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Model Output Discussion - The final stretch to Christmas


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Posted
  • Location: Castle Black, the Wall, the North
  • Weather Preferences: Spanish Plumes, Blizzards, Severe Frosts :-)
  • Location: Castle Black, the Wall, the North

    I agree Nick but I would be more concerned if the jet looked like aligning sw / ne with a persistent long draw mild feed and I don't see any evidence of that occurring so at least we will continue to see cold incursions with wintry showers and night frosts until a major wintry spell develops and I think we will have a major wintry outbreak before this winter is over

    Edited by Frosty.
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    Mean while in the real world away from the MOD... A tragic accident has cost 6 lives in Glasgow. yes this is off topic but a timely reminder of just how unimportant the weather really is in our lives.

    There is an enormous lack of respect for other people in this thread at the moment. I suggest that if one doesn't have something to add to the model discussion with a salient chart or pertinent inf

    Model uncertainty throwing both operational and ensemble data into discontinuity has proved as rife as was expected a week ago - when AAM flipped to negative tendency along with GWO phasing that was i

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    Posted
  • Location: West Midlands
  • Location: West Midlands

    I agree Nick but I would be more concerned if the jet looked like aligning sw / ne with a persistent long draw mild feed and I don't see any evidence of that occurring so at least we will continue to see cold incursions with wintry showers and night frosts until a major wintry spell develops and I think we will have a major wintry outbreak before this winter is over

     

     

    Yes any sw'ly flow doesn't look too mild with plenty of cold PM air to tap into to our West/Northwest, this is winter in the UK.

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    Posted
  • Location: Reigate Hill
  • Weather Preferences: Anything
  • Location: Reigate Hill

    No change from the ECM op at D10, except the Arctic High no longer modelled (predictable) with WAA firing up the Pacific Ridge. Probably overdoing that as usual:

     

     post-14819-0-56802500-1419665271_thumb.g

     

    GEM at D10 undercuts the Pacific Ridge allowing the PV lobe over Canada to discharge east and west so this allows more heights to our south and the Atlantic remains more N. UK:

     

    post-14819-0-34618200-1419665434_thumb.p

     

    The GEM to an extent ties in with how the GFS is now modelling the Pacific Ridge with the WAA not as strong allowing it to become messy with lower heights sliding from east and west:

     

    Op & P: post-14819-0-63665800-1419665707_thumb.ppost-14819-0-18990000-1419665708_thumb.p

     

    That looks like a signal for the Pacific HL wedge to move and the GEFS at D12 are all over the place as to how it develops. Not much use to our sector till late in FI when 3-4 members show possibilities of a change but still nothing blocked or cold. The D16 mean is a fair representative of the poor NH profile for the UK at D16:

     

    post-14819-0-60237800-1419666010_thumb.p

     

    The other side of the NH is where the interest remains. It is very good that the PV remains relatively disorganised (to varying degrees) but not good that it still remains dominant over to our NW.

     

    No snow down here due to the warm sector but howling wind for several hours. Should be dry in the SE till Friday but turning more unsettled the further NW you are Thursday. Temps look to be 4c down to overnight -2c in the London area but nearer average by next weekend. 

    Edited by i'm dreaming of...
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    Posted
  • Location: HILL OF TARA IRELAND
  • Weather Preferences: SNOW ICE
  • Location: HILL OF TARA IRELAND

    No change from the ECM op at D10: attachicon.gifECH1-240 (3).gif

    GEM at D10 undercuts the Pacific Ridge allowing the PV lobe over Canada to discharge east and west so this allows more heights to our south and the Atlantic remains more N. UK:

    attachicon.gifgemnh-0-240 (1).png

    The GEM to an extent ties in with how the GFS is now modelling the Pacific Ridge with the WAA not as strong allowing it to become messy with lower heights sliding from east and west:

    Op & P: attachicon.gifgfsnh-0-192 (2).pngattachicon.gifgfsnh-0-192 (1).png

    That looks like a signal for the Pacific HL wedge to move and the GEFS at D12 are all over the place as to how it develops. Not much use to our sector till late in FI when 3-4 members show possibilities of a change but still nothing blocked or cold. The D16 mean is a fair representative of the poor NH profile for the UK at D16:

    attachicon.gifgensnh-21-1-384 (3).png

    The other side of the NH is where the interest remains. It is very good that the PV remains relatively disorganised (to varying degrees) but not good that it still remains dominant over to our NW.

    No snow down here due to the warm sector but howling wind for several hours. Should be dry in the SE till Friday but turning more unsettled the further NW you are Thursday. Temps look to be 4c down to overnight -2c in the London area but nearer average by next weekend.

