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Model Output Discussion - 10th Jan Onwards


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

    further to the post I made above after Nick F posted (had not seen that when I posted). The 500mb charts from EC-GFS this morning are somewhat different to how the NOAA 6-10 and 8-14 portry the 500mb flow over the coming 6-14 or so days. They appear to have dropped the split 500mb flow and gone with the mobile Atlantic idea still with far north blocking. But they still keep, approximately, the 4 main trough pattern so it is hard to tell if this is some kind of different pattern developing or will the one shown by NOAA become the pattern again. So whilst the upper air is still to be decided it really is no wonder that the models that are trying to show the surface pattern chop and change as they are doing. This will continue until a more solid concesnus is arrived at for the upper air. No idea when or how that is going to occur!

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    Posted
  • Location: Wellington, NZ, about 120m ASL.
  • Location: Wellington, NZ, about 120m ASL.

    Another run which has somewhat different short term synoptics but past D8 there seems to be some quite impressive convergence:

    Posted Image

    A cracking FI, all meaningless at this range but the vortex split, Arctic high and northward ridging of the Azores to Greenland are present once more:

    Posted Image

     

    This type of thing was seen in model runs in early November too.

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

    adding yet another comment to the two I've already made!

    Look at the difference between EC and GFS in how they deal with that upper northern ridge. Not for the first time on any of the 3 anomaly charts I look at every day, this time it is GFS, that is trying to ridge down from the Arctic into Greenland. IF this was kept for 2-3 days and the other two picked it up then it might well indicate the change most on here are waiting for but not until all 3 have shown it for at least a couple of days.

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    Posted
  • Location: Wellseborne, Warwickshire
  • Weather Preferences: Southerly tracking low pressure in winter. Hot and thundery in the summer
  • Location: Wellseborne, Warwickshire

      you would think so shaun but the extended ecm ens continue to run the northern arm through the uk after a short shift south around day 10/11.

    It's all very fickle at the minute as it's so far out but one would assume with the vortex weakening , February is when the Atlantic dies of death , along with AO signature that looks like setting up , without looking at the ECM ens , the most likely scenario from that point would be for northern blocking to take hold , so not too worried at the minute about the ECM because post t144 it's been absolutely woeful , only last night was it looking like an easterly developing only to completely vanish from this mornings output, which leads me to my next point.After all the drama regarding the scandi high will it/won't it push west , I think if we were gonna stand a realistic chance of having it then we would see all models latch onto it for next wk by now , yesterday we were looking very close to snow event next wk and that's without the easterly , but now that's more or less gone this morning as the whole pattern gets shunted east , I think it's a case of the models over estimating the block once again to be honest , I really hope I'm wrong but just can't see it . But I also think we need to be looking post day 10 for a very interesting February , a negative AO with a southerly jet stream and northern blocking around Greenland into the arctic is my guess , aided originally by the significant east pacific ridge giving lots of amplification , with the Azores high playing a part ridging north a aswel. All to play for looking at feb , but this scandi high is becoming a nuisance . We may see a flip again tonight and I hope we do but can't see it .
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    Posted
  • Location: Crewe, Cheshire
  • Weather Preferences: Snow, storms and other extremes
  • Location: Crewe, Cheshire

    Control run at 216.....similar idea to the op?

     

    Posted Image

     

    EDIT: yep, very nice synoptics...

     

    Posted Image

    Edited by CreweCold
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    Posted
  • Location: Mile Oak, 3 miles West of Brighton UK, 130 Meters above sea level
  • Weather Preferences: Anything Extreme
  • Location: Mile Oak, 3 miles West of Brighton UK, 130 Meters above sea level

    IMO a Cold Feb is on the cards , I've seen enough background evidence now that leads me to the form belief we'll see a swift pattern change as we head into the beginning of next month.

