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Winter 2017-18: Discussion

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  • Registered Users Posts: 16,550 ✭✭✭✭nacho libre


    I have a feeling we are going to have a January 2018 that is akin to the blowtorch ones of the early nineties, southerly winds with occluded fronts dominating the month, with temperatures reaching 15 degrees in places. Incidentally what's the highest temperature ever recorded for January in Ireland?


  • Registered Users Posts: 13,477 ✭✭✭✭sryanbruen


    I have a feeling we are going to have a January 2018 that is akin to the blowtorch ones of the early nineties, southerly winds with occluded fronts dominating the month, with temperatures reaching 15 degrees in places. Incidentally what's the highest temperature ever recorded for January in Ireland?

    18.5c on the 10th January 1998.
    sryanbruen wrote: »
    Ireland's all-time maximum temperatures for each month of the year

    January - 18.5c at Glasnevin, Co. Dublin on the 10th in 1998

    February - 18.1c at Phoenix Park, Co. Dublin on the 23rd in 1891

    March - 23.6c at Trinity College, Co. Dublin on the 28th in 1965

    April - 25.8c at Glenties, Co. Donegal on the 26th in 1984

    May - 28.4c at Ardfert, Co. Kerry on the 31st in 1997 (28.3c was recorded at the same place on the 25th in 2012.... only 0.1c short of the record)

    June - 33.3c at Kilkenny Castle, Co. Kilkenny on the 26th in 1887

    July - 32.3c at Elphin, Co. Roscommon on the 19th in 2006

    August - 31.5c at Ballybrittas, Co. Laois on the 3rd in 1975 & Oak Park, Co. Carlow on the 2nd in 1995

    September - 29.1c at Clongowes Wood College, Co. Kildare on the 1st in 1906

    October - 25.2c at Clongowes Wood College, Co. Kildare on the 3rd in 1908

    November - 20.1c at Dooks, Co. Kerry on the 1st in 2015

    December - 18.1c at Peamount, Co. Dublin on the 2nd in 1948

    Originally sourced from

    http://www.met.ie/climate-ireland/extreme_maxtemps.pdf

    With November's maximum edited to the recent record in 2015.


  • Registered Users Posts: 13,477 ✭✭✭✭sryanbruen


    Loughc wrote: »
    Possibly imagining this but does it feel colder so far this September compared to last few years?

    I don't have figures for September 2017 because I calculate the IMT at the end of the month. But here's the IMTs for the past Septembers since 2006 to compare along with their anomalies from average:

    2016: 14.2 (+1.2)
    2015: 11.9 (-1.1)
    2014: 14.4 (+1.4)
    2013: 13.8 (+0.8)
    2012: 11.9 (-1.1)
    2011: 13.8 (+0.8)
    2010: 13.7 (+0.7)
    2009: 13.2 (+0.2)
    2008: 12.7 (-0.3)
    2007: 13.2 (+0.2)
    2006: 15.1 (+2.1)

    Sourced from Met Éireann's historical data and the Met Office's Northern Ireland data


  • Registered Users Posts: 7,095 ✭✭✭pad199207


    sryanbruen wrote: »
    18.5c on the 10th January 1998.

    Clongowes is in Kildare not Clare


  • Registered Users Posts: 13,477 ✭✭✭✭sryanbruen


    pad199207 wrote: »
    Clongowes is in Kildare not Clare

    Thank you for that.


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  • Registered Users Posts: 14,240 ✭✭✭✭leahyl


    For gods sake, I really hope we don't get another mild winter - nothing seasonal about it ☹️


  • Moderators, Science, Health & Environment Moderators Posts: 16,677 Mod ✭✭✭✭Gonzo


    leahyl wrote: »
    For gods sake, I really hope we don't get another mild winter - nothing seasonal about it ☹️

    I'm beginning to accept it as normal that Ireland will see a mild winter almost every single winter. It's normal at this stage. It's now a rarity to see a winter with more than a day of widespread lying snow lasting more than a day.


