Advertisement
If you have a new account but are having problems posting or verifying your account, please email Niamh on [email protected] for help. Thanks :)
New AMA with a US police officer (he's back!). You can ask your questions here

FI Charts ( T120+ onwards) Winter 2020 **READ MOD NOTE IN FIRST POST**

  • 01-12-2020 9:33pm
    #1
    Moderators, Science, Health & Environment Moderators Posts: 15,179 Mod ✭✭✭✭ Gonzo


    Mod Note

    This thread is for posting/discussing/analyzing FI CHARTS ONLY i.e. Charts in the unreliable time frame, generally +T120 onward.

    If your post does not specifically relate to an FI chart then it doesn't belong here - Off topic posts will be moved

    Thanks



    The golden gates of winter have finally swung open with hopes and dreams of white gold. Last winter was truly abysmal with the Polar Vortex of Doom writing off winter 2019 before it even began. This winter can only be better than last winter.

    The next 2 weeks looks mildly interesting for now. It looks fairly chilly over the next 10 to 14 days and after that we may see a return to milder conditions as we head into the second half of December.

    The trend is for the NAO and AO to go negative over the next week which may allow northern blocking to be become more of an influence on our weather. This will turn the winds into the north or different variations of northerly winds from the north-west or possibly the north-east. An easterly could also develop in the next 2 weeks, something to watch out for.

    The ECM looks fairly chilly over the next 10 days but nothing too cold.

    topkarten.php?map=1&model=ecm&var=1&time=240&run=12&lid=OP&h=0&mv=0&tr=24

    The next 2 weeks also look dryer than much of November but some showers or bands of rain or sleet cannot be ruled out.

    The GFS is fairly cool over the next 2 weeks and trends milder as we head towards the middle of the month.

    show_diagrams.php?geoid=64981&model=gfs&var=201&run=12&lid=ENS&bw=1

    Hopefully we will see a few flakes over the next 2 weeks but for now it appears very marginal with snow more likely over high ground. At least things currently are much more interesting than this time last year when we had a relentless raging Atlantic.


«134567120

Comments

  • Registered Users Posts: 14,307 ✭✭✭✭ nacho libre


    According to the latest GFS the monster Russian high is not going anywhere by mid- month. The Atlantic is well and truly blocked. So no sign of a return to raging zonality, but no pronounced cold spell indicated as of yet. Still we could get something interesting further down the line. It's drastically different to last years setup.


  • Registered Users Posts: 14,307 ✭✭✭✭ nacho libre


    Well the ECM op is now showing the Atlantic returning to some extent. Usually it would be the GFS being more progressive in this scenario. It will be interesting to see if the ECM tonight sticks to it's guns, let's hope it move towards the UKMO -
    as that looks like the best for extending the cold.
    In the longer term, hopefully events in the troposphere have a significant effect on the strat. A nice Christmas present would be a SSW in late December, that way if the things fell in our favour we could get a decent cold spell by late January, perhaps a bit sooner. Although a SSW before January is not likely.


  • Registered Users Posts: 1,773 ✭✭✭ dacogawa


    10 days out but worth keeping an eye on... GFS is only dropping to 975.

    ECM1-240.GIF?04-12


  • Moderators, Science, Health & Environment Moderators Posts: 10,460 Mod ✭✭✭✭ Meteorite58


    Under the influence of LP's out to +240 hrs, looks unsettled , in general not as cold as this current spell it would seem.


    kqU5lJY.gif

    sholP3o.gif


  • Moderators, Science, Health & Environment Moderators Posts: 10,460 Mod ✭✭✭✭ Meteorite58


    dacogawa wrote: »
    10 days out but worth keeping an eye on... GFS is only dropping to 975.

    Met Eireann 'Further outlook: while it looks to get milder, current indications are for more active period of wet and windy weather at times later in the week and over the weekend'.


  • Advertisement
  • Registered Users Posts: 2,728 ✭✭✭ Rebelbrowser


    I knows its the CFS but it now shows cold weather from 18 to 25 December, with steamers up to and including Christmas day, followed by a repeat of March 2018 from Stephen's day onwards! See for example:-

    20122800_0400.gif

    Just the usual boring -14 uppers down here.....


  • Registered Users Posts: 5,617 ✭✭✭ circadian


    I knows its the CFS but it now shows cold weather from 18 to 25 December, with steamers up to and including Christmas day, followed by a repeat of March 2018 from Stephen's day onwards! See for example:-

    20122800_0400.gif

    Just the usual boring -14 uppers down here.....

    I know it's way too far out to be nailed on but It would be the 4th Centre Parcs trip we've missed this year if that's the case. However, missing it for an epic dumping of snow as opposed to the pandemic would keep the wee'uns happy.


