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Winter 2017-18: Discussion

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Comments

  • Registered Users, Registered Users 2 Posts: 5,068 ✭✭✭Iancar29


    First time this season ( that I know of ) that wintry ppn showing up on radar. However with current temp/dps I think its just picking up hail. Still good to see though.

    432494.jpg


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


    MJohnston wrote: »
    No, that’s not accurate. Your opinion is less valid because your posts communicate far less scientific understanding or intelligence. All opinions are not equal, as meteorology is not a philosophical arena, it is a scientific one.

    All opinions are not equal...

    I have the utmost respect for MT and the work he does on the weather fora. Also others like sryan who attempt to make long range predictions based on science.

    I'd argue though that Evelyn Cusack and Met Eireann's opinions on Long Range Forecasting are as equal and valid as anyone on this site though.

    I'd agree with those opinions expressed at 1min 16sec in from 3 years ago. See below.



    Though her last quote from Sagon is a little pop at religion i feel, which is out of order for a weather forecast. I feel she's bringing her own personal beliefs into a weather forecast.


  • Registered Users, Registered Users 2 Posts: 18,228 ✭✭✭✭JCX BXC


    Well made point.

    I wouldn't entirely agree, I think there are some general weather factors that can help us understand weather in the future to a degree, however they aren't suitable for saying with any definite degree that you'll get xxx weather. However, organisations like Met Eireann are forecasting what the weather will most likely be like, they're not in the game of giving uncertain probabilities outside the reliable range.

    Nobody will be ever able to say "this winter will be very snowy" or "this winter will have no snow whatsoever", as they are very specific, but general terms like MT thinking this winter will be slightly cooler than average are possibly in my opinion.


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


    JCX BXC wrote: »
    Well made point.

    I wouldn't entirely agree, I think there are some general weather factors that can help us understand weather in the future to a degree, however they aren't suitable for saying with any definite degree that you'll get xxx weather. However, organisations like Met Eireann are forecasting what the weather will most likely be like, they're not in the game of giving uncertain probabilities outside the reliable range.

    Nobody will be ever able to say "this winter will be very snowy" or "this winter will have no snow whatsoever", as they are very specific, but general terms like MT thinking this winter will be slightly cooler than average are possibly in my opinion.

    I understand. Personally i feel that when we review LRFs in early March they are a complete mixed bag and are never much stronger than guess work. Again it's only my opinion and i in no way mean to insult anyone or their views. I suppose every year science is developing too and more variables are being input into forecasts.


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


    Re. LRFs maybe a month out but i find it hard to accept a prediction for mid January.


  • Registered Users Posts: 1,394 ✭✭✭esposito


    Danno wrote: »

    So, overall it's the turn of the west to get snow this winter, hopefully the midlands too if the wind can carry showers in this far. Maybe a polar low might come down in the flow also.

    Don't take it as gospel that it will turn out like that. I think it's just too damn difficult to predict with any accuracy beyond a month.


  • Closed Accounts Posts: 3,378 ✭✭✭HighLine


    Fully agree with the actual experts, namely Evelyn above, who call it like it as in saying long range forecasting is not possible. It's funny however on here how some tabloids and the likes of Ken Ring are correctly ridiculed but other posters suggesting they can predict how our weather will be in February 2018 are encouraged. Especially strange considering how inaccurate previous long range attempts have been.


  • Registered Users, Registered Users 2 Posts: 6,238 ✭✭✭Oneiric 3


    nagdefy wrote: »
    All opinions are not equal...
    Though her last quote from Sagon is a little pop at religion i feel, which is out of order for a weather forecast. I feel she's bringing her own personal beliefs into a weather forecast.

    It's always amused me that scientists in particular are quick to attribute that particular quote to Carl Sagan, when it fact is by Danish social scientist Marcello Truzzi. Have the greatest respect for scientists, but they often strike me as not really having much clue about anything outside of their field.

    New Moon



  • Registered Users, Registered Users 2 Posts: 13,666 ✭✭✭✭sryanbruen


    nagdefy wrote: »
    All opinions are not equal...

    I have the utmost respect for MT and the work he does on the weather fora. Also others like sryan who attempt to make long range predictions based on science.

    I'd argue though that Evelyn Cusack and Met Eireann's opinions on Long Range Forecasting are as equal and valid as anyone on this site though.

    I'd agree with those opinions expressed at 1min 16sec in from 3 years ago. See below.