  • Moderators, Business & Finance Moderators, Recreation & Hobbies Moderators Posts: 24,649 Mod ✭✭✭✭Loughc


    Loughc wrote: »
    Possibly imagining this but does it feel colder so far this September compared to last few years?

    And as soon as I say that it's followed by a very mild week.... :o

    Good thing I'm not trying to predict Weather Patterns, I'd be awful at that!


  • Registered Users Posts: 6,834 ✭✭✭pauldry


    IMT currently 12.66c in relation to above question.

    Around normal or mild for rest of month


  • Registered Users Posts: 17,797 ✭✭✭✭hatrickpatrick


    NAO looks to be trending negative? Too early to say obviously but most of the spaghetti predictions seem to be on the negative side.

    nao.sprd2.gif


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  • Registered Users Posts: 5,479 ✭✭✭giveitholly


    NAO looks to be trending negative? Too early to say obviously but most of the spaghetti predictions seem to be on the negative side.

    nao.sprd2.gif
    In laymans language what does this mean


  • Registered Users Posts: 199 ✭✭IMBACKLATER


    In laymans language what does this mean

    Risk of Colder winter in North America and europe


  • Registered Users Posts: 13,477 ✭✭✭✭sryanbruen


    In laymans language what does this mean

    LOL, it means that high pressure will build up over Greenland/Iceland with the Azores High weakening, and depending on the "negativity levels" of the North Atlantic Oscillation, it can be destroyed. March 2013 was a case where the NAO was very negative and the Azores High destroyed. With no Azores High up to allowing us mild westerlies with Atlantic depressions and the high pressure up to the north or Greenland/Iceland etc, it meant that we could only get easterlies - winds from Siberia which gave us a very cold March.

    Every Summer from 2007 to 2017 bar 2013 & 2017 have had a negative NAO which is one of the few reasons why Summers have been feeling terrible since 2007 for the most part in Ireland. In Summer, you want a positive NAO because the Azores High will be intensified and you want it to build over Ireland but rarely does like in July 2013 when we had a 2 week warm/hot spell. 2013 had a positive NAO which is no surprising given what I just said about July 2013 whilst 2017 just gone had a very slightly positive NAO or perhaps neutral NAO. Like with Winter, never a guarantee however that you'd get good Summer conditions or in Winter's case with a negative NAO, cold conditions.

    Winter 1990/91 was the third coldest Winter in the past two decades after 2009/10 and 2010/11. However, it had a positive NAO and a positive AO. This meant the Azores High and Polar Vortex (the Polar Vortex traps all the cold in the Arctic) were strong.... even though we had quite a cold Winter with early February in particular being cold.

    Is this too complicated for you? :P


  • Registered Users Posts: 17,797 ✭✭✭✭hatrickpatrick


    Like everything weather-related it's just one ingredient of a whole set of factors which have to line up, but it would be good news for a potentially interesting winter if we had a persistently negative NAO. There's a lot of divergence in that model graphic I posted, but it looks to me (someone else can chime in and clarify if I'm wrong here?) as if the general trend at the moment is neutral to negative.


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


    NAO is just number used to describe the pressure difference across the north Atlantic, strong Azores high + deep Icelandic low = positive NAO. Weak Azores and shallow Icelandic low = negative NAO

    Generally positive means we get unsettled westerlies, negative means we get slow moving weather systems which depending on luck can be anything from settled high pressure to stalling low pressure systems


  • Registered Users Posts: 17,797 ✭✭✭✭hatrickpatrick


    NAO is just number used to describe the pressure difference across the north Atlantic, strong Azores high + deep Icelandic low = positive NAO. Weak Azores and shallow Icelandic low = negative NAO

    Generally positive means we get unsettled westerlies, negative means we get slow moving weather systems which depending on luck can be anything from settled high pressure to stalling low pressure systems

    Negative can also cause the Atlantic to block, which can allow lovely Arctic lows to drift southwards towards us. Far from guaranteed, but it's certainly one nice ingredient to have in the search for a wintry spell.


