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Potential Storm Sunday April 29th , Rainy period till May 02nd

  • 25-04-2012 4:59pm
    #1
    Registered Users Posts: 12,778 ✭✭✭✭


    Another interesting fish being progged to develop this weekend. Develops as an interaction between some tropical air mass that gets dragged up over the continent and the cool maritime airmass over Ireland.

    The combination is a large moisture ladden depression approaching from southern France and the Med. A very strange source for a system affecting Ireland.

    At the moment the system is bring progged to the south of Ireland but it remains a real threat and is forecast at just T90hrs.

    It is of particular interest as it is a very untypical type of system that has a small chance of bringing exceptional windspeeds from a easterly direction, not what we are used to.


    Here are few charts.

    #1 Illustrating the moisture in this thing south of Ireland
    Rtavn904.png

    #2 Illustrating the pressure map, showing the small tight circulation.
    Rtavn901.png

    #3 Illustrating the current forecast sustained winds
    Rtavn909.png


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Comments

  • Registered Users Posts: 2,876 ✭✭✭JanuarySnowstor


    Whilst it is certainly one to watch I couldn't see it happening as progged.
    Seems to go against the natural law of physics:D
    Worth seeing what ECM does


  • Registered Users Posts: 12,778 ✭✭✭✭ninebeanrows


    Whilst it is certainly one to watch I couldn't see it happening as progged.
    Seems to go against the natural law of physics:D
    Worth seeing what ECM does

    Sure looks a strange one! Surely a storm can't strike Cork!:D


  • Registered Users Posts: 12,778 ✭✭✭✭ninebeanrows


    ECM goes for the interesting system to experience a intensification.

    I reckon it will be a tricky one to forecast and still at T96hrs, so will be
    very interesting to follow over next 3 days.

    ECM has threat of flooding written all over it/ nevermind our consideration for wind.

    ECM1-96.GIF


  • Registered Users Posts: 2,876 ✭✭✭JanuarySnowstor


    The system opens out quickly as it moves close to Ireland.
    I'll give it tomorrow to see but in general it looks all wrong as how systems develop in this part of the world


  • Closed Accounts Posts: 4,279 ✭✭✭Su Campu


    Although it is unusual there is nothing that says it can't happen. It all depends on how the large upper trough that is now deepening towards Iberia cuts off on Friday/Saturday.

    The strong 150 knot polar jet currently over the north Atlantic feeding this trough will cause it to deepen southwards and become cut off by Saturday. At the same time the sub-tropical jet interacts this polar jet at the base of this trough over southern Iberia, and this interaction causes deepening at the surface near the Balearics. The upper cut-off process causes southeasterly flow steering flow at the cut-off zone, which drives the surface system northwards over France and swings it northwestwards towards us, where it pivots around the cut-off upper low.

    2012042700_38.gif

    Incindentally, this upper low meanders around northern Iberia next week and could lead to thundery events to our south in the unstable easterly flow. The south could see some action if all goes to plan.

    2012050118_1.gif

    2012050118_27.gif


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  • Closed Accounts Posts: 1,463 ✭✭✭Mr Cumulonimbus


    18Z GFS not bringing the low as far north as the 12Z run did. Might be a nice day on Sunday yet.......

    202292.png


  • Registered Users Posts: 6,827 ✭✭✭pauldry


    yeah we might even get an April high to rival 14.9c!!!!!!


  • Registered Users Posts: 763 ✭✭✭alfa beta


    pauldry wrote: »
    yeah we might even get an April high to rival 14.9c!!!!!!

    is that the highest april has managed so far?


  • Registered Users Posts: 14,268 ✭✭✭✭M.T. Cranium


    At the present time, whatever outcome you would like is there for the taking on one model or another. The most rain and wind available on 00z model runs is on the GEM. The UKMO is somewhat more subdued, the GFS has shifted south for a likely miss, and the ECM wants to take a weaker version of the system more north at first into Britain. The GME ends at 72h and looks headed for Ireland with a rather strong system.

    I think we'll have to admit that there is no clarity in this situation but as a betting man (just collected on that Barcelona-Chelsea tie and some overtime hockey) I would say ECM. The others involve too much retrogression and in most cases cyclonic curvature that doesn't seem to follow the previous event (the departing storm). So the most likely outcome would be low cloud and drizzly light rain. Everything else is still on the table.


  • Registered Users Posts: 12,778 ✭✭✭✭ninebeanrows


    6z leans things a little further north.

    It's track is very much unknown at this point.

    Rtavn781.png


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  • Registered Users Posts: 5,068 ✭✭✭Iancar29


    Just goes to show the difference the jump north can have.


    00z for 3pm Sunday
    202334.png

    06z for 3pm Sunday
    202335.png


  • Closed Accounts Posts: 1,463 ✭✭✭Mr Cumulonimbus


    Compact looking system for Sunday on the 12z run.

    202380.png


  • Registered Users Posts: 1,789 ✭✭✭BEASTERLY


    Looks interesting, oh the havoc this could have caused in January.


  • Closed Accounts Posts: 1,463 ✭✭✭Mr Cumulonimbus


    12h UKMO has the system fairly near to Iberia on Sunday.

    202385.gif


  • Registered Users Posts: 14,268 ✭✭✭✭M.T. Cranium


    I was looking at the met-E forecast for the weekend and was puzzled by the forecast for widespread heavy showers on Saturday -- can't find any guidance showing this (except for the wind direction). Could see this if wording was isolated and light showers. As to Sunday, so far GFS looks somewhat weaker than a day ago but would give 5-15 mms rain on Sunday, GEM has backed off slightly from 00z run to 12z but looks more like 10-20 mms potential. Awaiting version of ECM available to mere mortals. Don't really have mega-confidence in any low that comes out of France, they often move further east than models depict, or stay underdeveloped. Problem is that retrograde signal is often underestimated then suddenly you have the ridge clamped down, so we will no doubt be revising estimates on this for a day or two yet.


  • Closed Accounts Posts: 2,693 ✭✭✭Redsunset




    Met Office not sure of low track,


  • Closed Accounts Posts: 2,693 ✭✭✭Redsunset


    Latest ECM track
    [IMG][/img]ECM1-72_wwv3.GIF

    Making bee line for Ireland but low filing as she does, so at the moment still uncertain but most likely not that windy with some rain

    [IMG][/img]ECM1-96_lmn4.GIF


  • Registered Users Posts: 14,268 ✭✭✭✭M.T. Cranium


    This Sunday rain is about as certain as two Spanish teams in the Champions League final (as seen from Monday). It looks like a sure thing today.

    However, there is a bit of emerging consensus now, every major model has something moving towards the northwest then west.

    Still don't see where Saturday gets widespread showers, perhaps I shall not be so ignorant by midnight when I return from an adventure of my own making here.


  • Registered Users Posts: 2,876 ✭✭✭JanuarySnowstor


    Uk Met office making more of this than I would have thought
    Also ECM gives us a direct hit though it weakens quickly
    Could be some thundery potential too


  • Closed Accounts Posts: 1,463 ✭✭✭Mr Cumulonimbus


    18z GFS for Sunday. Forecast on RTE1 at 9.30pm advised of a risk of rain in the east and southeast sometime later Sunday but weren't certain for now.

    202471.png


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  • Closed Accounts Posts: 2,693 ✭✭✭Redsunset


    Here's a view of different suggested scenarios for Sunday from the main models.

    202479.JPG


  • Closed Accounts Posts: 2,693 ✭✭✭Redsunset


    Uk Met office making more of this than I would have thought

    From met office web site,
    An intense area of low pressure is forecast to approach the south of England on Saturday night and Sunday bringing up to 50mm of rain and winds gusting in excess of 50mph in exposed areas.


    That is what there concerned about, depending on actual track of course.


  • Closed Accounts Posts: 1,463 ✭✭✭Mr Cumulonimbus


    0h UKMO run. Faxes for midday Sunday and midnight Sun/Mon. 0755am forecast this morning on RTE Radio 1 calling for a dry start on Sunday morning, rain later into the east.

    202496.gif

    202497.gif


  • Registered Users Posts: 6 Broken Loose


    I was looking at the met-E forecast for the weekend and was puzzled by the forecast for widespread heavy showers on Saturday -- can't find any guidance showing this (except for the wind direction). Could see this if wording was isolated and light showers.

    It's less you not seeing something and more met being a little trigger happy since they got caught by the "Bray Tornado" when they predicted a dry start to that morning in the east. Anything easterly and with a possible sea effect means they have to predict it just in case it does happen (Though the "Bray Tornado" was a case of a really unstable atmosphere, a sea effect streamer and some rapidly developing shear that developed quickly and disappeared just as quick.) Met E always does this when they get caught by something and over cooks it a lot just in case until the day in question when the models become clearer whenever they have been caught out. Not that I blame them since the papers and people do be all over them when they get it wrong so it's understandable that they would cover their butts just in case it happened again.

    Today they have downgraded tomorrow's forecast significantly to showers with "the odd heavy one" anyway. So it's not you missing something.


  • Closed Accounts Posts: 1,463 ✭✭✭Mr Cumulonimbus


    6Z GFS. Rain moving into eastern areas Sunday afternoon.

    202500.png

    202501.png


  • Closed Accounts Posts: 2,693 ✭✭✭Redsunset


    120427_0000_66.png


  • Registered Users Posts: 2,855 ✭✭✭Nabber


    ukprec.png


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


    So the most likely outcome would be low cloud and drizzly light rain.

    sad.png


  • Registered Users Posts: 14,268 ✭✭✭✭M.T. Cranium


    That's what my assistant, Juno the weather cat, said.


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


    Since we are on a roll..!

    Meeeowww..


This discussion has been closed.
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