    Though her last quote from Sagon is a little pop at religion i feel, which is out of order for a weather forecast. I feel she's bringing her own personal beliefs into a weather forecast.

    Thanks. I try to keep my forecasting as accurate as possible with the methodology I use.

    I acted like a dick before saying I know what’s going to happen for absolute certain - me being one of the posters I think HighLine was getting at in his above comment.

    He is right. Long range forecasting is impossible and is highly experimental. You’re either right through science/complete random guesses or not. No certainty whatsoever.

    I have respect for people like MT because he actually tries to put work into making these predictions unlike somebody like let’s say James Madden, Nathan Rao etc. But even that isn’t any different at the end of the day as it’s still experimental and a complete guess. You will always find odd ones out with the methodology we use to predict our weather. Our atmosphere is always willing to give us some surprises.


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


    sryanbruen wrote: »
    Thanks. I try to keep my forecasting as accurate as possible with the methodology I use.

    I acted like a dick before saying I know what’s going to happen for absolute certain - me being one of the posters I think HighLine was getting at in his above comment.

    He is right. Long range forecasting is impossible and is highly experimental. You’re either right through science/complete random guesses or not. No certainty whatsoever.

    I have respect for people like MT because he actually tries to put work into making these predictions unlike somebody like let’s say James Madden, Nathan Rao etc. But even that isn’t any different at the end of the day as it’s still experimental and a complete guess. You will always find odd ones out with the methodology we use to predict our weather. Our atmosphere is always willing to give us some surprises.

    I wouldn't think anyone is having a go at MT or yourself Sryan as you outline step by step why you are predicting whatever conditions and back it up with historical context. It's interesting to have a go.

    Your knowledge is increasing year on year and i have a feeling in 5 years time your predictions will be as accurate as any out there:) We're probably still a few decades off real LRF accuracy though in my opinion and many will say there are too many factors and it's nigh on impossible. We'll see. Who knows.

    Just felt at the end of the report i copied Evelyn was have a nice go at those clinging to the comfort of delusion as if science had proved absolutely everything at this stage of human development. Personally i'd find that a little offensive.


  • Registered Users Posts: 10,666 ✭✭✭✭MJohnston


    I'm sure MT can speak for his own methodology but it seems to me less forecasting, more outlining the longer-lasting conditions that he calls "global drivers" and then speaking about the kind of weather conditions they make more likely to happen.

    So, Pacific Decadal Oscillation or Solar Cycles are looking likely to be X or Y, and that is likely to create the conditions for A or B types of weather. Of course he throws some actual predictions on top there, but at least it's probabilistic and well explained.

    In the end I'd rather hear about experimental, yet scientifically founded "guesses" rather than some people who demonstrate precisely zero scientific understanding and say something reductive like it's all a spoof.


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


    MJohnston wrote: »
    I'm sure MT can speak for his own methodology but it seems to me less forecasting, more outlining the longer-lasting conditions that he calls "global drivers" and then speaking about the kind of weather conditions they make more likely to happen.

    So, Pacific Decadal Oscillation or Solar Cycles are looking likely to be X or Y, and that is likely to create the conditions for A or B types of weather. Of course he throws some actual predictions on top there, but at least it's probabilistic and well explained.

    In the end I'd rather hear about experimental, yet scientifically founded "guesses" rather than some people who demonstrate precisely zero scientific understanding and say something reductive like it's all a spoof.

    I agree MJ with most of what you are saying and as i outlined in previous posts MT etc use the Science available.

    Just the bit i emboldened. I think the burden of proof in making a long range forecast is on the long range forecaster, not the person who dismisses it without proof?


  • Registered Users, Registered Users 2 Posts: 1,826 ✭✭✭NickNickleby


    Hi everybody.
    I watch the weather forum a lot. Especially after Halloween! I have great admiration for those of you who can gather and interpret data, and then go on to make educated 'guesses' as to how the weather will behave in the future. We all know they're not guesses at all, but I don't say prediction because to me that suggests certainty, and with this stuff how could anyone be CERTAIN.

    My opinion on weather is that its like getting a pot of hot water, stirring it gently, then adding various amounts of warmed dyed water in different parts, then predicting how that will affect a very specific location in the pot. Of course, with absolutely mad levels of data collection, over many cycles, and a super-duper computer , it might be possible to make a prediction on the next attempt.