     

    I believe this will come from a gradual slowing down of events upstream allowing time for High pressure over the azores to meander North and West of the UK linking up with a Greeny High. (or something similar)

     

    This then opening the door for a Northerly to set up shop temporarily and IMO we'll start to see some sliding low pressure systems rolling across the English channel underneath the block instead of running over the top and thus leading us to the holy grail of a decent North Easterly | Easterly feed.

     

    IMO the GFS 06z control and Operational is trending in the right direction and I suspect other LR models and anomally charts to start picking up on HLB soon.

     

    06z Control run

     

    Posted Image

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    Posted
  • Location: Longwell Green, near Bristol
  • Weather Preferences: Storms, Gales, frost, fog & snow
  • Location: Longwell Green, near Bristol

    Not often you see both the Op and Control run follow each other so closely right out to 384hrs;

    post-12721-0-00188400-1389960769_thumb.j

    Pretty much neck & neck all the way. Both colder solutions in the extended timeframe but irrelevant at this stage.

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    Posted
  • Location: Wellseborne, Warwickshire
  • Weather Preferences: Southerly tracking low pressure in winter. Hot and thundery in the summer
  • Location: Wellseborne, Warwickshire

    Indeed it does (albeit the EC32 postage stamps show many varied possibilites), but UKMO stress very low confidence given wide range of synoptic types showing into 10-15d period. For example, MOGREPS-15 doggedly continues a yes-no oscillation in runs of easterly patterns, with another bout of E-or-N flow now highlighted later into the 10-15d period. The level of uncertainty from Friday next week onwards is very striking. Having said that, the (extended) UKMO-GM didn't ever buy the notion of a particularly cold easterly end of next week, despite other output going for it big time (i.e. it was akin to NCEP and ditto latest EC DET which has become more muted on the idea), but given conflicting MOGREPS signals plus EC output prior to the 00z, the potential most certainly remains there and consequently the great uncertainties into next weekend are at the heart of UKMO guidance briefings. As for later into the next 10-15 days, anyone writing-off colder potential at this stage is bonkers, given the raft of possible outcomes showing across many ENS suites (and not just MOGREPS). A very difficult period for medium-range forecasters.

    Hi Ian , it sounds like it's all for grabs at the minute , so given the potential easterly , is it still by means of this scandi ridge ? Because to me background signals given the enormous east pacific amplification seems to favour a potential -NAO in the 10-15 day period , i mentioned it days ago and now certain models beginning to show the pattern change firstly in the -AO , then with ridging into greenlands been met from both sides (ie polar high meeting Azores ) of course it's very tentative at the minute but I'm convinced that's where we could be heading . So my question is do you see the scandi ridge as a big player in the 2wk period , or do you see it coming from the -AO setting up leading to possible Greenland hight rises ? Really interested to hear your thoughts Ian . Thanks
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    Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks

    Not sure what Exeter will tell Ian but I would punt, IF an upper ridge does occur sufficiently to affect the UK, for it to be from N-NW.

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    Posted
  • Location: West Sussex
  • Weather Preferences: Extreme cold & snow
  • Location: West Sussex

    Prophetic musing for February from poet William Barton

     

    February fills dikes, overflows fields
    and streams, turns paths to slippery ooze.
    Petulant winds crease the surface of the lake

     

    Wouldn't be surprised in the slightest given the way things have been and given another record cold shot into N America which will surely fire up the jet again across the Atlantic.

    The EC 32 is also doggedly zonal in the further outlook.

     

    ENS pointing the way

    Posted Image

     

    Could be heading to a record wet winter especially in the south. Posted Image

     

    METO agree more or less "Current indications point towards changeable conditions persisting into early February."

    Edited by Purga
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    Posted
  • Location: King’s Lynn, Norfolk.
  • Weather Preferences: Hot and Thundery, Cold and Snowy
  • Location: King’s Lynn, Norfolk.

    Wow, them outputs don't surprise me really. Bound to be compensated somehow from this unusual unseasonal weather!

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    Posted
  • Location: Near King's Lynn 13.68m ASL
  • Weather Preferences: Hoar Frost, Snow, Misty Autumn mornings
  • Location: Near King's Lynn 13.68m ASL

    This type of thing was seen in model runs in early November too.

