINTRY WALES

[Cloud 10]

You can see by the ECM postage stamps to T120hrs why this is high stakes for cold and snow lovers:

 

120.gif

 

Theres lots of different solutions , some good and some downright ugly in terms of cold potential.

 

Thankfully the ugly ones are very much in the minority, but theres some which will likely bring some snow initially then less cold, snow and further snow, some likely to bring in a slackish easterly. There really are several different avenues that those members could go in past T120hrs.

 

The GEFS spreads at 120 hrs pretty much sums it up,with the UK being at the center of uncertainty across the Northern hemisphere.

 

[bluearmy]

RE: strat

Posted a couple of days ago about this so I'm glad that consistency has remained (I too have not had a chance to monitor inter-run consistency on this)

However my fear with this, tropospherically, is how much energy around the Greenland locale gets left behind - obviously far too far away at this juncture to put any sort of accuracy on that given recent model trends to underestimate energy in that area (apparent even from events over the last few days) before correcting closer to T+0.

But with a really rather disjointed vortex it really isnt taking much to budge it across to the Siberian sector - the wave 1 that appears responsible is not hugely impressive in scope but still manages to do the trick according to current forecasting.

So a potential return to something a little more mobile whilst this transition takes place seems fairly likely at this stage. Im sure some members will be sick of people saying this this winter, but what we see the other side of this is the best potential for some sort of blocking based to our North-West for some time.

Of course question marks remain on the transition tropospherically given the building Siberian high, and ongoing uncertainty (due to rather poor mid-term modelling) surrounding the progression of the MJO and any over-riding effects this could have.

SK

Yes kris - tropospherically, the split by day 10 is closing as energy heads back across from Siberia to Canada. This no doubt responsible for the uptick in the northern arm post day 10 modelling. how we would get the majority of the trop vortex back to Siberia promotes some big questions. can't see it myself and if it does happen, it will again uptick that Atlantic jet - unless we have some blocking in just the right place, that tells it's own story. However, it doesn mean we couldn't see a scenario as the current one playing out. Edited January 17, 2015 by bluearmy

[Gibby]

HERE IS MY LATEST ANALYSIS FROM THE OUTPUTS OF THE WEATHER COMPUTER PREDICTION MODELS FOR TWO WEEKS FROM 8AM TODAY SATURDAY JANUARY 17TH 2015.

NEXT UPDATE SUNDAY JANUARY 18TH 2015 08:00

THE CURRENT GENERAL SITUATION A slackand cold airflow across the UK today. A frontal trough will move up over the English channel tomorrow.

MODELS-2 WEEK HEADLINE Rather cold and unsettled with rain or snow in places. Frost at times.

THE JET STREAM ENSEMBLE FORECAST The Jet Stream Forecast shows the flow rather weaker than o flate though sufficiently strong to maintain a generally Atlantic driven pattern of cold zonality with the positioning of the flow remaining South of he UK and troughed down over Europe towards the Meditteranean.

GFS NEW OPERATIONAL The GFS operational continues to project rather cold and unsettled conditions across the UK with the weather determined by disturbances coming SE down over the UK from the NW. There will be extended periods of rather cold and unsettled weather with showers or longer spells of rain, sleet and snow interspersed with clearer weather with wintry showers and frosts at night. with little sign of any pattern change right out to the end of the run and beyond.

THE GFS CONTROL The GFS control run also shows rather cold and unsettled weather in the first week with Low pressure feeding SE across the UK with rain, sleet or snow and wintry showers for all. Next weekend shows a marked ridge deliver a cold and frosty period before a more Atlantic driven Westerly with rain at times takes hold with less cold conditions overall though still chilly enough for wintry showers on Northern hills at times.

THE GFS CLUSTERS The GFS Clusters show strong support for cold zonality conditions to be the more likely weather pattern we find ourselves in two weeks from now. Low pressure to the North and East of the UK is shown by 65% of  the pack while the other 35% a more traditional less cold zonal pattern under westerly winds with a 15% support for High pressure to lie close to Southern Britain in 14 days time.

UKMO UKMO this morning shows a period of trough disruption over or to the East of the UK. A band of rain, sleet and snow will spread East towards midweek followed by a chilly NW flow with showers with hints of a recurring pattern later on in the week as new Low pressure to the North sends troughs SE.