  • Registered Users Posts: 989 ✭✭✭MrDerp


    FWIW:

    https://business.weather.com/news/european-seasonal-outlook-the-weather-company-expects-a-warm-and-dry-fall-for-northern-eastern-europe

    It’s a next 3 months forecast but predicts a colder than normal December and more prevalent blocking than in previous 4 winters.
    While it is still quite early, we expect a higher frequency of cold spells this winter across northern/Western Europe, especially later in the winter

    I’m off to buy some snow boots


  • Registered Users Posts: 6,126 ✭✭✭screamer


    I don't know anything about weather models or trends but I think this winter will be colder in general. Perhaps not snowy but definitely colder than the past few years. The weather has just turned too quickly this year and after a half decent summer I think that we'll pay for it with a cooler winter.....


  • Registered Users Posts: 13,477 ✭✭✭✭sryanbruen


    The OPI (October Pattern Index) has been dead since 2014. It was used as a methodology for the forecasting of Winter 2014/15. It tells you the state of the atmosphere over the northern half of Europe. If there's blocking whether over Greenland, Scandinavia or the Arctic, the OPI is likely to be on the negative side. If there is a lack of blocking, you should expect the OPI to be on the positive side. This was a university project made by an Italian man named Riccardo. Unfortunately, October 2014's OPI was the second most negative going back to 1976 (the furthest back it's been calculated) with October 2009 being the most negative. This meant that according to the OPI, Winter 2014/15 would have a lot of blocking or a negative AO. This was a huge fail and did not turn out like that at all. As a result, the OPI was left dead by forecasters and including Riccardo.

    Nevertheless, despite this huge fail, the OPI continues to be the most accurate Winter methodology you can find. It holds an accuracy % of more than 80 which is ridiculous and unbelievable. Before Winter 2013/14, it held an accuracy of 91%.

    There are no confirmed OPI values for October 2015 & 2016 but from my estimations, the OPI for October 2015 was on the positive side although close to neutral on the positive side whilst the OPI for October 2016 was on the negative side. With the OPI, it's no surprise given my estimation how Winter 2015/16 turned out. Meanwhile, October 2016 was negative (from my estimation). Winter 2016/17 was very dry but mild.

    Seeing the early prospects for October 2017 here from the models, the chances of a negative OPI look very possible. However, it's a long way to go 'til October finishes up. Just remember that in recent years such as 2014/15, the OPI has failed in predicting the mean AO for the following Winter.

    A negative OPI is a good starting point though if it does come off.

    Frankly, this index is very controversial to me but due to its ridiculous accuracy, I have to consider it and think it should not be forgotten just because of one fail or flop.


  • Registered Users Posts: 599 ✭✭✭Captain Snow




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  • Registered Users Posts: 18,079 ✭✭✭✭JCX BXC


    Fairly content with the possibility of some good storms this winter, nice and interesting.

    Of course then I decided to read back over a few snow threads. Let's just say I think it'll be another winter of disappointment in that aspect! :(


  • Moderators, Science, Health & Environment Moderators Posts: 16,677 Mod ✭✭✭✭Gonzo


    I am expecting no more than the usual Atlantic cold snap with a 3 hour brief dusting or snizzle with showers dying out as they move east/southeast. Hope i'm wrong.


  • Registered Users Posts: 13,477 ✭✭✭✭sryanbruen


    Gonzo wrote: »
    I am expecting no more than the usual Atlantic cold snap with a 3 hour brief dusting or snizzle with showers dying out as they move east/southeast. Hope i'm wrong.

    Sorry that's too much to ask for, you are not allowed even one second of a snowflake :cool: - Mother Nature in a nutshell.


  • Closed Accounts Posts: 2,520 ✭✭✭nagdefy


    Lads do ye not know that this science is only a cod and anything could happen this winter ;)



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


    nagdefy wrote: »
    Lads do ye not know that this science is only a cod and anything could happen this winter ;)


    Comedy Gold!!! :D


  • Registered Users Posts: 13,477 ✭✭✭✭sryanbruen


    Floki wrote: »
    Getting off topic a little bit but I'm looking at the colours for the North Atlantic.

    Is that what they call a tri pole?
    And what does that normally mean for 'our' weather?

    This is a tri pole (see the North Atlantic Ocean) in the chart below that I have marked. The bands have to go in that order: warm, cold and warm. If they don't, it's not a tri pole. A tri pole in other words is a very negative NAO index. You don't need to have a tri pole to have a negative NAO index as long as there is blocking up to Greenland, Iceland or the Arctic.

    A tri pole in May before the Winter is a methodology used and made by the UK Met Office since the late 2000s. This is because there is evidence according to the UKMO that if a tri pole occurs in May, it has a high chance of being there for the succeeding Winter. They say May specifically because on average, it is the month of the year where westerlies are at their lowest strength. This leads to the higher likelihood of other wind directions such as northerlies or easterlies development which according to the evidence can carry on into the Winter. 2010 was such an example. May 2010 had a tri pole as you can see in the chart and then the December to remember took place in the Winter succeeding it.

    Whilst a negative NAO can still bring a mild Winter such was the case in 1997/98 though in my opinion that was down to a Very Strong El Nino event taking place then, a tri pole has a very small likelihood of bringing a mild Winter. Even saying that, do not rely on the tri pole method or NAO for predicting the Winter. Everything else has to setup just right with these which is why it's so hard for us to get snow or cold winters.

    The current SST anomalies in the Atlantic is not a tri pole as the majority of the Atlantic is just rather warm. But it is not far from a tri pole!

    gGyzgUb.gif


  • Registered Users Posts: 6,834 ✭✭✭pauldry


    More and more i think this Winter will be just front after front with short dry spells and NW to SW winds....like now.

    Nothing spectacular


  • Registered Users Posts: 9,230 ✭✭✭sdanseo


    Danno wrote: »
    Comedy Gold!!! :D

    It's beyond funny though, he shouldn't be allowed lie to the Dáil.

    Some of the crap he comes out with. He just said the famine was "in the 1740s" and that "the records will prove that".

    It was in the 1840s and caused by a lot more than just the weather.


  • Closed Accounts Posts: 2,520 ✭✭✭nagdefy


    sdanseo wrote: »
    It's beyond funny though, he shouldn't be allowed lie to the Dáil.

    Some of the crap he comes out with. He just said the famine was "in the 1740s" and that "the records will prove that".

    It was in the 1840s and caused by a lot more than just the weather.

    He's 100% right on the 1740-41 famine. Proportionately many more killed than during the potato famine of the 1840s.

    https://en.wikipedia.org/wiki/Irish_Famine_(1740%E2%80%9341)

    Also a bug bear of mine is people tend to think there was only one irish famine. Post Cromwell 1660s a very bad one, late 1870s, 1890 in parts of the country to name just a few off the top of my head. Most centuries had a few famines. Well documented in The Annals of the Four Masters etc.


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  • Registered Users Posts: 9,230 ✭✭✭sdanseo


    nagdefy wrote: »
    He's 100% right on the 1740-41 famine. Proportionately many more killed than during the potato famine of the 1840s.

    https://en.wikipedia.org/wiki/Irish_Famine_(1740%E2%80%9341)

    Also a bug bear of mine is people tend to think there was only one irish famine. Post Cromwell 1660s a very bad one, late 1870s, 1890 in parts of the country to name just a few off the top of my head. Most centuries had a few famines. Well documented in The Annals of the Four Masters etc.

    Every day's a school day. Still can't stand him though :D


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