     

     

    Just been through the GFS archives and while there were a few attempts to get heights into greenland and some weedy easterly efforts in the FI for runs through the 8th to 10th, there really wasn't anything of note and it was all T300+. There certainly wasn't anything resembling an Arctic high. But it's all moot, as the Arctic highs showing now are still out in la-la land at the  moment.

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    Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

    Wouldn't be surprised in the slightest given the way things have been and given another record cold shot into N America which will surely fire up the jet again across the Atlantic.

     

    The EC 32 is also doggedly zonal in the further outlook.

     

    Maybe not recording breaking but GFS 06z 8 day temperature anomlay shows another freeze heading for parts of America with temperatures 6c below normal in places

     

    Posted Image

     

    Back over in the UK and GFS 06z 8 day anomaly shows below average temperatures becoming restricted to parts NW Scotland of Northern Ireland elsewhere its above average

     

    Posted Image

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    Posted
  • Location: NR LOURDES SW FRANCE
  • Location: NR LOURDES SW FRANCE

    More FI teasers by the GFS but too far ahead to put much faith in, even with an Arctic high and dropping AO and blocking to the ne its like pulling teeth to get any cold into western Europe.

     

    The PV is really in determined mood and although the blocking to the east has the odd upper cut it doesn't land a full on knock out blow, it looks like the models have underestimated the energy pouring out of the ne USA and as we've seen that together with the flatter upstream pattern has really made things complicated in terms of getting some cold into the UK before we're old and grey.

     

    The ECM operational is worse in terms of cold possibilities than the actual mean, that keeps the Arctic high further south and has more amplification upstream towards the end of its output.

     

    There is still some room for manoeuvre with the actual trough position at T120hrs, the ECM postage stamps highlight whilst theres very good agreement on the overall pattern there are some important detail diffrences:

     

    http://www.ecmwf.int/samples/d/inspect/teasers/samplers/banner/mean_sea_level_pressure_and_temperature_at_850hpa!120!pop!od!enfo!enplot!2014011700!!/

     

    How the troughing splits and how much energy is still left to phase with low pressure moving east out of the ne USA.

     

    Unless theres some westwards corrections asap then it looks like another load of limbo with all the fun held further east, then after this it really comes down to the pattern over the USA, if its amplified sufficiently then the Arctic high might be able to finally trigger some excitement if not then likely the energy upstream will phase once again with the UK limpet troughing.

     

    In terms of the more medium term sadly we have to kick out the GEM solution as that took a lot of criticism from NCEP in the diagnostic discussion, in terms of the GFS 06hrs run that continued the daily 06hrs bias of flattening the pattern even more and being too progressive, the upstream pattern has only a little amplification but certainly more than the GFS 06hrs run, it might be flattish but certainly not that flat and is an outlier over central Canada.

     

    So then overall like a broken record its very much a stalemate for the timebeing, within that of course there are margins west/east, we can only hope we see that westwards one quickly to at least deliver a shred of excitement whilst we wait for the next upstream drama to unfold!

     

    I think I should clarify something re the pattern over the USA, although NCEP continue to play up the amplified nature this really is over the west coast with shortwaves dropping se into the eastern USA troughing, we need to see a more amplified trough towards the east and this really is the sticking point in terms of whether we'll see colder weather.

    Edited by nick sussex
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    Posted
  • Location: st albans
  • Location: st albans

     

    Maybe not recording breaking but GFS 06z 8 day temperature anomlay shows another freeze heading for parts of America with temperatures 6c below normal in places

    think it will be a awful lot colder than that over there gavin. strong signs over here that the disruption will edge further east and leave us the wrong side of any undercutting flow. always a close call and i doubt its all over anyway. the period post day 4 remains fluid and the continental draw could pop up on the next run. sw of a line liverpool to london, i'd say there is very little chance of the pendulum swinging back far enough but ne of that line, i wouldnt be drawing any conclusions just yet. the current strong trend post day 8 is for the atlantic to come storming in. convincing ? certainly looks that way but even if it does, it looks likely to dive se into the continent. then the upstream trough dictates how far west the atlantic high is drawn and whether the disruption can back west as it sinks. its all very complex around a generally agreed background pattern. not surprised to read that mogreps-15 is swinging back and forth somewhat. shannon likely still very busy!
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    Posted
  • Location: West Sussex
  • Weather Preferences: Extreme cold & snow
  • Location: West Sussex

    Just been through the GFS archives and while there were a few attempts to get heights into greenland and some weedy easterly efforts in the FI for runs through the 8th to 10th, there really wasn't anything of note and it was all T300+. There certainly wasn't anything resembling an Arctic high. But it's all moot, as the Arctic highs showing now are still out in la-la land at the  moment.

    Indeed and experience should tell us that projected eye candy in the Noddy Land of FI is worthless really particularly when 'Shannon Entropy' is at record levels.

    Most serious pro forecasters don't even bother trying beyond 4-5 days out tops so all the 'cold february' stuff is hocus pocus in reality.

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    Posted
  • Location: Stunning Shropshire
  • Weather Preferences: Snow!
  • Location: Stunning Shropshire

    Not often you see both the Op and Control run follow each other so closely right out to 384hrs;

    Posted Imageimage.jpg

    Pretty much neck & neck all the way. Both colder solutions in the extended timeframe but irrelevant at this stage.

     

    I like the chance of snow at the end of that chart - it's more than a certainty! ;)

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    Posted
  • Location: portsmouth uk
  • Weather Preferences: extremes
  • Location: portsmouth uk

    I must also stress the ao was set to plummet yesterday so there for a strong indication that the arctic heights is very much in the game of cat and mouse.

     

    as indicated by ian f and and others including myself are now looking beyond day 10!

     

    and im of the fence im more confident now than anytime this winter although feel that we do need to get the up and coming zonal onslaught out the way for there to be a more positive progression.

     

    and still now the signs are firmly still there!,

    when we start to see a reduced or even a complete retreat of this arctic high I will then go with my original thoughts of writing of feb.

     

    this is now becoming the most important period of this winter as suggested earlier.

     

    feb is the month when thing most often change and going on recent years there is no reason why this feb cant bring what we have become used to.

     

    there are some fantastic neg ao outputs here even more than yesterday reflecting what the models are suggesting with the arctic heights

    Posted Image

    absolutely everything to play for if this does transpire then we can possibly enjoy a wintry feb.

    and I hope it does because I don't want my original lrf for this winter to be right.

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    Posted
  • Location: Sheffield South Yorkshire 160M Powering the Sheffield Shield
  • Weather Preferences: Any Extreme
  • Location: Sheffield South Yorkshire 160M Powering the Sheffield Shield

    Has anyone explained to Fergieweather the netweather first rule and 2nd rules of model following?

    1st rule If there's a question over cold it will always end up being mild.

    2nd rule If there's a question mark over mild it will always end up being mild.

     

    This latest will there be an easterly or not must be the longest none event in history of model watching on netweather.

     

    I've noticed the GFS is bringing even more spring like weather in FI to Deep FI.

    Edited by The PIT
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    Posted
  • Location: West Sussex
  • Weather Preferences: Extreme cold & snow
  • Location: West Sussex

    Do you not think your above comment slightly contradicts the below? If 'eye candy' in FI is worthless due to record 'Shannon Entropy', can't the same be said for the more zonal outlook which you 'wouldn't be surprised' to see?

    I wouldn't be surprised to see a more zonal outlook simple because it's the default British climate pattern in winter and more likely than cold conditions especially when there is a great deal of uncertainty. On a probabilty basis it is more likely we will see zonal conditions than not and I'm very disinclined to be taken in by fanciful FI charts showing freezing cold even if it isn't what many people 'want' to happen.

    Edited by Purga
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