  • Registered Users Posts: 21,810 ✭✭✭✭ Kermit.de.frog


    So long as the jet stream remains to our south we always have a chance of dragging in colder air from the east. The problem right now is that there is no real cold pool there to tap due to a persistent Russian high pressure which is driving milder air up through western Russia and eastern Europe from the eastern Med.

    gfsnh-0-24.png?12

    gfsnh-1-48.png?12

    Temperatures well above average

    gfsnh-15-48.png?12

    We need to see an ejection of cold air out of the Arctic in to this region (or at least Scandinavia) before our prospects improve.

    However there are plenty of indications in the models that low pressure from the Atlantic will struggle to break through and rather continue to slide southeast in keeping with the more southerly tracking jet.

    gfs-5-192.png?12

    So we end up with these synoptic situations.

    gfs-0-156.png?12

    Almost perfect. All we are missing is the cold air to tap. That can change super fast though. All it takes is low pressure going south through Scandinavia and maintaining high pressure to our north with that southerly tracking jet and we are in.

    I'm quite optimistic meself.


  • Registered Users Posts: 3,842 ✭✭✭ fvp4


    I, for one, am stocking up on bread and snow shovels.


  • Moderators, Science, Health & Environment Moderators Posts: 10,460 Mod ✭✭✭✭ Meteorite58


    Cant see anything of note that stands out up to +240hrs from the last couple of runs, looks milder next Sun and Monday but probably wet also and a bit windy Sun or Mon and then back to cooler weather from the W, N/W for a couple of days anyway it would seem . Meridional jet so looks like a pattern of mild - cool - mild/avg for now.


  • Advertisement
  • Registered Users Posts: 347 ✭✭ Reversal


    This would make for an interesting lead up to Christmas.

    6034073


  • Registered Users Posts: 8,405 ✭✭✭ Danno


    GFSOPEU00_372_2.png

    Whoa!


  • Registered Users Posts: 348 ✭✭ torres9kop


    Danno wrote: »
    GFSOPEU00_372_2.png

    Whoa!

    Surely we need a red warning out now!! Would that chart deliver large amounts of snow on the east coast?


  • Registered Users Posts: 58 ✭✭ lostweekend3


    torres9kop wrote: »
    Surely we need a red warning out now!! Would that chart deliver large amounts of snow on the east coast?

    In theory, yes. NE winds appear to be the best for snow on the east coast. Pity it’s so far out in FI.


  • Registered Users Posts: 14,307 ✭✭✭✭ nacho libre


    So the GFS has come around to the CFS idea. Cue the GFs on its next run showing a milder solution and a meltdown ensuing over on Netweather.
    I think we can be fairly certain the Atlantic is not going to send a conveyor belts of lows from east to west for this rest of month, but are we going to get lows stalling close to Ireland and filling eventually, or will the gates to the beast from the north east(possibly north) be flung open by the systems doing the honourable thing and facilitating heights building to the north east?


  • Registered Users Posts: 5,852 ✭✭✭ pauldry


    There is certainly a better chance than recent years and if mild weather does come there seems to be a bit of blocking going on so it will probably be short lived. If the current patterns persist the cold will only get colder. Might be an icy Christmas if not a snowy one.


  • Moderators, Science, Health & Environment Moderators Posts: 15,179 Mod ✭✭✭✭ Gonzo


    fingers crossed we get something much colder and with snow before December is over, would be great to see. The trend is for the Atlantic to be well and truly back for January and once that happens it could affect us for the rest of the winter, keeping everything crossed for the next few weeks. There is a slight possibility that the blocking could remain in place for January and if that happened we could be in for some very cold weather indeed but most likely the Atlantic will get it's way for the mid winter period.


  • Moderators, Science, Health & Environment Moderators Posts: 15,179 Mod ✭✭✭✭ Gonzo


    This mornings GFS ensembles are starting to show some very cold outliers towards the end of the run as we head into Christmas with 4 to 5 runs getting as slow as -6 to -10 uppers.

    ens_image.php?geoid=64981&var=201&run=6&date=2020-12-07&model=gfs&member=ENS&bw=1

    However there are also a lot of average to mild runs so we will need to see more of the runs fall into the freezer category over the next week to have faith in a proper cold spell around Christmas time, if it does happen it could be short lived but would be great to see.

    edit: just for fun I also looked at the ensemble GFS extended that go to January 7th and some of those get as low as -12 to -14C, so it's encouraging to see that the models are still playing around with the idea of some very cold weather into the 1st week of January. Last winter there wasn't a whiff of cold in any of the models so this winter is certainly looking a bit more encouraging.


  • Registered Users Posts: 14,307 ✭✭✭✭ nacho libre


    Gonzo wrote: »
    fingers crossed we get something much colder and with snow before December is over, would be great to see. The trend is for the Atlantic to be well and truly back for January and once that happens it could affect us for the rest of the winter, keeping everything crossed for the next few weeks. There is a slight possibility that the blocking could remain in place for January and if that happened we could be in for some very cold weather indeed but most likely the Atlantic will get it's way for the mid winter period.

    There are encouraging signs in the strat, so while the Atlantic might comes back, it might not run the show for the rest of the winter. This would reflect M.T. Cranium's thoughts for how the winter will go.