THE FAX CHARTS The Fax Charts illustrate a complex pattern synoptically over the UK for the next 5 days or so. Various weak troughs at first will give rise to some rain or sleet in the South while the West receives the risk of this on Tuesday spreading East under an occlusion and giving some snow in places. then a cold NW flow with wintry showers follows this trough midweek.

GEM GEM today shows a cold and unsettled week to come as Low pressure slides SE down across the UK from the NW. Under the extensive cold air lying across the UK such Low pressure and troughs will deliver spells of rain, sleet and snow with some disruption possible towards the North and East in particular. A strong ridge next weekend bringing sharp frosts and sunny days then sinks away South to allow milder Westerly winds with rain at times to end the period.

NAVGEM NAVGEM keeps the rather cold and unsettled weather going throughout this morning's run as Low pressure areas slide SE over Eastern Britain or the North Sea. Spells of rain and sleet would be succeeded by sunshine and wintry showers in a blustery NW wind at times.

ECM ECM this morning too maintains a rather cold outlook with the weather powered by successive pushes of Low pressure down over or just to the East of the UK, each bringing their own version of unsettled conditions with showers or longer spells of rain, sleet and snow in strong and blustery winds from the NW at times. At the end of the run it looks like a rinse and repeat pattern is setting up to continue the theme beyond the time parameter of the run.

ECM 10 DAY MEAN The ECM 10 Day Mean Chart continues to show a similar evolution on each output with the chart made up of plenty of cold zonality options made up of Low pressure to the North and down across NW Europe to the Med. It therefore looks like continuing rather chilly weather with rain or showers falling as sleet or snow at times is the most likely outcome 10 days from now.

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The differnces in trend today focus on moving the axis of the disrupting troughs further East than yesterday morning towards Eastern Britain and the North Sea with the UK under a chilly NW flow for much of the time.

MY THOUGHTS I can see where some of the disappointment lies within the cold fraternity this morning in that it wouldn't take too much to lock the UK into a cold and snowy picture for a week or so if we fell on the right side of the disrupting Low pressure zones as they move SE from the NW. As it is the models have firmed up somewhat in putting the axis at a point over or just to the East of the UK meaning the UK will rely on the cold and chilly NW flows on the West side of the disrupting troughs to deliver cold weather with wintry showers through the week outside of the periods of trough disruption. It is a fact though that with cold entrenched across the UK by midweek that trough disruption is very difficult for computer models to predict accurately in advance and sometimes they can be too progressive in displacing the cold away to the East. However, at the moment we have to go on what we see and that is a spell of rain, sleet and snow for all as the first trough disrupts within the vicinity of the UK clearing to wintry showers as the NW flow behind the front is also very chilly. It then looks very probable that further troughs will also slide SE towards NW Europe repeating the pattern late in the week before there seems reasonable support for High pressure to ridge across the UK next weekend settling things down for a time with frost and freezing fog patches by night but bright and sunny days. Looking further ahead still is fairly futile to be honest being with such fluid dynamics of this coming week making any longer term predictions suspect to say the least but going on what's on offer this morning apart from a brief milder interlude in 10 days or so further cold zonality with rain or snow at times in Atlantic winds blowing North of West for much of the time seems the favoured plan longer term for now. As the cold spell goes it is going much the way as I expected to be honest as I have never bought in to widespread disruptive snowfalls across the UK that some on the forums have amplified. There are a few missing vital pieces to the jigsaw required to bring such events with the lack of High pressure to the NE to enhance the cold block of air currently in place over the UK and NW Europe plus of course our old friend the Azores High lurking around too encourages a shift East of any cold pattern. Nevertheless and interesting and fascinating period of model watching is maintained and I can guarantee there will be many more twists and turns towards mild and colder options shown within the outputs of the coming week before any longer term resolution can be guaranteed. So sit back enjoy the ride and remember the more time spent looking at every frame from every model run takes away the time you could be spending watching the cold weather you love so much carry on outside of your own windows. It is only the weather and is thankfully totally beyond our control.