    As you can tell from my hamfisted previous paragraph, I know sod all about meteorology, but I think I can appreciate the difficult science required. (I actually thought of this one evening while pouring milk into my tea!:D

    Keep it up guys, like most people on here, I admire and appreciate your efforts.


  • Registered Users Posts: 10,666 ✭✭✭✭MJohnston


    nagdefy wrote: »
    I agree MJ with most of what you are saying and as i outlined in previous posts MT etc use the Science available.

    Just the bit i emboldened. I think the burden of proof in making a long range forecast is on the long range forecaster, not the person who dismisses it without proof?

    Well, what I'd say is there's a burden on the forecaster to fully justify the predictions they're making with "proof" (which I would simply see as a solid scientific reasoning), but there is no burden on the forecaster to ensure that every single layman understands them.

    Sometimes with people, there's an immediate attitude of dismissal of things they don't understand, and it's not because the expert hasn't proven themselves.


  • Registered Users, Registered Users 2 Posts: 6,238 ✭✭✭Oneiric 3


    sryanbruen wrote: »
    let’s say James Madden, Nathan Rao etc.

    hJSuAps.gif

    New Moon



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  • Registered Users, Registered Users 2 Posts: 6,238 ✭✭✭Oneiric 3


    If one was to make a long range prediction based long term averages alone, I wonder if one could make maybe make fairly reasonable long-range forecast? though of course, weather rarely follows a set pattern on a year by year basis.

    However, this chart I generated showing the 1981-2010 MSLP pattern (based on a running 7 day period) for the country as a whole for the winter season, does show a fairly interesting pattern, with 3 major 'dips', occurring at specific intervals, namely: end of December, mid-late Jan and mid Feb, which would indicate that, on average, the most unsettled spells of the Winter season are likely to occur at these times. Same would with peaks, which would suggest 3 or 4 relatively settled periods to occur at fairly specific intervals in the season.

    sni.png


    Data from the ECMWF.

    New Moon



  • Registered Users, Registered Users 2 Posts: 2,682 ✭✭✭Rougies



    My opinion on weather is that its like getting a pot of hot water, stirring it gently, then adding various amounts of warmed dyed water in different parts, then predicting how that will affect a very specific location in the pot. Of course, with absolutely mad levels of data collection, over many cycles, and a super-duper computer , it might be possible to make a prediction on the next attempt.

    As you can tell from my hamfisted previous paragraph, I know sod all about meteorology, but I think I can appreciate the difficult science required. (I actually thought of this one evening while pouring milk into my tea!:D

    That's not a bad analogy at all.

    You reminded me of this great little paragraph:

    Imagine a rotating sphere that is 12,800 kilometers (8000 miles) in diameter, has a bumpy surface, is surrounded by a 40-kilometer-deep mixture of different gases whose concentrations vary both spatially and over time, and is heated, along with its surrounding gases, by a nuclear reactor 150 million kilometers (93 million miles) away. Imagine also that this sphere is revolving around the nuclear reactor and that some locations are heated more during one part of the revolution and other locations are heated during another part of the revolution. And imagine that this mixture of gases continually receives inputs from the surface below, generally calmly but sometimes through violent and highly localized injections. Then, imagine that after watching the gaseous mixture, you are expected to predict its state at one location on the sphere one, two, or more days into the future. This is essentially the task encountered day by day by a weather forecaster (Ryan, Bulletin of the American Meteorological Society,1982).


  • Registered Users Posts: 3,167 ✭✭✭Rebelbrowser


    Oneiric 3 wrote: »
    If one was to make a long range prediction based long term averages alone, I wonder if one could make maybe make fairly reasonable long-range forecast? though of course, weather rarely follows a set pattern on a year by year basis.

    However, this chart I generated showing the 1981-2010 MSLP pattern (based on a running 7 day period) for the country as a whole for the winter season, does show a fairly interesting pattern, with 3 major 'dips', occurring at specific intervals, namely: end of December, mid-late Jan and mid Feb, which would indicate that, on average, the most unsettled spells of the Winter season are likely to occur at these times. Same would with peaks, which would suggest 3 or 4 relatively settled periods to occur at fairly specific intervals in the season.

    sni.png


    Data from the ECMWF.

    Just from experience, it is amazing how often it is mild on Christmas day but colder by 28/29 December. Your chart seems to support that somewhat. 2010 was admittedly the very opposite but more a case of the exception proving the rule I think.


  • Registered Users, Registered Users 2 Posts: 14,585 ✭✭✭✭M.T. Cranium


    The main point of disagreement I would have with the critical comments is that when I describe a mix of weather types during the winter, this is

    (a) normally what happens, and

    (b) in my forecast, is tied to fairly specific periods so that actually it is not an effort to muddy the waters by saying everything might happen, but an attempt to say when the various components will happen.

    Also I attempt to give some idea of the relative frequency of the different types compared to normal. This winter, I think very mild weather might be less frequent than it has been in several recent winters, and colder than average temperatures might be more frequent. That is fairly specific, then I go into some details about when I foresee these trends.

    As several have noted, the pursuit of long-range forecasting is a science under development, and nobody seriously involved in it would argue that it is a developed science (the way astronomy is a developed science, I went to Baker City Oregon last August 21st expecting to see a total eclipse of the Sun at 10:22 a.m. and one thought that crossed my mind when it actually happened was, what are we doing wrong in our science?) :)

    On the other hand, the general state of long-range forecasting in North America seems to be a bit further advanced, perhaps because we have a more variable climate so that different regimes show their hand a bit earlier? It seems to me that most of the errors in LRF here are matters of degree or exact boundaries between regimes, and quite often the large scale picture is what many forecasters have said they expect. This is especially true when there's an El Nino. For Europe, I suspect it is more difficult because variations are smaller and everything depends on blocking or no blocking, we can get our cold weather more directly with a continent between us and source regions for arctic air.

    So none of this has changed much since I got involved in the subject over ten years ago, and it probably doesn't help that in the background of the science (but in the foreground of public perception) we have these same few people making exactly the same forecast (worst winter ever) time after time. I think that is skewing perception because serious students of this difficult (and admittedly rudimentary) science would not expect the same thing to happen every winter.

    I found the pressure analysis above to be interesting, I suspect it may have to do with background pressure variations in the atmosphere caused by interactions between the Sun and sources of gravitational energy. Although the curves look quite pronounced, Oneiric would probably agree that differences of 5 to 10 mb are not a large component of the overall variability (which is closer to 50-100 mb). So if this were the only factor at work, we would just see a slight uptick in storminess around those times of lower pressures.

    I analyzed some pressure stats for Malin Head over a roughly similar period and found significant troughs (10-15 mb) around the times of new and full moons in December and January. This tendency fades out in February and March. Some time I might start a thread about some research I've done into the dynamics that might be causing those oscillations, but even 10-15 mb, while it may sound significant, is a rather small portion of the overall variability.

    I have come to less dramatic conclusions than Ken Ring about lunar effects, but I think the Moon does have some influence on atmospheric variations, however, it is not a strong enough signal to dominate so it has to work with larger scale variations that are caused by independent factors. My research shows that you can get some fairly large signals if you divide the data into groups of similar weather patterns, as opposed to trying to find the signals in all the data. However, I might have to live about five centuries to get anywhere near the end of the trail in this research so as that's not too likely I am hoping to get it at least adequately described before I pass, then somebody else can have the fun I've had trying to decode all of this.


  • Registered Users, Registered Users 2 Posts: 8,913 ✭✭✭Danno


    nagdefy wrote: »
    Though her last quote from Sagon is a little pop at religion i feel, which is out of order for a weather forecast. I feel she's bringing her own personal beliefs into a weather forecast.

    Exactly, it's very condescending and has no place in a publicly funded broadcast from a publicly funded organisation. I abhor those who use their fields of expertise to have a cut from "above" whilst equally I despise comments directed at organisations that try to do their best - i.e. unwarranted abuse of forecasts gone wrong by Met Eireann, etc...


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  • Registered Users, Registered Users 2 Posts: 18,228 ✭✭✭✭JCX BXC


    Danno wrote: »
    Exactly, it's very condescending and has no place in a publicly funded broadcast from a publicly funded organisation.

    While I don't disagree with the point, I'd like to point out that before the news starts, what do we have? The Angeles.


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


    Danno wrote: »
    Exactly, it's very condescending and has no place in a publicly funded broadcast from a publicly funded organisation. I abhor those who use their fields of expertise to have a cut from "above" whilst equally I despise comments directed at organisations that try to do their best - i.e. unwarranted abuse of forecasts gone wrong by Met Eireann, etc...

    I think it was on the TV3 night show that she was giggling away at Danny Healy Rae's climate views. We all know Danny HR doesn't have the most enlightened views on Climate Change and wouldn't be one for a scientific approach. Yet she came across as a rude know it all. In contrast when Healy Rae was making his infamous Dail speech Eamonn Ryan of the Green Party conducted himself with dignity and didn't appeal to the lowest common denominator of the tittering school girl behaviour.

    As MT stated in an earlier post tonight he wished Meteorology was as advanced as Astronomy (predicting eclipses etc). So really Evelyn isn't in a position to laugh and condescend until the Science evolves further.


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


    JCX BXC wrote: »
    While I don't disagree with the point, I'd like to point out that before the news starts, what do we have? The Angeles.

    It's not an argument for this forum JCX and i take your point.

    However i look on the Angelus as a moment of reflection for those of all faiths and none. But perhaps you are right and it's too associated with Catholicism.


  • Registered Users, Registered Users 2 Posts: 8,913 ✭✭✭Danno


    JCX BXC wrote: »
    While I don't disagree with the point, I'd like to point out that before the news starts, what do we have? The Angeles.

    With the risk of being rude by replying and de-railing this thread into a science V theology battle, I would say that this island's heritage is predominantly a christian one and that our nation's tradition should not be erased for the sakes of it. I am quite happy that RTE have taken the strongly Catholic tone away from the 90 sec broadcast to reflect a broader society whilst keeping with some semblance of tradition.

    We have a strong sense of history in this island, and this ought to be preserved outright, regardless of who it offends. If it offends anyone, there is Rosslare and they do sell one-way tickets without quibble. We have produced some amazing people as a nation that have inspired the world over, either because of, or in spite of, our culture and tradition. We must strive never to lose this facet, otherwise we lose the very foundation of who we are.


  • Registered Users, Registered Users 2 Posts: 18,228 ✭✭✭✭JCX BXC


    Danno wrote: »
    We have a strong sense of history in this island, and this ought to be preserved outright, regardless of who it offends. If it offends anyone, there is Rosslare and they do sell one-way tickets without quibble.

    But you just said "Exactly, it's very condescending and has no place in a publicly funded broadcast from a publicly funded organisation"

    Double standards?


  • Registered Users, Registered Users 2 Posts: 8,913 ✭✭✭Danno


    nagdefy wrote: »
    I think it was on the TV3 night show that she was giggling away at Danny Healy Rae's climate views. We all know Danny HR doesn't have the most enlightened views on Climate Change and wouldn't be one for a scientific approach. Yet she came across as a rude know it all. In contrast when Healy Rae was making his infamous Dail speech Eamonn Ryan of the Green Party conducted himself with dignity and didn't appeal to the lowest common denominator of the tittering school girl behaviour.

    As MT stated in an earlier post tonight he wished Meteorology was as advanced as Astronomy (predicting eclipses etc). So really Evelyn isn't in a position to laugh and condescend until the Science evolves further.

    Exactly, and I'd bet my bottom dollar that Evelyn takes her couple of foreign trips away to sunnier climes each year burning tons upon tons of fossil fuels jetting herself to her desired destination. The whole "do as I say, not as I do" attitude is very rude. Ditto for that Ryan fellow who has his papers chauffeured to Dail Eireann whilst "seen to be doing the good thing by taking the bus" via taxpayers money is sickening to see.


  • Registered Users, Registered Users 2 Posts: 8,913 ✭✭✭Danno


    JCX BXC wrote: »
    But you just said "Exactly, it's very condescending and has no place in a publicly funded broadcast from a publicly funded organisation"

    Double standards?

    No double standards at all... they can choose not to lecture in the first place. ;)


  • Registered Users, Registered Users 2 Posts: 5,778 ✭✭✭up for anything


    nagdefy wrote: »
    We all know Danny HR doesn't have the most enlightened views on Climate Change and wouldn't be one for a scientific approach.

    "“God above is in charge of the weather and we here can’t do anything about it,” he told the Dáil during a debate on climate change on Wednesday."
    Danno wrote: »
    With the risk of being rude by replying and de-railing this thread into a science V theology battle, I would say that this island's heritage is predominantly a christian one and that our nation's tradition should not be erased for the sakes of it. I am quite happy that RTE have taken the strongly Catholic tone away from the 90 sec broadcast to reflect a broader society whilst keeping with some semblance of tradition.

    We have a strong sense of history in this island, and this ought to be preserved outright, regardless of who it offends. If it offends anyone, there is Rosslare and they do sell one-way tickets without quibble. We have produced some amazing people as a nation that have inspired the world over, either because of, or in spite of, our culture and tradition. We must strive never to lose this facet, otherwise we lose the very foundation of who we are.

    I never thought I'd see this in the Weather forum. It better belongs in a berate the refugees thread in After Hours.
    Danno wrote: »
    Exactly, and I'd bet my bottom dollar that Evelyn takes her couple of foreign trips away to sunnier climes each year burning tons upon tons of fossil fuels jetting her butty to her desired destination. The whole "do as I say, not as I do" attitude is very rude. Ditto for that Ryan fellow who has his papers chauffeured to Dail Eireann whilst "seen to be doing the good thing by taking the bus" via taxpayers money is sickening to see.

    Maybe you ought to take your bets to Vegas and stop taking pot shots at people unless you have PROOF. As for 'her butty' - what kind of a child are you?


  • Registered Users, Registered Users 2 Posts: 8,219 ✭✭✭Gaoth Laidir


    So anyway, yeah, I reckon on average, this winter will be markedly colder than both last summer and next.


  • Registered Users, Registered Users 2 Posts: 11,882 ✭✭✭✭Rock Lesnar


    I remember when this was a weather forum, they were good times, good times indeed


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  • Registered Users, Registered Users 2 Posts: 8,913 ✭✭✭Danno


    "“...stop taking pot shots at people unless you have PROOF...

    I'm not taking pot shots at anyone, just alluding to the ways that those who lecture about climate change, advocate for huge expenses to be levied on everyone in the land and yet continue to live out a lifestyle that contradicts their lecturing. Apologies if it appeared as a direct pot shot at Evelyn Cusack.

    There are plenty of people up and down the country who cannot afford to heat their homes sufficiently because of the taxes levied on fuel that are brought about by the government who have the ear of those lecturing about climate change. This kinda stuff pisses people off no end cause they see through it as yet another means for the government to siphon their hard earned cash.


  • Registered Users, Registered Users 2 Posts: 5,718 ✭✭✭giveitholly


    This thread needs some weather


  • Registered Users Posts: 26 ferretr33


    Can we get back to the weather weather please


  • Registered Users, Registered Users 2 Posts: 18,228 ✭✭✭✭JCX BXC


    To be fair, we are talking about the weather on some edge, and as it's not winter yet it's not like there's current reports or anything to be had.

    Anyway, I'm of the opinion of either join in the discussion or don't complain ;)


  • Registered Users, Registered Users 2 Posts: 22,597 ✭✭✭✭Akrasia


    Long range weather forecasting is a bit like trying to predict which sports team will win your competition of choice at the start of a long season

    You can look at the team sheets and compare the players and managers against each other and think that the better team on paper will win more games on average than the team of young try hards

    But then the matches are played and there are lucky goals, red cards, injuries, managers get sacked and teams get into a bad run of form, referees make mistakes, players score own goals, keepers drop the ball, playmakers hit a bad run of form, dressing room spats happen to disrupt the teams performance...

    And all of a sudden you have Leicester City or Connacht coming from nowhere and winning the league.

    All the experts who made their predictions at the start of the season all had good and justifiable reasons backed up with analysis and statistics, but sports, as well as weather are chaotic and predictions cannot account for the seemingly random events that can change the course of history.


  • Registered Users, Registered Users 2 Posts: 18,228 ✭✭✭✭JCX BXC


    It's quite funny that Met Eireann say it's not possible to forecast beyond 10 days, when their UK counterparts UKMO forecast up to 30 days ahead.


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


    "“God above is in charge of the weather and we here can’t do anything about it,” he told the Dáil during a debate on climate change on Wednesday."

    I never got the hilarity which greeted that statement on the weather last year. It never meant more to me than we have no control over the weather, it's something beyond our control.

    When people make comments on 'the supreme being', or karma and the universe, or universal energy like Reikki no one laughs at all!

    Anyway off topic but it's not surprising that speaking of LRFs led us all in tangents. At any rate I hope it's a nice wintry winter:)


  • Registered Users, Registered Users 2 Posts: 6,238 ✭✭✭Oneiric 3



    I found the pressure analysis above to be interesting, I suspect it may have to do with background pressure variations in the atmosphere caused by interactions between the Sun and sources of gravitational energy. Although the curves look quite pronounced, Oneiric would probably agree that differences of 5 to 10 mb are not a large component of the overall variability (which is closer to 50-100 mb). So if this were the only factor at work, we would just see a slight uptick in storminess around those times of lower pressures.