    You forget to mention at 192hrs the ecm has -8uppers approaching from the west that's not mild as polar air sinks further south,and if ukmo went out that far I would say by its 144 chart it's going that way to,so for me a big improvement this am.

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    Posted
  • Location: Reigate Hill
  • Weather Preferences: Anything
  • Location: Reigate Hill

     

    You forget to mention at 192hrs the ecm has -8uppers approaching from the west that's not mild as polar air sinks further south,and if ukmo went out that far I would say by its 144 chart it's going that way to,so for me a big improvement this am.

     

    Yes the GFS has 3 PM incursions during D7-16. With the flow originating from the NW it is taken that there will be potential for the W/NW coasts for wintry showers. However more sustained blocking is needed for substantial UK wide snow. 

    Edited by Osbourne One-Nil
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    Posted
  • Location: Cork, Ireland.
  • Weather Preferences: Storms frost snow heatwaves
  • Location: Cork, Ireland.

    No change from the ECM op at D10: attachicon.gifECH1-240 (3).gif

     

    GEM at D10 undercuts the Pacific Ridge allowing the PV lobe over Canada to discharge east and west so this allows more heights to our south and the Atlantic remains more N. UK:

     

    attachicon.gifgemnh-0-240 (1).png

     

    The GEM to an extent ties in with how the GFS is now modelling the Pacific Ridge with the WAA not as strong allowing it to become messy with lower heights sliding from east and west:

     

    Op & P: attachicon.gifgfsnh-0-192 (2).pngattachicon.gifgfsnh-0-192 (1).png

     

    That looks like a signal for the Pacific HL wedge to move and the GEFS at D12 are all over the place as to how it develops. Not much use to our sector till late in FI when 3-4 members show possibilities of a change but still nothing blocked or cold. The D16 mean is a fair representative of the poor NH profile for the UK at D16:

     

    attachicon.gifgensnh-21-1-384 (3).png

     

    The other side of the NH is where the interest remains. It is very good that the PV remains relatively disorganised (to varying degrees) but not good that it still remains dominant over to our NW.

     

    No snow down here due to the warm sector but howling wind for several hours. Should be dry in the SE till Friday but turning more unsettled the further NW you are Thursday. Temps look to be 4c down to overnight -2c in the London area but nearer average by next weekend.

    Certainly looks to me IDO that things will become quite zonal as we head into week 2. As you rightly point out, pv to our northwest very evident indeed, albeit somewhat disorganised. At least with seemingly lower heights to our south by then, no fear of Uncle Barty paying us a visit.

    PM incursions aplenty  :yahoo:

    post-17830-0-19567800-1419668102_thumb.j

    post-17830-0-67004500-1419668115_thumb.j

    post-17830-0-31334500-1419668133_thumb.j

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    Posted
  • Location: Stoke Gifford, Bristol
  • Location: Stoke Gifford, Bristol

    It will be a damp squib of a Winter if PM incursions from the NW is the best we can get especially for the S/SE/E/SW.

    Absolutely.

    Our old friend the Azores High seems to be influential at times; indirectly at least.

     

    Edited by Osbourne One-Nil
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    Posted
  • Location: Reigate, Surrey 78m asl
  • Location: Reigate, Surrey 78m asl

    Looking at the GFS temperatures (I know they are not entirely accurate but it's ehat I've got!) over the next week, it's not warm - top temps in the London area:

    3c, 3c, 3c, 3c, 4c, 4c, 5c...

    Not perishing, but certainly not mild by any stretch... It will be interesting to see where this will lead, I don't see much mild on the charts, but after this week, it looks a little damp for us down south, but the further north you are with elevation, you could hit the jackpot if these pm shots come off :)

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    Posted
  • Location: st albans
  • Location: st albans

    Could be some very windy conditions on offer week 2 if we get runners in the base of the upper trough.

    I wouldn't be predicting what may be delivered by that general set up other than wind and rain. (Did I just make a prediction?)

    Anyway, I suspect heights and uppers low enough at times in the northern half of the uk for some wintry conditions. (More than just wintry showers)

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    Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks

    Yes agree with that ba, the anomaly charts all 3 I use show a strong w'ly from America over the Atlantic into the UK, Trough conditions for the northern half, less so for the far south. Some differences between the 3 in how things look east of the UK, but overall unsettled looks the theme for the northern half and some fairly deep surface features could occur, how far south these may affect is certainly not clear on the anomaly charts, even less so to me than usual. Whether a smaller upper trough within the main trough-ridge set up may at some point change the main pattern is also not possible to say, it might happen but that is about all the guidance on that possible at this stage.

