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Model Outlook Jan 2009 --->

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  • 30-12-2008 11:56am
    #1
    Registered Users Posts: 5,033 ✭✭✭


    This thread is only for models and ensembles only.
    No forecasts are to be produced in here.

    As with the nature of recent runs from some of the big outputs ECMWF, GFS and UKMO there has been little agreement on a setup just outside the reliable timeframe that is T+120hrs.
    None of these setups have come off.

    The first bitter weather was expected here on New years Eve/Day modeled from last week and it is not going to happen. The upgrades and downgrades happen throughout the year not just in Winter.

    The term FI or Fantasy Island, Fupping Impossible, Frequently Inconsistent is used in the last thread.
    There is >10% of these models making it into the reliable timeframe.

    As in the last thread, the mods mentioned it several times to stay on topic, this has been ignored and some posts where deleted.
    Not only will your post be deleted you will receive a one day ban from the forum and if re-occurs a one week ban.

    I will ask anyone who is posting up a chart etc to explain why that chart is significant and to post the health warning with it if in FI. There is no problem discussing that type of chart but remember the chances of this happening is very small.

    There is no problem for a thread to be started about an upcoming event but make sure it is in the reliable timeframe and not hyperbole please.


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Comments

  • Registered Users Posts: 5,033 ✭✭✭Snowbie


    LP moves down to the south of Ireland and down the North sea from 06Z next Monday 5th bringing a NE across Ireland. Ensembles not out yet.

    viewimage.pbx?type=gfs;date=20081230;time=06;ext=156;file=h850t850eu;sess=a42a6bd62fa79cfc481c39b2119218a9;

    ECM 00z not in agreement

    ecm500.144.png


  • Closed Accounts Posts: 311 ✭✭forkassed


    I was reading Steve Murrs thoughts this morning on NW this morning and what i gathered from it was how much the jet stream plays in that all elusive high getting up into Greenland.

    The chart below shows @ T+84 the jet (yellowy/red line) trying to go up the eastern seaboard of the U.S and up and over the top of Greenland.This would allow pressure to rise in Greenland.



    Rtavn8415.png






    Unfortunately for us some of the latest models at T 108 and afterwards show the southern arm of the jet stream taking most of the energy and shooting straight across the atlantic. This prevents the heights from rising in GL and is a spanner in the works for our chances of snow.





    Rtavn12615.png



    If we want cold&snow, this is important to watch for in the models over the next couple of runs, as until the models pin down the orientation of the jet we are on a knife edge.


  • Closed Accounts Posts: 3,258 ✭✭✭MUSEIST


    If we want cold&snow, this is important to watch for in the models over the next couple of runs, as until the models pin down the orientation of the jet we are on a knife edge.[/QUOTE]

    Yes and in recent runs the southern arm has looked strong and introduces the atlantic in FI, also I would tke into account the fact that the models both GFS and ECM have been all over he place and have struglled with the high pressure over the northern atlantic, a lot of ups and downs in the models to come - no real trend forming yet IMO;)


  • Registered Users Posts: 2,953 ✭✭✭JanuarySnowstor


    Is the atlantic really that bad
    Surely what we have had the last 2 weeks (i.e. nothing) is a tad boring. I doubt very much if our interest in weather was borne out of weeks like these. At least the atlantic can throw the odd storm at us or maybe even cold zonal. In Cork today it's 8C and breezy. It doesn't get much milder than that in a strong southwesterly

    Anyway let's hope the 12z cheers us all up:D


  • Registered Users Posts: 2,953 ✭✭✭JanuarySnowstor


    12Z GFS halfway out and it looks a complete mess.
    We seem to be stuck in some kind of a col yet still miss out in the deep cold to our East
    Looking more and more like the status quo continuing into next week i.e. nothing

    I think we may welcome back the atlantic with open arms by the end of all this. A very poor few weeks and burning valuable heart of winter time


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  • Registered Users Posts: 15,947 ✭✭✭✭Villain


    The latest models don't look good at all it seems the milder air from the west is going to win out rather quick.

    It will be interesting to compare the 18z tonight with last nights I think sadly though we will see huge downgrades although the Models are struggling so things could yet change


  • Closed Accounts Posts: 3,258 ✭✭✭MUSEIST


    Well 12z gfs is a disaster for snow. It all seems to be going wrong now .What happend to those great charts of a few days ago and the general trend of greenland highs. Anyway if the ecm is similar to 12z then its the nail in the coffin i'm afraid:mad:


  • Registered Users Posts: 5,565 ✭✭✭Pangea


    hmm no one really posting any info here today.


  • Registered Users Posts: 15,947 ✭✭✭✭Villain


    The models are all over the place and no-one likes downgrades!


  • Registered Users Posts: 5,033 ✭✭✭Snowbie


    Majority of ensembles in favour of mild.

    GFS and ECM near agreement. Near reliable timeframe and 2 more runs to change but by this time tomorrow, the cold spell could be dead. Looks to be cold and frosty but with the Atlantic about to break through.

    viewimage.pbx?type=gfs;date=20081230;time=12;ext=144;file=h850t850eu;sess=453ddcf4becceb1114102c7fcf0f0d26;

    ECM

    ecm500.120.png


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  • Registered Users Posts: 2,953 ✭✭✭JanuarySnowstor


    There never was a "proper" cold spell in Ireland
    As I earlier suggested earlier even atlantic type weather in early Jan gives maxes of 8-10
    Was 8 here in Cork last few days with no frost since before Christmas.
    I welcome the atlantic with open arms, anything better than the last 3 weeks of....................erm nothing


  • Registered Users Posts: 5,033 ✭✭✭Snowbie


    JS banned for a day for going off topic.

    JS i am getting tired of your constant whining on this forum. You seem to want attention on here as your not getting it on Netweather as per your recent post about that forum.
    Either post something relevant in this thread or just read. Your decision.


  • Closed Accounts Posts: 3,258 ✭✭✭MUSEIST


    Well at the moment it looks bad for a cold spell but I would 'nt be suprised if the 18z gave a upgrade. NOAA have been predicting height rises over greenland for early january for a while now(they have been consistent with this). The GFS and ECM can get it wrong especially in dealing with situations like this so its possible that this could upgrade.I dont want to get peoples hopes up but 18z coul d have something for us:P

    610day.03.gif

    They could be wrong but its unlikely they are completely wrong wheras you can disregard some GFS runs as some are just not plausible.


  • Registered Users Posts: 490 ✭✭Snowaddict


    Hey all,

    I haven't seen the latest outputs until now but I see that things have taken a dive in terms of the potential colder outbreak. One thing to note is that NOAA have already binned the 12Z GFS Operational run.

    However, there is a clear trend there for no real wintriness, particularly on the operational outputs. Furthermore, ECMWF run is not really that good at all.

    The model outputs have now certainly backed away from the potential wintry outbreak. The 850hPA temps ensemble mean out to the 6th looks quite good, however from a brief run through the outputs, thats the only positive that I can really see to be honest.

    Unless there are dramatic changes over the next 24 - 36 hours, the potential of any wintry outbreak may unfortunately not be realised.

    A few more outputs needed, but its a big change from what I saw on the 18Z last night.

    Regards,
    SA. :)


  • Registered Users Posts: 4,329 ✭✭✭arctictree


    OK, GFS 18z rolling out now.

    The chart for Monday 12z is still very interesting. The high has intensified over Scandinavia and pushing cold air over Ireland as the Atlantic LP moves in. This is still bordering on FI at t+138 but the building blocks of it are appearing now at t+120

    I'm keeping an eye on this as it is only a few runs away from the reliable timeframe.


  • Closed Accounts Posts: 252 ✭✭danni2


    The 18z is much better, looks like an easterly at T144


  • Registered Users Posts: 490 ✭✭Snowaddict


    This chart is usually reserved for the deep realms of FI. Now this run may be a false hope and is only one run, but the fact that these potently cold charts are appearing nearer the more reliable timeframe, its very interesting to say the least.

