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Why has there not been much snow in this decade for Ireland compared to the last one?

  • 05-11-2017 3:08pm
    #1
    Banned (with Prison Access) Posts: 176 ✭✭ nigel_wilson


    I came to Ireland in 08' and although I learned that we didn't get the severity of cold weather/snow that mainland Europe does, it usually snowed mildly around Nov-Feb.

    The only real snow we experienced was during Nov to Dec 2010. I remember how everything stopped then. We haven't had anything snow afaik for 7 years. What's the meteorological explanation for this?

    I remember my Geog teacher said that the snow we got in 2010 was due to ice from the poles melting and bringing a 'wave' of cold sea water along with air that blocked the warm current from the Mid-Atlantic Drift. Is this true or not?


Comments

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


    Atlantic has warmed significantly in past 10 years
    Weather has been more mobile than normal
    More cloud has been prevalent at night reducing night frosts.
    Global temperatures have been slowly rising
    2010 was an exceptional year

    Theres some reasons


  • Registered Users Posts: 16,162 ✭✭✭✭ Sleeper12


    The only real snow we experienced was during Nov to Dec 2010. I remember how everything stopped then. We haven't had anything snow afaik for 7 years. What's the meteorological explanation for this?


    The previous time we had snow like that was 1982. I wouldn't be expecting another anytime soon


  • Closed Accounts Posts: 40,086 ✭✭✭✭ Harry Palmr


    We get a national snow covering every 10-12 years or so. We're in Ireland it'll always be a rare enough event. The only thing that marked out 2010 was that it was cold enough to stay on the ground for a week. Usually it's two days.


  • Registered Users Posts: 12,560 ✭✭✭✭ sryanbruen


    Snow is the most difficult thing to forecast in our country as everything has to be just right for it to take place with thunderstorms not being far behind in terms of difficulty of forecasting, even in the shortest term possible. First we have to look at how does snow occur? What even is it? The average person knows it as frozen rain. Here's the UK Met Office definition of Snow:
    Snow is a type of solid precipitation which occur in a variety of minute ice crystals at temperatures well below 0c but as larger snowflakes at temperatures near 0c. It is formed when temperatures are low and there is moisture trapped in the air or atmosphere above us. Tiny ice crystals in clouds stick together to become snowflakes. If enough crystals stick together, they'll become heavy to fall to the ground. Snowflakes that descend through wet air that is slightly warmer than 0c, will melt around the edges and stick together to produce big flakes. Snowflakes that fall through cold, dry air produce powdery snow that does not stick together.

    Our location around the world has a large say in why snow is difficult for us to record and get. We are in the mid-latitude yes but we're also surrounded with bodies of ocean/sea water that is milder than the land temperatures in Winter and cooler than the land temperatures in Summer. This situation can lead to rain around the coasts but snow a few miles inland.

    Secondly, the higher you are the more likely it is to snow due to temperature dropping with height. Like it may snow at a time on a mountain when everywhere else it rained. The Scottish mountains for example had their snowiest Winter for years in 2013/14.

    We often run into battleground situations where two contrasting air masses meet each other. Snow is possible at the line between the two air masses and perhaps blizzards (as it is the boundary between both air masses) but it vitally depends on which air mass wins the battle or which is more stubborn. Like a 1035hPa block is most likely to win the battle against a 990hPa low for example.

    Another factor is if the location is an urban or countryside area. Urban areas are less likely to get snow due to the warming effects of the surroundings and pollution.

    Last but not least on what can influence the recording of snow, if it rains continuously at a fairly high temperature like let's say 4-7c, it can cause the air temperature to drop and as a result, turn the rain to snow. This is due to heat being absorbed by the evaporation of water vapour from the raindrops as they fall.

    There are lots of possible reasons why snow has been far less frequently this decade although the 90s and 00s were far from perfect as well. I'd like to first state though that there was snow during early December 2011, Winter 2012/13 in early December in northern regions, during mid-January in scattered places, during February (early and late) and much of March. There was also snow in parts on 11 February 2014 as the winds turned into a northwesterly briefly after a front passed through overnight. Early February 2015 might have had some snow in parts but I'm not sure whilst early March 2015 brought some snow flurries. 2-4 March 2016 too brought some snow.

    Firstly, solar activity comes into play. Solar minimum took place in 2009. The best chance for cold winters according to research is just after solar minimum. Winters that took place just after solar minimum/around solar minimum include 2010/11, 2009/10, 1996/97, 1995/96, 1986/87, 1985/86, 1976/77, 1975/76, 1964/65, 1963/64 and 1962/63.