    I analyzed some pressure stats for Malin Head over a roughly similar period and found significant troughs (10-15 mb) around the times of new and full moons in December and January. This tendency fades out in February and March. Some time I might start a thread about some research I've done into the dynamics that might be causing those oscillations, but even 10-15 mb, while it may sound significant, is a rather small portion of the overall variability.

    Indeed M.T, but keep in mind that the data I used is not only averaged over the period of 30 years, but also 'smoothed' out over a running period of 7 days, which I did, not only to mark out notable trends in the data, but also to make the graph more palatable to the eye. So the range in the case is not so important (if it can be deemed important to begin with!) as the general trends.

    New Moon



  • Registered Users, Registered Users 2 Posts: 6,238 ✭✭✭Oneiric 3


    nagdefy wrote: »
    I think it was on the TV3 night show that she was giggling away at Danny Healy Rae's climate views. We all know Danny HR doesn't have the most enlightened views on Climate Change and wouldn't be one for a scientific approach. Yet she came across as a rude know it all..

    I wager though, that Danny Healy Rae has a far more enlightened view on the intricacies of people and society in general than Evelyn would have; after all, that is why he is doing what he is doing. I think when push comes to shove, he probably has done more to help out ordinary, everyday people who have to deal with real world problems than she ever has.

    New Moon



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


    Oneiric 3 wrote: »
    I wager though, that Danny Healy Rae has a far more enlightened view on the intricacies of people and society in general than Evelyn would have; after all, that is why he is doing what he is doing.

    I'd very much agree:D


  • Closed Accounts Posts: 1,613 ✭✭✭server down


    Oneiric 3 wrote: »
    Indeed M.T, but keep in mind that the data I used is not only averaged over the period of 30 years, but also 'smoothed' out over a running period of 7 days, which I did, not only to mark out notable trends in the data, but also to make the graph more palatable to the eye. So the range in the case is not so important (if it can be deemed important to begin with!) as the general trends.

    Anecdotally your trend makes sense to me. I rarely remember storms in the early Dec buildup to Christmas, storms just before Christmas and before and over the new year seem common (there are lots of reports of people finding it hard to get back to work in my memory). and then when the kids go back that seems to quiten down again.

    Edit: of course that could be the news cycle. A storm on dec 30-jan 2nd is more disruptive of travel than one on jan 12th


  • Registered Users, Registered Users 2 Posts: 13,666 ✭✭✭✭sryanbruen


    Same here ^, only a few storms come to my mind through the early December period. Namely Bawbag in 2011, Desmond in 2015 and North Sea tidal surge in 2013 off the back of my head.


  • Closed Accounts Posts: 1,613 ✭✭✭server down


    sryanbruen wrote: »
    Same here ^, only a few storms come to my mind through the early December period. Namely Bawbag in 2011, Desmond in 2015 and North Sea tidal surge in 2013 off the back of my head.

    I was going to say 2015/2016 aside. That winter was crazy with storms.


  • Registered Users, Registered Users 2 Posts: 14,585 ✭✭✭✭M.T. Cranium


    I would agree, there's a definite lack of major storms (in western Europe) in the first half of December compared to the second half and then the first half of January.

    It's not an absolute lack, however, there was a very severe storm around 8-9 Dec of 1886, and if the calendar had changed before 1752, the Daniel Defoe storm (1703) would also have fallen on the 8th of December (it was recorded on the 27th of November because Britain was still using the Julian calendar).

    These are not excluded times in other climate regions in the mid-latitudes so it would seem to be a function of the Atlantic circulation. Really cold air masses seem rare across far eastern Canada until well into December so that's probably the main reason why the jet stream remains rather bland, while December is too late in the season to get much stimulation from tropical remnants (some think the Defoe storm might have been a late season tropical remnant, all we know with any certainty about it was that it tracked roughly WSW-ENE across south Wales and central England -- it probably had a nasty backlash effect in Ireland but there are no records that I know of concerning its effects in Ireland).

    The pressure pattern that Oneiric3 shows for the recent past could be studied over a hundred and fifty years (almost) by using the wetterzentrale archives. Probably just one pressure reading taken at one location would be sufficient, so I might see if we could form a research communal effort, pick the location and have several people note down daily pressure readings from the maps for that location (Dec/Jan.Feb) then collate it into a study. It sounds daunting but you could probably do one winter in less than an hour.