    I wonder where the 18Z operational will stand in terms of the ensembles?

    This still shows that the outlook at the moment is far from certain past T+96.

    GFS 18Z T+144

    h850t850eu.png

    T+150

    h850t850eu.png


    A massive health warning attached to this chart, its still at T+159 and its totally out of sync with recent ECMWF outputs. Could this be a rogue run or does this set a trend for a potent easterly? Given the recent outputs, this run should be treated with a pinch of salt. IMO, the setup will flip flop right up to T+48. One thing I will say is that Jan 5th has always been shown to be very cold on GFS ensemble runs over the past 10 days. However at the moment, I'm taking this run with a pinch of salt.

    h850t850eu.png


  • Registered Users Posts: 15,947 ✭✭✭✭Villain


    I was just about to post the same charts, the Pub run is looking good but the pub run looked good last night too, Monday looks cold http://212.100.247.145/gfsimages/gfs.20081230/18/144/h850t850eu.png


  • Registered Users Posts: 4,329 ✭✭✭arctictree


    Snowaddict wrote: »
    IMO, the setup will flip flop right up to T+48.

    TBH, I have been comparing each chart to the previous run for the last few days and they have been very consistent to t+96. After that any variation causes a massive change in subsequent charts. So, I think this is the timeframe where we can start to give a reliable forecast.


  • Registered Users Posts: 490 ✭✭Snowaddict


    arctictree wrote: »
    TBH, I have been comparing each chart to the previous run for the last few days and they have been very consistent to t+96. After that any variation causes a massive change in subsequent charts. So, I think this is the timeframe where we can start to give a reliable forecast.

    Thanks Artictree. I haven't been able to view hardly any of the outputs over recent days. In this setup, very small changes will definately make the world of difference for us. However, I fear that this may be a rogue run given the latest ECM outputs.

    Lets hope not.
    SA. :)


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  • Closed Accounts Posts: 311 ✭✭forkassed


    Promising but i would bring the reliable timeframe back to t48 with this situation as small changes in the jet upstream are causing massive variations at t72+.

    Lets hope its a trend now because all this is getting exhausting.


  • Registered Users Posts: 15,947 ✭✭✭✭Villain


    If you dare to look into FI


    Rtavn2281.png


  • Registered Users Posts: 490 ✭✭Snowaddict


    Last post from me, I will check in again as soon as possible. For comparison at the moment, here's the latest outputs from 4 models for T+144 or T+147 approx, which is still well outside of the more reliable timeframe and is subject to substantial and significant change.

    JMA


    index.php?act=attach&type=post&id=74137

    GFS Operational

    h850t850eu.png

    ECM

    ECM1-144.GIF?30-0


    UKMO

    Rukm1441.gif

    Regards,
    SA. :)


  • Registered Users Posts: 8,913 ✭✭✭Danno


    Dodgy data, unable to get a handle on the jet, retrogression, shortwaves... the models are getting some battering and don't know what way to go by the looks of it. The last two runs have been a disaster [according to posts on here - did not get to see them myself] - so what is going on folks? Do we look for something else to enlighten us on what the weather ahead is going to be?

    I just don't know what to make of it. But my gut feeling says something big is on the way [and NO it's not a big fart after all the Christmas food and beer :D ]

    I am off now to investigate tonights 18z and offer my opinions.

    Just had a quick 500hpa look out to 102hrs and the low over Denmark is still there, though I did expect this feature to be showing stronger on the runs by now...

    More in a while...


  • Closed Accounts Posts: 3,258 ✭✭✭MUSEIST


    [I just don't know what to make of it. But my gut feeling says something big is on the way [and NO it's not a big fart after all the Christmas food and beer :D ]

    Better not be!:D

    Anyway another good 18z run like 24 hrs ago it was similar and all runs in between were poor for snowlovers- models are all over the place - just dont trust them at the moment. Also interesting how on the 18z a ridge of high pressure comes into play from the azores- will be interesting to see if that trend continues in later runs.:confused:


  • Registered Users Posts: 5,565 ✭✭✭Pangea


    Snowaddict wrote: »
    Hey all,

    however, there is a clear trend there for no real wintriness, particularly on the operational outputs. Furthermore, ECMWF run is not really that good at all.