    Here are the IMTs for each of these Winters with their anomalies - bar 1964/65 and 1963/64 'cause I have not calculated them yet:

    2010/11 - 3.1 (-2.4c below the average)
    2009/10 - 2.6 (-2.9c below the average)
    1996/97 - 5.6 (+0.1c above the average) (February was exceptionally mild whilst January was near average with a very cold start and December was quite cold with -1.2c below the average)
    1995/96 - 5.1 (-0.4c below the average (December was very cold, February was quite cold and snowy but also stormy. January was very mild)
    1986/87 - 5.2 (-0.3c below the average)
    1985/86 - 3.6 (-1.9c below the average)
    1976/77 - 4.2 (-1.3c below the average)
    1975/76 - 6.1 (+0.6c above the average)
    1962/63 - 0.2 (-5.3c below the average)

    All information here is calculated by me from Met Éireann and UKMO's historical data

    As you can see from this data going back to Solar Cycle 19 (we're currently in #24), there was only one mild Winter near or at solar minimum - though I don't have the data from the other two Winters but going off of my memory, 1964/65 was cold with 1963/64 being close to average on the cooler side. Solar Cycle 24 has been the weakest Solar Cycle since #16 which was from 1923-1933. That was a poor period for cold Winters - a knock on effect for us now? Predictions show that scientists think Solar Cycle 25 will be even weaker and will eventually descend us into a new mini Ice Age. I won't go too much into that as it's a controversial topic and let's say, I'm not an expert on it.

    We should reach solar minimum by 2019/20 meaning that we are getting very close to be having our best chance of cold Winters.

    I'm sorry that I don't have time to continue it on from here, maybe another day I will.

    Weather and climate site - https://www.ukandirelandclimate.com/ (advised to view on PC, not optimised for mobile)

    Photography site - https://www.sryanbruenphoto.com/



  • Registered Users Posts: 12,560 ✭✭✭✭ sryanbruen


    pauldry wrote: »
    Atlantic has warmed significantly in past 10 years
    Weather has been more mobile than normal
    More cloud has been prevalent at night reducing night frosts.
    Global temperatures have been slowly rising
    2010 was an exceptional year

    Theres some reasons

    How has cloud been more prevalent at night may I ask (not saying you're wrong, I don't know) if sunshine averages overall have increased over time?

    I wouldn't put global temperatures rising aka global warming as a means for our weather though bar more frequent storms/heavier rainfalls.

    Weather and climate site - https://www.ukandirelandclimate.com/ (advised to view on PC, not optimised for mobile)

    Photography site - https://www.sryanbruenphoto.com/



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  • Moderators, Science, Health & Environment Moderators Posts: 15,181 Mod ✭✭✭✭ Gonzo


    the main thing that has changed in my opinion is that easterlys during Winter are becoming more rare, which is really curtains for any snow between Dundalk and Waterford. In the 80s we had them almost every winter, even if it was just for 1 day. In the 1990s we had at least 2 or 3 easterlys, with only 1 of them being a proper beast (1991). The 2000-2009 period didn't really have any significant easterly's, but there were some average ones, at my location we had a 24 hour easterly during 2008 which dumped over half a foot of snow which Dublin completely missed out on. 2009 also brought a 3 day spell around February and then there was 2010.

    Since 2010 there hasn't been a single snow event worth talking about through most of Leinster due to the lack of easterlys, maybe a rogue snizzle shower from the west or a weak band wintry slop from the Atlantic. So far this decade has nothing to report really. For me the years that stick out to me are 1982, 1987, 1991, 2010.

    Northern Ireland got very lucky in March 2013 I think it was with an insane snowfall and western Ireland generally get's its annual peppering of wintry showers from the Atlantic.


  • Registered Users Posts: 8,421 ✭✭✭ Danno


    C7gZbibXQAEUAuD.jpg:large

    March 22nd 2017 here in south Laois. 8cm+


  • Registered Users Posts: 8,421 ✭✭✭ Danno


    10479470_709967679117354_2755548877474590696_n.jpg?oh=10c6efa773231508b3c1220823ffe502&oe=5A64623A

    14th January 2015 3cm+


  • Registered Users Posts: 902 ✭✭✭ snowstorm445


    Gonzo wrote: »
    the main thing that has changed in my opinion is that easterlys during Winter are becoming more rare, which is really curtains for any snow between Dundalk and Waterford. In the 80s we had them almost every winter, even if it was just for 1 day. In the 1990s we had at least 2 or 3 easterlys, with only 1 of them being a proper beast (1991). The 2000-2009 period didn't really have any significant easterly's, but there were some average ones, at my location we had a 24 hour easterly during 2008 which dumped over half a foot of snow which Dublin completely missed out on. 2009 also brought a 3 day spell around February and then there was 2010.

    Since 2010 there hasn't been a single snow event worth talking about through most of Leinster due to the lack of easterlys, maybe a rogue snizzle shower from the west or a weak band wintry slop from the Atlantic. So far this decade has nothing to report really. For me the years that stick out to me are 1982, 1987, 1991, 2010.