[damianslaw]

What an enjoyable read this particular page of this thread has been, compared to most pages we had to suffer yesterday. Some excellent objective postings from many, I put the time of day down to this, mornings are always more pleasurable it seems than the peak period between 9 and 11 pm when things always seem to go crazy - which during the week is the only time I have chance to browse.

 

Yes lots of options on the table and none of the models will have it right at this timescale what happens at the 72-96 hr timeframe which will have knock on implications thereafter - reliable timeframe is very short at moment, 72 hours tops.

 

I've seen many a front struggle to make inroads to the east of the country in such a set up, some indeed have fizzled in situ, many have stalled, some have even been forced to backtrack westwards - 6 Feb 96 being a classic example.

 

Longer term - background signals suggesting the core of the PV will move towards Siberia which would open up chance of heights building to the NW, but this do appears at odds with current prediction for strengthened Siberian high - who knows a lobe of the PV may be forced to drop into Scandi with fragments fired our way...

 

I'm tempted to dip into this thread just one more time today - probably later, for fear of being very frustrated with nature of postings again - though I've observed how Saturdays tend to see the most positive postings of the week on average, compared to Sunday evenings which are often very depressing I wonder why!

[Pembroke Dangler]

Seeing as it's nice and early in the day, perhaps we can see the remainder of Saturday through without the hysterics expressed on the forum yesterday?

Critical points of note are simple:

1. Amplified upper pattern remains favourable for (two) trough disruption(s) early-mid next week

2. Scope of how and where these may occur will NOT be correctly resolved in ANY model at this lead time

3. Ergo, any over-analysis is pointless at this lead time given great uncertainty and variance/volatility in model handling

4. Likely erratic and eventually weakening E'ward progress of occlusion into cold air Tues means uncertainty on areal spread of snow: GFS PPN phase charts to be viewed with due caution.

5. Risk of rain onto frozen surfaces even where no snow. Varied wintry hazards look inevitable but no compelling evidence for a 'nationwide snow event' in strict defined sense. However, threat of disruptive snow for some areas (starting in parts of NI initially under frontal mass ascent; then W Scotland and Wales) is quite obvious, although no regional detail is reliable for now.

6. The potential for some easterly flow later into the week could not be *wholly* discounted yesterday (despite some claiming so); nor again in this morning's output, albeit still considered a lower probability outcome (ca. 40% support for some easterly component in 00z MOGREPS-G)

7. Attempt to resume westerly mobility later in the week (Weds-Thurs, powered by strong jet) may threaten further snow with second trough disruption. Importantly, the transition/timing and evolution of this switch will inevitably be messy and poorly resolved in all models currently.

8. Further swings in output are a given, as models struggle with upstream driving developments in W Atlantic/US.

9. Thus, can we desist from further forum freak-outs today...! :-)

Amazing post and from what I can pick out of this could it be that westward corrections are coming into play which is similar to what occurred back in January 2013 where the models 4 days out were too progressive and then suddenly at just t12 it was only an event which got as far as Birmingham before heading south into France followed by another attempt which was the same! I'm punting on westward corrections again!

[Smiler1709]

Nice report Gibby, my thoughts exactly regarding enjoying it while it's here, we only have frost but I'm happy.

I think whats evident is that the models are firming up on bring cool/mild weather back to our shores by midweek, but with all if feb to play for and a nice cold pool to our right hopefully we can just have one good easterly before winter ends.

[West is Best]

I'm putting this in the model discussion because I think it's pertinent. It's snowing here in Norfolk at the moment with a temp of 0C and dew point of -2C. Temperatures in the south-east overnight were much lower than being forecast even as late as the 00h05 BBC online forecast. That's because cloud cover was not as expected. The point of this, tying in with Ian's point, is that the 3 main models are fairly blunt instruments when it comes to 'will it snow at xx place at yy time.' They are best used for daily or perhaps at most 12 hourly pattern indicators. The finer detail comes down to other factors and forecasts. The Met Office have had a particular struggle with the straddling occluded front in the channel for the past 72 hours, and yet the finer positioning of that (currently only just clipping the south coast) could make the difference between nothing or a significant situation: fine changes make a big difference on the ground.