    The model outputs have now certainly backed away from the potential wintry outbreak.

    Unless there are dramatic changes over the next 24 - 36 hours, the potential of any wintry outbreak may unfortunately not be realised.


    Regards,
    Snowaddict wrote: »

    This chart is usually reserved for the deep realms of FI. Now this run may be a false hope and is only one run, but the fact that these potently cold charts are appearing nearer the more reliable timeframe, its very interesting to say the least.

    I wonder where the 18Z operational will stand in terms of the ensembles?

    This still shows that the outlook at the moment is far from certain past T+96.



    A massive health warning attached to this chart, its still at T+159 and its totally out of sync with recent ECMWF outputs. Could this be a rogue run or does this set a trend for a potent easterly? Given the recent outputs, this run should be treated with a pinch of salt. IMO, the setup will flip flop right up to T+48. One thing I will say is that Jan 5th has always been shown to be very cold on GFS ensemble runs over the past 10 days. However at the moment, I'm taking this run with a pinch of salt.
    SA. :)[/quote]

    wow what a contrast in the space of one hour from both of your posts , thats why i think all these models are a waste of time, they change constantly from highs to lows
    :(

    is this the dramatic change u hoped for?


  • Registered Users Posts: 490 ✭✭Snowaddict


    Pangea wrote: »
    SA. :)
    wow what a contrast in the space of one hour from both of your posts , thats why i think all these models are a waste of time, they change constantly from highs to lows
    :(

    is this the dramatic change u hoped for?

    Hey Pangea. I'm away at the moment so I can't keep up much with the outputs, but when I viewed the 12Z Op it was not good at all, as is the latest ECM 12Z.

    The 18Z GFS Op would be the dramatic change that would be needed, however this is one run and as I said, it really needs to be taken with a pinch of salt. From what I can breifly see, there is huge uncertainty at the moment.
    Treat all of the outputs with caution at this time. However, we need to see continuous cross model agreement at a very close timeframe before we can contemplate any change back in favour of a cold outbreak.

    I will try check in tomorrow again if possible.

    Regards,
    SA. :)


  • Posts: 0 [Deleted User]


    To be honest (yes It's me) model reading past 144 especially in complicated set ups is not meant to be forecasting,never is,never was and never will be.

    The current set up is Very complicated.I've never seen anything like it in terms of model confusion or professional forecaster cautiousness and I've been looking at this stuff I suspect since before a lot of the new posters here were born as has the likes of snowbie,Supercell and certainly mothman.

    Where are we at this point? Well leaving the rather peachy 18z aside [its a snowfest] we've got a strong signal from the UKMO forecasters tonight that this is going in the right direction..
    When you see the likes of Peter Gibbs putting up maps of the whole of Europe and hinting thats where our weather will be coming from for the foreseeable,then theres little cause for concern folks.

    We are always on the edge of anything coming from that direction so we are always looking for more intensity than our friends across the water and we are always at the risk of dipping out of the cold while they stay in etc but lets see what happens.


  • Closed Accounts Posts: 5,150 ✭✭✭Deep Easterly


    Welcome back BB!!! :D


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  • Registered Users Posts: 8,913 ✭✭✭Danno


    Welcome back BB! Hope ya had a good Christmas and that the few tipples have helped you unwind and relax!

    I agree with you about anything after T+144 (Current Time + 144 hours), but the sheer persistance of the models about this cold spell has caught everyone's attention I am sure you will agree.

    As I said earlier, we have the theme in place, now we are looking for the detail, and as you rightly pointed out, the reliability of these models to be so fine tuned in detail from such a far off time is almost impossible.

    The best thing we can do is discuss the T+144 era in the theme of things to come, but to suggest snow showers in Dublin and not in Belfast from these FI charts is a complete waste of time.

    Hope to see you online more over the winter [a REAL winter hopefully!] :D


This discussion has been closed.
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