    Northern Ireland got very lucky in March 2013 I think it was with an insane snowfall and western Ireland generally get's its annual peppering of wintry showers from the Atlantic.

    Also important to remember that even if easterlies are a possibility there’s always the chance Ireland will be too far west for them to make an impact. Great Britain and Mainland Europe might receive a proper blast of snow while Ireland is left on the mild side, like we saw in early 2012 (I think?) We really do have to strike gold for them to deliver a decent cold spell.

    I remember that one in 2008 actually, was in Drogheda at the time and it was gone in about a day, but it managed to dump about half a foot of snow overnight (and a bit of thunder thrown in too). Really shows you the power of any sort of easterly spell. If the cold northwesterlies we get every winter had anything like the effects of easterlies we would be covered in snow for large parts of the winter.


  • Registered Users Posts: 12,560 ✭✭✭✭ sryanbruen


    Danno wrote: »
    10479470_709967679117354_2755548877474590696_n.jpg?oh=10c6efa773231508b3c1220823ffe502&oe=5A64623A

    14th January 2015 3cm+

    I forgot about Storm Rachel’s snow oops and yeah wasn’t sure if lowlands recorded snow in March 2017.

    Ye snowstorm, it was early February 2012. Ireland got so damn unlucky. It was a very mild February at an IMT of 7.2c which comes to +1.9c above the average.

    Weather and climate site - https://www.ukandirelandclimate.com/ (advised to view on PC, not optimised for mobile)

    Photography site - https://www.sryanbruenphoto.com/



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  • Closed Accounts Posts: 695 ✭✭✭ beefburrito


    Gonzo wrote: »
    the main thing that has changed in my opinion is that easterlys during Winter are becoming more rare, which is really curtains for any snow between Dundalk and Waterford. In the 80s we had them almost every winter, even if it was just for 1 day. In the 1990s we had at least 2 or 3 easterlys, with only 1 of them being a proper beast (1991). The 2000-2009 period didn't really have any significant easterly's, but there were some average ones, at my location we had a 24 hour easterly during 2008 which dumped over half a foot of snow which Dublin completely missed out on. 2009 also brought a 3 day spell around February and then there was 2010.

    Since 2010 there hasn't been a single snow event worth talking about through most of Leinster due to the lack of easterlys, maybe a rogue snizzle shower from the west or a weak band wintry slop from the Atlantic. So far this decade has nothing to report really. For me the years that stick out to me are 1982, 1987, 1991, 2010.

    Northern Ireland got very lucky in March 2013 I think it was with an insane snowfall and western Ireland generally get's its annual peppering of wintry showers from the Atlantic.

    You're definitely right about the Easterly winds.
    In fishing and Surfing we call them offshore winds.
    These offshore breeze's and winds flattens the Atlantic....and combined the Easterly winds and south Westerly swells bring in beautiful surfable waves.
    I remember back from 2011 back there was always periods of offshore winds and glassy ocean conditions.

    A lot of you here are well up in the scientific explanation of the weather.

    Hopefully we'll get plenty of Easterly winds this winter and it'll be much drier.

    And some snow thrown in for good measure.


  • Registered Users Posts: 12,560 ✭✭✭✭ sryanbruen


    You're definitely right about the Easterly winds.
    In fishing and Surfing we call them offshore winds.
    These offshore breeze's and winds flattens the Atlantic....and combined the Easterly winds and south Westerly swells bring in beautiful surfable waves.
    I remember back from 2011 back there was always periods of offshore winds and glassy ocean conditions.

    A lot of you here are well up in the scientific explanation of the weather.

    Hopefully we'll get plenty of Easterly winds this winter and it'll be much drier.

    And some snow thrown in for good measure.

    "Much drier"

    Was last Winter not enough for ya? :P

    Weather and climate site - https://www.ukandirelandclimate.com/ (advised to view on PC, not optimised for mobile)

    Photography site - https://www.sryanbruenphoto.com/



  • Closed Accounts Posts: 695 ✭✭✭ beefburrito


    sryanbruen wrote: »
    "Much drier"

    Was last Winter not enough for ya? :P

    Ha ha never enough......
    Last winter the swells and Easterly winds didn't combine right.

    The second period between the wave's wasn't good enough....14 seconds is about right.

    Although when Lahinch was battered a few years ago there was 21 seconds between each wave.

    The longer the period between each wave the bigger the bow.....

    You could have a 3 foot swell with 17 seconds between each wave,and an 8 foot swell with 8 seconds.....

    The 3 foot period would be way bigger on the face.....

    The winter swells have longer pulse's between wave's...

    Sorry for going off topic guy's


  • Registered Users Posts: 8,421 ✭✭✭ Danno


    1620442_532851170162340_468089527_n.jpg?oh=1d38b5c11ec564fe211fa406b73b49b4&oe=5A72C019

    11th February 2014


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