    Cold for a while as the upper ridge and surface high take time to move. I doubt anyone on here is going to be closer to what occurs over the UK than the present 6-30 day Met O outlook. Obviously it will change in detail as, perhaps the minor upper troughs in the main system I mention above, create short term day to day emphasis.

    There is as yet no signal I can see looking at various outputs that is a strong enough indicator to change from what the above paragraphs suggest. That is not to say they will not change they almost certainly will, but in what way I have no idea if I am totally honest.

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    Posted
  • Location: Reigate Hill
  • Weather Preferences: Anything
  • Location: Reigate Hill

    Could be some very windy conditions on offer week 2 if we get runners in the base of the upper trough.

    I wouldn't be predicting what may be delivered by that general set up other than wind and rain. (Did I just make a prediction?)

    Anyway, I suspect heights and uppers low enough at times in the northern half of the uk for some wintry conditions. (More than just wintry showers)

    Certainly wouldn't rule out frontal snow or short wave features but this far out you won't get me hyping up that potential. The same applies to elevation in the north, a greater chance of a dump. As last night showed predicting snow is rather difficult even hours beforehand! Anyway IMBY my excitement is rather muted.

    CFS in Jan remains rather uninspiring but Feb is back on course with HLB and a cold outlook. We are again relying on a SSW for widespread cold. The GFS strat at 10hpa are polar opposites at D10 so any bodies guess as to how that potential warming event will downwell to the trop?

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    Posted
  • Location: Raynes Park, London SW20
  • Location: Raynes Park, London SW20

    Yes agree with that ba, the anomaly charts all 3 I use show a strong w'ly from America over the Atlantic into the UK, Trough conditions for the northern half, less so for the far south. Some differences between the 3 in how things look east of the UK, but overall unsettled looks the theme for the northern half and some fairly deep surface features could occur, how far south these may affect is certainly not clear on the anomaly charts, even less so to me than usual. Whether a smaller upper trough within the main trough-ridge set up may at some point change the main pattern is also not possible to say, it might happen but that is about all the guidance on that possible at this stage.

    Cold for a while as the upper ridge and surface high take time to move. I doubt anyone on here is going to be closer to what occurs over the UK than the present 6-30 day Met O outlook. Obviously it will change in detail as, perhaps the minor upper troughs in the main system I mention above, create short term day to day emphasis.

    There is as yet no signal I can see looking at various outputs that is a strong enough indicator to change from what the above paragraphs suggest. That is not to say they will not change they almost certainly will, but in what way I have no idea if I am totally honest.

    Yes John - after the high is pushed away, a very zonal outlook. No sign of any deep cold at all - all rather disappointing. Of course, the outputs can change but for now Atlantic and zonal looks the form horse in the medium term.

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    Posted
  • Location: Catchgate, Durham,705ft asl
  • Location: Catchgate, Durham,705ft asl

    A decent split in the PV at 192 hrs shown on the 00z NAEFS this morning,with those arctic heights forcing it apart.

     

    Could we about to see the AO tanking negative.?

     

     

     

     

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    Posted
  • Location: Midlothian
  • Location: Midlothian

    A striking feature of the Gfs 00z op run this morning is a distinct lack of anything truly mild, temperatures are generally below average throughout the run and decidedly on the cold side for the next five days or so. It's very noticeable how the atlantic fires up during early January but with a more southerly tracking jet, this run shows cold and stormy conditions at times through low res with a risk of wintry precipitation, however, from now until the middle of next week shows high pressure becoming centred across the south of the uk with lots of frosty conditions and an increasing risk of freezing fog, for the north west it shows a gradual transition to more unsettled, windier and less cold weather but with pm incursions later next week. So...going forward, it looks like a wintry flavour to our weather for the next few weeks in one form or another.

     

     

    PS..sorry about the chart sequence being back to front, I promise I did put them in the right order on my pc.  :smiliz19:

    I cant see it Frosty. I mean its hard to pinpoint exact temperatures obviously, but i think after the next 4/5 days things really do get milder. Very long drawn south westerlies Its been more than hinted at by the models.

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    Posted
  • Location: Castle Black, the Wall, the North
  • Weather Preferences: Spanish Plumes, Blizzards, Severe Frosts :-)
  • Location: Castle Black, the Wall, the North

    I cant see it Frosty. I mean its hard to pinpoint exact temperatures obviously, but i think after the next 4/5 days things really do get milder. Very long drawn south westerlies Its been more than hinted at by the models.

    Well. we all see things differently thankfully or the world would be a very boring place, however, unusually for me, I posted charts to back up my earlier post and really struggled to find anything mild apart from fleeting incursions through low res. What I did see was a lot of cold anticyclonic weather until later next week further SE and further ahead, a lot of polar maritimes incursion and a cranking up atlantic with more energy pumping into the southern arm of the jet with occasional bouts of cold, stormy and wintry weather, especially but not exclusively further north.

    Edited by Frosty.
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    Posted
  • Location: Murrayfield, Edinburgh
  • Location: Murrayfield, Edinburgh

    Well. we all see things differently thankfully or the world would be a very boring place, however, unusually for me, I posted charts to back up my earlier post and really struggled to find anything mild apart from fleeting incursions through low res. What I did see was a lot of cold anticyclonic weather until later next week further SE and further ahead, a lot of polar maritimes incursion and a cranking up atlantic with more energy pumping into the southern arm of the jet with occasional bouts of cold, stormy and wintry weather, especially but not exclusively further north.

    I struggle to see anything cold in the output - it looks like the Atlantic will fire up.

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    Posted
  • Location: chellaston, derby
  • Weather Preferences: The Actual Weather ..... not fantasy.
  • Location: chellaston, derby

    . With a whole week of cold and frosts ahead we have had it good so far....

     

     

    really?.... its looking to me that by wednesday itll be far more average and with an increasing southwesterly and cloud temps will prevent frosts by weds night, and fridays looking wet, windy, but mild. (ok thats the only milder shot in the outputs it must be said)

     

    I think coldies will be not too unhappy because polar maritime incursions look likely beyond the cold,frosty settled spell which will hold on until well into next week the further south east you are. So we are likely to see further wintry conditions at times.

     

    absolutely karl.... as ido also mentions theres several pm incursions in this mornings runs. it looks like becoming unsettled later this week and beyond, but its average - cold with no mildness currently expected. (except possibly milder on friday). smacks of early 1984 to me, alot of cold zonal with some heavy snowshowers at times (but im prone to cheshire gap streamers when the winds in the northwest).

     

    as for 'temperaturegate' from yesterday (gfs vs tv) i note the tv broacasts this morning have not backed down from their expected daily maxs . tbh i wouldnt expect them too, but already my bit of snow is starting to melt, so a gradual thaw will start today (i lost about 2/3 of the snowcover overnight before the clearer cold air arrived). id suggest that the temps predicted by the met office people on bbc news will be more accurate then those posed by the gfs yesterday and were used to support 'a week of freezing temps with no thaw'. (which of course was a valied and accurate account if the gfs temp profiles verify).

    but this morning the gfs has modified its temp predictions and are now more inline with what the bbc broadcasts were expecting. so yesterdays gfs predicted 'no thaw and frost days' all next week were inaccurate.

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    Posted
  • Location: chellaston, derby
  • Weather Preferences: The Actual Weather ..... not fantasy.
  • Location: chellaston, derby

    I struggle to see anything cold in the output - it looks like the Atlantic will fire up.

     

    i dont. there are plenty of cold incursions throughout the run, and by cold i mean days below average (which isnt mild). ok theres no lasting deep cold, but view the upper air profiles and theres alot of cold pm air crossing the uk and very few milder blips.

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    Posted
  • Location: Reigate Hill
  • Weather Preferences: Anything
  • Location: Reigate Hill

    Well. we all see things differently thankfully or the world would be a very boring place, however, unusually for me, I posted charts to back up my earlier post and really struggled to find anything mild apart from fleeting incursions through low res. What I did see was a lot of cold anticyclonic weather until later next week further SE and further ahead, a lot of polar maritimes incursion and a cranking up atlantic with more energy pumping into the southern arm of the jet with occasional bouts of cold, stormy and wintry weather, especially but not exclusively further north.

     

    Yes a couple of days of TM air as the high sinks: post-14819-0-12242200-1419675635_thumb.ppost-14819-0-70649500-1419675634_thumb.p

     

    They are from the mean. From then the whole of the UK under 0c or colder uppers till D16: post-14819-0-12202200-1419675739_thumb.p

     

    So mild not really in the forecast; average or just below in the south and colder than average for the north. GFS are also firming up on the delay of the Atlantic as a small HP builds to the west at D7 and moves east:

     

    op post-14819-0-30856700-1419675941_thumb.p  P: post-14819-0-25007500-1419675987_thumb.p

     

    That is responsible for helping dragging in cold uppers from week 2: post-14819-0-92659700-1419676080_thumb.p

     

    GEM picked this up as well and ECM has hinted at it.