    If I don't manage to get that going, I will see if I have some time this winter to do the data entry from 1871 when the maps begin, to whenever Oneiric's study began, think that was 1981. Then we can see if this effect is permanent or if it shows any tendency to shift with time over 150 years.

    If ten people were willing to take ten years and send me the data, we could get this done fairly fast. I could check the work at random to make sure no systematic errors were creeping in.


  • Registered Users, Registered Users 2 Posts: 6,238 ✭✭✭Oneiric 3


    I would agree, there's a definite lack of major storms (in western Europe) in the first half of December compared to the second half and then the first half of January.

    It's not an absolute lack, however, there was a very severe storm around 8-9 Dec of 1886, and if the calendar had changed before 1752, the Daniel Defoe storm (1703) would also have fallen on the 8th of December (it was recorded on the 27th of November because Britain was still using the Julian calendar).

    These are not excluded times in other climate regions in the mid-latitudes so it would seem to be a function of the Atlantic circulation. Really cold air masses seem rare across far eastern Canada until well into December so that's probably the main reason why the jet stream remains rather bland, while December is too late in the season to get much stimulation from tropical remnants (some think the Defoe storm might have been a late season tropical remnant, all we know with any certainty about it was that it tracked roughly WSW-ENE across south Wales and central England -- it probably had a nasty backlash effect in Ireland but there are no records that I know of concerning its effects in Ireland).

    The pressure pattern that Oneiric3 shows for the recent past could be studied over a hundred and fifty years (almost) by using the wetterzentrale archives. Probably just one pressure reading taken at one location would be sufficient, so I might see if we could form a research communal effort, pick the location and have several people note down daily pressure readings from the maps for that location (Dec/Jan.Feb) then collate it into a study. It sounds daunting but you could probably do one winter in less than an hour.

    If I don't manage to get that going, I will see if I have some time this winter to do the data entry from 1871 when the maps begin, to whenever Oneiric's study began, think that was 1981. Then we can see if this effect is permanent or if it shows any tendency to shift with time over 150 years.

    If ten people were willing to take ten years and send me the data, we could get this done fairly fast. I could check the work at random to make sure no systematic errors were creeping in.

    The data I used was extracted (about 5 years ago) from the ECMWF reanalysis project via grib extraction (ERA 40 + ERA Interim) and from 5 grid points located at the 5 various locations used in the original 'IMT' series.

    http://apps.ecmwf.int/datasets/

    The data goes back to 1957 only, and though the ERA - 20 does go back to January 1900, I can't seem extract data from them as I can the other two.


    What I will do later, if it is any use, is include all the data from 1957 up to 2010 and average it out as opposed to using just the latest 1981-2010 average.

    New Moon



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  • Registered Users, Registered Users 2 Posts: 13,666 ✭✭✭✭sryanbruen


    The AO is expected to go through the floor negative during mid-November :eek:. That kind of AO the GFS ensembles are picking up on at the end here on the chart are 2010 standards negative AO or blocking over the Arctic!

    VHPqtzI.gif


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


    sryanbruen wrote: »
    The AO is expected to go through the floor negative during mid-November :eek:. That kind of AO the GFS ensembles are picking up on at the end here on the chart are 2010 standards negative AO or blocking over the Arctic!

    VHPqtzI.gif

    Nice one! Tis the season to be hopeful!

    Send us down the polar vortex, tra la la la la la la la :)


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


    Let's just hope that if any blocking occurs it's not a week or 2 too early. I'd imagine blocking sending down a northerly or northeasterly around mid November may not be as potent as 10 to 14 days later in the season. In 2010 the first wintry 'onslaught' began around the 25th/26th November. We want proper cold to become established in the Arctic regions first. Not to waste a decent setup.

    A bit like getting a wonderful easterly in late March which would have been amazing two months earlier.


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


    gfs-1-384.png?12

    Roughly going by GFS FI projections it looks like they expect sufficient cooling to our north by the 22nd November.


  • Closed Accounts Posts: 1,544 ✭✭✭h7nlrp2v0g5u48


    If you believe anyone can forecast what our weather will be like next January santa Claus must be real too.
    I guess your not an avid reader or contributer to this thread because if you were you would not have posted the above.


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