 

So, although I don't share the love for the long-term outlook 7 days from now, all three overnight 0z models, and particularly GFS and ECM continue to show snow potential for some places from here to then. Which ones and when may come down to an hour before. And I write that looking out on a very beautiful sight of large snowflakes falling from the sky. Have hope.

Edited January 17, 2015 by West is Best

[sunnijim]

Nice report Gibby, my thoughts exactly regarding enjoying it while it's here, we only have frost but I'm happy.

I think whats evident is that the models are firming up on bring cool/mild weather back to our shores by midweek, but with all if feb to play for and a nice cold pool to our right hopefully we can just have one good easterly before winter ends.

Take the time to read the excellent analysis here this morning.Your last paragraph has no relation to what the models show or what experts here are saying,it does infact mislead which i'm sure was not your intention.

Quite how you see a ruturn to "cool/mild" by Wednesday is beyond me!

Edited January 17, 2015 by sunnijim

[The Beast From The East]

When Glacia Point said he was moving on I like the majority on here was gutted because he had so much noalage and always could give us a good idea on what was likely to happen even when the models might have been showing something different to what we were expecting or hoping to see.

Well what a relief when

This man joined the forum

#306 fergieweather

Members

1,325 posts

Gender:Male

Location:North Somerset, UK

It's great to have someone from the met office taking time out to come here and share any information he has on the up and coming weather.. I'm a complete novice and struggle to read the models but I'm on here daily trying my best and taking notice from the likes of Steve Murr, Tetis(eye in the sky), nick Sussex , Tamara to name but a few. Plus all this wouldn't be possible with out this fantastic site and all the moderators who keep an eye on the forum daily . Net Weather.. Big thank you .. ⛄

Just needed to get all that of my chest.. Anyway I'm a lot happier this morning looking at the models as they seem to have shifted back to a colder week with the possibly of snow turning up all most anywhere.

P.S ... Hope that one day Glacia Point may come back on here and pay us all a visit.

[IDO]

The ECM op at D8 (so probably starts D5+) is progressive with the breakdown of the trough by the Azores Ridge:

 

Compared to the mean

 

So that means the ECM looks like another typical op outlier for temp at D9 plus:

 

Mean OP

 

In theory then even better prospects for maybe another 2-3 days of cold, especially for the east. So a good ensemble suite as I would expect the UK to be affected by two sliders. Lots of scatter after D8 on the De Bilt, which is no surprise:

 

 

The GEM control at D7 is an excellent trend:  

 

About 33% of the members show a slack easterly at D8 on the GEM ensembles, not a million miles away from the MOGREPS. Still some uncertainty but a move in the right direction at the right time.

Edited January 17, 2015 by i'm dreaming of...

[bluearmy]

Extended ECM eps mean/anomolys fairly consistent with yesterday's 12z . Jet nw/se axis with the through into e Europe. N Russian ridge should maintain a theme of the flow disrupting but at the moment, this looks more likely to be to our east re snow potential although we look likely to be under the trough so cold rain? Perhaps think of week 2 jan but bit cooler. Cold zonal. remembering that this is the 'envelope' , that allows for both the Azores ridge to come east into Europe or for the trough to disrupt further west, pulling us into the more wintry zone.

[matty lfc]

You've all just read from a professional meteorologist that the meto,with all their amazing technology,are really struggling beyond 2-3 days and yet people are STILL posting charts 7,8,9 days away saying "return to westerlies now set in stone"

[kev238]

It is a really intriguing outlook. It seems certain it will stay cold until Friday of next week but how that translates to conditions on ground regarding snowfall is difficult to gauge. In my opinion there doesn't seem to be the precipitation signal for widespread disruptive snowfall- some lighter snowfall perhaps but the trough disruption looks like a weak and weakening feature at least in the first half of the week.

[Jason M]

IDO commented on the GEM control. It's worth just adding to that to say it's strongly representative of the GEM ensemble suite at day 5. In fairness the gem ens were holding the line through yesterday re a slack easterly whereas the GEFS were all over the place.

Edited January 17, 2015 by Jason M

[IDO]

Good news on the GFS 06z op up to T84, no wild swings, a general consensus with the 0z with subtle variations, one being a very slight shift west: