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Feb 29th - Snowfall/Wintry Conditions

  • 22-02-2020 12:00am
    #1
    Registered Users Posts: 21,787 ✭✭✭✭ Kermit.de.frog


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    During Sunday afternoon and evening rain will sweep across the country from the west turning to snow as it encounters cold embedded air across Connaught, Ulster and north Leinster. There is broad agreement across all the models regarding risk.

    The snow across north Leinster and south Connaught is likely to be short lived and turn back to rain reasonably quickly but across Ulster and north Connaught some disruptive falls should be expected. Any where between 5 and 15 cms to low levels there.

    This forecast can still change to bring more of the country in to the disruptive criteria. For now it's the safest bet on north Connaught and Ulster having the disruptive weather.

    Cold start to Sunday evening but turning milder from the south. Remaining very cold through the night across north Connaught and Ulster.

    Flood risk

    25 - 35mm of rain expected overnight - together with melting snow and a full water table bringing risk of flooding particularly in the midlands and west and around Shannon river basins in particular.


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Comments

  • Registered Users Posts: 5,847 ✭✭✭ pauldry


    I'll buy the ski gear tomorrow...and bread


  • Registered Users Posts: 5,423 ✭✭✭ Berties_Horse


    And that snow will have the longevity of a fart in the wind, unless it meets the top 100m of Errigal or Croagh Patrick. Strictly in isolation.


  • Registered Users Posts: 2,416 ✭✭✭ sideswipe


    Ulster says snow.

    There’ll be a poster along in due course to say it’s snowing somewhere in Ulster, exact location unknown:)


  • Registered Users Posts: 21,787 ✭✭✭✭ Kermit.de.frog


    I have to repeat though the exact positioning of this is not certain just yet and everything depends on the track.

    Some models have it tracking a bit further south across the country which would bring a higher risk for other areas. So there is a bit of rope to work with with this.

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    Height of 0c isotherm (in meters)

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  • Registered Users Posts: 5,847 ✭✭✭ pauldry


    Weather does look indeed quite weathery next week


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  • Registered Users Posts: 21,787 ✭✭✭✭ Kermit.de.frog


    Hirlam, an important model for us, kicking the action off further south

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    Hirlam normally reasonably good at this range vs other lower resolution models.


  • Registered Users Posts: 30,402 ✭✭✭✭ Graces7


    Ready for anything out here. Extra stocks came in this week...All I need to do is bring in more turf from the North Face... and make sure the shovel is in the house in case I have to dig the cats in/out.


  • Registered Users Posts: 21,787 ✭✭✭✭ Kermit.de.frog


    ICON now goes south route as well. Change of title may be coming.

    iconeu_uk1-1-42-0.png?22-10

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  • Registered Users Posts: 21,787 ✭✭✭✭ Kermit.de.frog


    hirlamuk-42-46-0.png?22-11

    Exciting eh?

    On the edge.

    I love it.


  • Moderators, Science, Health & Environment Moderators Posts: 10,450 Mod ✭✭✭✭ Meteorite58


    ECM and ICON quite similar now, heavy snow falls the further North and both showing considerable amount of snow lying early morning. Tough driving conditions Sunday night into Monday morning in the Northern half of the country


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    Must be noted a lot of rainfall also Sunday into Monday, and what falls frozen melts so topping up the totals big time.

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


    Just waiting for Gaoth Laidir to come along and downplay the snow risk:D

    It does look promising though with some of the usually more sober short term models on board. It would be great to look out the window and see the ground covered in white rather than being rain soaked for a change!


  • Registered Users Posts: 21,787 ✭✭✭✭ Kermit.de.frog


    ...


  • Registered Users Posts: 353 ✭✭ YanSno


    Don't forget the onshore winds along the East Coast where temps will be around 4-6c. Similar setup like last year, further inland could be a different story but for now i don't see anything more than sleet for the Dublin surrounding regions.


  • Registered Users Posts: 8,191 ✭✭✭ Gaoth Laidir


    Tasty!

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  • Registered Users Posts: 2,023 ✭✭✭ Donegal Storm


    Been a while since we had a good frontal snow event, had one here in February 2011 that dumped 5-10cm in just a couple of hours. Was a horrible slushy mess the next day but I'd still take that over another day of rain


  • Registered Users Posts: 1,271 ✭✭✭ jArgHA


    Can everyone in Cork start rowing at the coast please, we can turn Ireland upside down for a few days.


  • Registered Users Posts: 8,191 ✭✭✭ Gaoth Laidir


    It does look like snow is likely for a narrow window of a couple of hours late tomorrow night alright. Soundings are just about right. Even the Arpege is on board, and it usually has a warm bias. Below is for somewhere in Leitrim at midnight, the time of the precip chart shown. Given the warm but still sub-zero saturated uppers, thickness values will be much higher (541 dam in that sounding) than normally associated with snow. This is why a sounding tells a lot more information than any map can.

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  • Registered Users Posts: 30,402 ✭✭✭✭ Graces7


    Heyl you are serious? Thought you were joking ,,,WOW!But we tend to miss out out here.. hope springs eternal!


  • Moderators, Science, Health & Environment Moderators Posts: 15,171 Mod ✭✭✭✭ Gonzo


    looks like rain for much of Dublin and Meath, hope I'm wrong, would love to see some snow from this on Monday morning, but that warm sector brings a major and sudden increase in temperatures. Looks decent for the northern 40% of the country. Hopefully the models will shift the cold further south on later runs.


  • Moderators, Science, Health & Environment Moderators Posts: 15,171 Mod ✭✭✭✭ Gonzo


    Arpege has a brief moment of snow over Dublin and Meath between 1 and 2am, probably no more than 20 to 30 minutes, then a quick transition to rain. Ulster and Donegal could see several hours of snow before turning to rain eventually.

    arpegeuk-1-42-0.png?22-12

    Hirlam offers a better chance of seeing proper snow over Meath and Dublin, several hours of it and possibly some very heavy falls in places before turning to rain.

    starts off as rain at 2am
    hirlamuk-1-43-0.png?22-11

    Widespread heavy snow around 4am between Dublin and the midlands
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    Some very heavy snow around 5am Sunday in Meath but the mild air not far behind turning everything back to rain.

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    Snow turning to rain by 6am
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    Fingers crossed the Hirlam is correct and brings the mild air in slower. If this was to upgrade with a longer transition period to rain there could be tricky driving conditions early Monday morning.

    GFS not really going for it, keeping the snow further north mainly across NI and the north-west.

    42-574UK.GIF?22-6

    Euro 4 for what it's worth is similiar to the Arpege
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  • Moderators, Science, Health & Environment Moderators Posts: 10,450 Mod ✭✭✭✭ Meteorite58


    Even though milder mid level air will have increased Monday morning there could be enough snow lying to last into the morning making for difficult conditions with the increasing winds form the LP set to track off the N coasts.


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  • Registered Users Posts: 6,440 ✭✭✭ pad199207


    Status Yellow - Rainfall warning for Connacht, Cavan, Monaghan, Donegal, Longford, Louth, Offaly, Westmeath, Meath, Clare and Tipperary

    Rain on Sunday night into Monday morning will lead to accumulations of between 20 to 25mm quite widely, with higher totals possible in upland areas.
    The rain is likely to be preceded by a period of snow in parts of Connacht, Ulster and north Leinster, before turning to rain later in the night.
    As the ground is saturated at the moment and river levels are elevated the combined effect of rainfall and snow melt may lead to some localised surface and river flooding.

    Valid: 20:00 Sunday 23/02/2020 to 08:00 Monday 24/02/2020

    Issued: 12:00 Saturday 22/02/2020


  • Moderators, Science, Health & Environment Moderators Posts: 15,171 Mod ✭✭✭✭ Gonzo


    Arpege latest update keeps the cold for slightly longer and moves the snow risk further south by about 40 miles. Still a snow to rain event.

    arpegeuk-1-37-0.png?22-17

    Hirlam moves it futher south too with several hours of potentially heavy sleet/snow across much of the country including Dublin, Wicklow, Meath, Kildare, midlands before turning back to rain Monday morning. Could be a messy Monday morning cummute for many if this pans out.

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    For NI this looks like a proper snow event with snow falling well into Monday morning and finally turning to rain as it clears during the afternoon. Could all fall as snow in parts of the north, especially over high ground.

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    Icon is similar to the earlier runs, keeping the snow more towards the far north of Leinster, Ulster and the north-west.

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    GFS is similar, keeping it mostly to the north.
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    fingers crossed the Hirlam proves most accurate.


  • Moderators, Science, Health & Environment Moderators Posts: 15,171 Mod ✭✭✭✭ Gonzo


    Hirlam also keeps it colder for longer.

    Temperatures not much above freezing at 7am.

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    very mild by lunchtime with a huge temperature contrast, up to 12C in the south and barely above freezing in the north.

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  • Registered Users Posts: 5,847 ✭✭✭ pauldry


    For me this looks a likely scenario. Lying snow in the North Monday morning. Could be school closures in the Northwest.

    Thank God the DW is off work.


  • Moderators, Science, Health & Environment Moderators Posts: 10,450 Mod ✭✭✭✭ Meteorite58


    So latest charts across the different models showing the LP frontal system arrive much earlier than previous runs and the Low center not as deep either, and a bit slower moving also with probably more precipitation falling . Winds also not as strong now for Monday, more like gusting 80 to 90km/h on the coasts and around 70 to 80 km/h overland . Big change really in such a short space of time.

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  • Registered Users Posts: 8,191 ✭✭✭ Gaoth Laidir


    A massive U-turn in the UKMO Fax forecast for 12Z on Monday. Today's 12Z forecast has the low 24 hPa higher then than the 00Z forecast had it. Amazing change in thinking just 12 hours apart.

    12Z forecast.


    ukmo_nat_fax_2020022212_048.png

    00Z forecast.

    ukmo_nat_fax_2020022200_060.png


  • Moderators, Science, Health & Environment Moderators Posts: 15,171 Mod ✭✭✭✭ Gonzo


    ECM brings a period of snow to much of the country tomorrow night as well.

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    no doubt this would have alot of rain also, and combined with a sleet and snow mix flooding is once again possible.

    Here is a sneaky peak at what the ECM is showing for next Thursday. Major pinch of salt.

    ECMWF_126_GB_SFC_fr-FR_fr.png


  • Registered Users Posts: 2,019 ✭✭✭ TimeLadsPlease


    Kermit > Gaoth Laidir :cool:

    Don't worry Kermit, if it snows you'll get the standard 246 thanks for starting the thread.


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  • Registered Users Posts: 21,787 ✭✭✭✭ Kermit.de.frog


    I'm only joking :pac:

    Looks good for northern counties. Snow turning to rain for most overnight tomorrow and just rain further south in south Leinster and Munster. Wouldn't be surprised if it was snow throughout in some northern counties.

    Looking forward to the reports even though it's unlikely I will see snow myself which sums the winter up for me really. :(


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