  • Registered Users Posts: 1,118 ✭✭✭ mcburns07


    That's as close as we'll get to a ramp from Gonzo!


  • Advertisement
  • Moderators, Science, Health & Environment Moderators Posts: 10,460 Mod ✭✭✭✭ Meteorite58


    ECM out to +240 hrs showing us under the influence of Atlantic Lows, no great winds apart from a few windy spells but showing some very wet days especially towards the end of the run for later next week, bit far a way to know for certain but at the moment would look like heavy rain coming up from the SW on a few occasions with flooding potential on the 12Z charts. With the rain comes some milder weather at times, no deep cold showing up but will still be coolish some days. Will see if this trends over the next few runs.


    Waeu3IZ.gif

    QK8lxfi.gif


  • Registered Users Posts: 8,405 ✭✭✭ Danno


    GFSOPEU00_384_1.png

    Most models are still going for some sort of easterly or northerly in the days just before Christmas. Cold air never too far away.


  • Moderators, Science, Health & Environment Moderators Posts: 15,179 Mod ✭✭✭✭ Gonzo


    a few more outliers are going into freezer territory for the end of this mornings GFS run as we head into Christmas giving slightly more weight towards a trend towards something very cold for last week of December.

    ens_image.php?geoid=64969&var=201&run=6&date=2020-12-08&model=gfs&member=ENS&bw=1

    Most of the runs are still on the average to mild side but more and more are trending cooler with a a few genuinely Baltic runs getting close to -10C uppers. The extended GFS shows this potential cold spell starting around December 21st and lasting till about January 2nd.

    We are along way out from reliable here, but hopefully we see continued cold trends over the next 10 days with more GFS runs and other models falling into line with something potentially very cold and hopefully snowy.

    It would be truly fantastic to get a proper winter blast during Christmas week and into early January, would make such a change from waiting till March for the cold to arrive. Not looking for a 2010 or 2018 event but something decent like February 2009 would be very welcome and not too much to ask for.


  • Registered Users Posts: 5,852 ✭✭✭ pauldry


    Certainly tending a bit colder. There have been a few milder runs though so its like 50/50 Id say. But this is 2020 so anything can happen. Also the conveyor belt of Southwesterlies is being met with more resolute blocking than last year and while some mild spells are likely in the short term they dont seem to be never ending as on most runs they are getting pushed South.

    As always a lot can change and even if the next run is a milder one on the GFS we would need to see a few in a row to dash our hopes and so far there seems to be a cold run a milder run a cold run...so lets see what the next one brings...


  • Closed Accounts Posts: 624 Humberto Salazar


    I knows its the CFS but it now shows cold weather from 18 to 25 December, with steamers up to and including Christmas day, followed by a repeat of March 2018 from Stephen's day onwards! See for example:-

    20122800_0400.gif

    Just the usual boring -14 uppers down here.....
    I really hate CFS. What purpose does it serve? Every run is different. You can't even spy a trend. CFS. Complete Faraway Sh1te.
    That said, Ecm, who I respect much more, may be picking up that much colder potential from Christmas time, with East winds. Weak signals but still a possibility to be watched.


  • Moderators, Science, Health & Environment Moderators Posts: 15,179 Mod ✭✭✭✭ Gonzo


    looking fairly chilly Christmas Eve on the latest GFS run.

    GFSOPEU12_384_1.png

    GFSOPUK12_384_5.png


  • Registered Users Posts: 14,307 ✭✭✭✭ nacho libre


    I think it's safe to say we won't have Atlantic low pressure system barreling from west to east during Christmas week. The Russian high says no to that.
    Hopefully the ECM shows something promising tonight.


  • Registered Users Posts: 2,933 ✭✭✭ PokeHerKing


    I think it's safe to say we won't have Atlantic low pressure system barreling from west to east during Christmas week. The Russian high says no to that.
    Hopefully the ECM shows something promising tonight.

    Nothing safe about predicting what weather we'll have in a fortnights time imo but I admire your optimisim!


  • Registered Users Posts: 14,307 ✭✭✭✭ nacho libre


    Nothing safe about predicting what weather we'll have in a fortnights time imo but I admire your optimisim!

    There is no guarantee as you say, but looking at the northern hemisphere profile it looks unlikely that there will be a zonal onslaught in the next two weeks. We may get systems stalling close to or over us, but with the jetstream on holidays to the south we should not have a conveyor belt of low pressure coming our way

    Cue the charts tomorrow showing the Russian High saying goodbye, and Atlantic systems lining up to cross over us!


  • Advertisement
  • Registered Users Posts: 5,852 ✭✭✭ pauldry


    Yes it's all very uncertain. There is no distinctive pattern emerging yet as with some other years. This is why I think it will be just a dry calm Christmas.

    I remember a Christmas eve like the above chart almost identical and it brought icy rain and hail to Sligo and Castlebar and the paths were very slippy that morning going to mass.


This discussion has been closed.
Advertisement