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    Posted
  • Location: West Midlands
  • Location: West Midlands

    A striking feature of the Gfs 00z op run this morning is a distinct lack of anything truly mild, temperatures are generally below average throughout the run and decidedly on the cold side for the next five days or so. It's very noticeable how the atlantic fires up during early January but with a more southerly tracking jet, this run shows cold and stormy conditions at times through low res with a risk of wintry precipitation, however, from now until the middle of next week shows high pressure becoming centred across the south of the uk with lots of frosty conditions and an increasing risk of freezing fog, for the north west it shows a gradual transition to more unsettled, windier and less cold weather but with pm incursions later next week. So...going forward, it looks like a wintry flavour to our weather for the next few weeks in one form or another.

     

     

    PS..sorry about the chart sequence being back to front, I promise I did put them in the right order on my pc.  :smiliz19:

     

     

     

    Great post, i can't see those phantom very long drawn southwesterlies either, no evidence of them in the model output at all.

     

    Winter in one form or another continues for the foreseeable.

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    Posted
  • Location: Peterborough
  • Weather Preferences: Snow and frost in the winter. Hot and sunny, thunderstorms in the summer.
  • Location: Peterborough

    Looks like the storm shown in six days time will be deflected north of the UK by the northern Euro high and it looks like another ridge from the Azores will build in behind it. So every chance that southern areas will stay mostly dry apart from a weak cold front pushing south east on Friday.

    We will tend to lose the sun from Wednesday onwards though it looks brief. Any warm up will be a change from 2C maxima and frosts to 4/5C and little diurnal range as the winds shift to the south west and strengthen, but these will never get particularly mild away from the north west. As the front clear we could see quite a potent PM burst with wintry showers for western coasts, but away from that a return to calm and crisp conditions as the cold front ushers away the low level cloud and restores a sunny picture to most of the UK.

    gfs-0-72.png?6

    gfs-0-144.png?6

    gfs-0-192.png?6

    Now then week 2

    There seems to be a break in the strong Atlantic jet in the wake of the deep low crossing north of us on Friday, so maybe a chance to develop something more robust to keep the Atlantic at bay and even remotely develop something much colder. A lot of this driven by heights building over Alaska.

    Edited by Captain shortwave
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    Posted
  • Location: NR LOURDES SW FRANCE
  • Location: NR LOURDES SW FRANCE

    After a rather underwhelming ECM operational output the GFS 06hrs run adds a bit more interest with the  deep low crossing the USA and engaging the PV.

     

    It's this type of interaction that might allow more sharpness and dig south of the low to the west of the UK aswell as pulling that PV further to the nw.

     

    post-1206-0-31180100-1419677771_thumb.pn

     

    We don't quite get the undercut here as the lower resolution then flattens the pattern out but if that deep low does develop then the amplitude of that will dictate what happens to the low to the west of the UK, you can see at T192hrs this developing a shortwave at the base.

     

    What you're looking for is the acuteness of the ridge in between both lows, so not some arc but more pyramid like.

     

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    Posted
  • Location: Peterborough N.Cambridgeshire
  • Location: Peterborough N.Cambridgeshire

    Weather(excuse the pun)you prefer cold or mild,its fairly bog standard winter fayre coming up from what im viewing on the models(on mobile,cant post charts).

    All the talk of Cohens theory,ssw,opi etc have not come to fruition yet and tbh im sick to death of posts saying this will happen and that will happen in 10 days or so.....,

    Until the mo mention deep cold i wont be swayed by hopecasting,just my take on things.

    Regards all.

    Certainly understand your post. Without being rude to those who produce forecasts using techniques you mention above, but I take very little notice of what is said unless I can visually see it in the model output at a sensible timeframe.

     

    I still prefer the approach of using the model output out to +192 and then using forecasting instincts from +192 to +384 to see how that period is likely to develop. Part of the fun of model watching for me is to figure out where the models are wrong in F.I because lets be honest they usually are.

     

    Going back to my previous post and the Parallel is a good example of how the output can change more favourably for cold/snow.

     

    http://www.wetterzentrale.de/pics/Rpgfs2521.gif

     

    Remember many make the mistake in assuming we need a 1050mb GH to deliver the goods but sometimes this isn't necessary. A modest rise in pressure to our N is enough and the winter of 2012/13 is a good example of this that bought many snowfalls to my location.

     

    G

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