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Winter 20/21 - General Discussion

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  • Registered Users Posts: 32,634 ✭✭✭✭Graces7


    NK76 wrote: »
    Hi All ...I've noticed the leaves browning and even falling already...seem to be lots of berries early this year...is this a sign of a cold winter ?

    Are there any winter predictions yet

    ❄☃️❄

    The blackberries here are around two weeks later than usual. And not as abundant or well fleshed out as too little sun.


  • Registered Users Posts: 32,634 ✭✭✭✭Graces7


    And my longing to make just ONE MORE SNOWMAN before I die stays with me! I suppose that if it does not snow then I get to live another year? Only just thought of that :eek:

    But what comes will come.


  • Registered Users Posts: 1,524 ✭✭✭SeaBreezes


    Graces7 wrote: »
    The blackberries here are around two weeks later than usual. And not as abundant or well fleshed out as too little sun.

    Agreed. Bad crop of berries here too this year.

    Regarding the clifden floods i do remember torrential rain and flooding like that in cork in 2009.

    Nov we were knee deep in crazy rainfall, Dec big freeze.
    Wonder if its a similar pattern.
    You may get your snow yet Graces :)

    Note: This is a pure wishcast based on 'feelings' no science behind it whatsoever..


  • Registered Users Posts: 32,634 ✭✭✭✭Graces7


    SeaBreezes wrote: »
    Agreed. Bad crop of berries here too this year.

    Regarding the clifden floods i do remember torrential rain and flooding like that in cork in 2009.

    Nov we were knee deep in crazy rainfall, Dec big freeze.
    Wonder if its a similar pattern.
    You may get your snow yet Graces :)

    Note: This is a pure wishcast based on 'feelings' no science behind it whatsoever..

    Love it!

    The last snowman I made was in Orkney where we had thick snow every winter. I made it too near the back window and it used to startle me..It lasted weeks

    This time it will be part way up the drive :D


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


    Looking at the weather the past few months, I noticed the wind coming from the north or northwest a lot. Seems like our weather is totally upside down, and I really think our seasons no longer match the weather we get.
    My prediction for this winter is that the Atlantic will dominate and we’ll have mild mucky weather. A few blasts of frost, but little to no snow.
    This is also not based on science just what I think.


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  • Moderators, Recreation & Hobbies Moderators, Sports Moderators Posts: 15,676 Mod ✭✭✭✭Tabnabs


    Huge crop of blackberries here on the east coast this year, have been ripe and ripening for over a month now. Two apple trees laden with fruit also. A bumper year for us.

    Will we have snow this winter? god no. It will be rain, 14 degrees at Christmas and the odd blast of a storm. It's Ireland...


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


    Teleconnections this far out don't mean much, but one thing people should be aware of is that in terms of Sea Surface Temperature analogs (that is, previous years in which the global SST anomaly resembled this year's so far), 2010 and 2017 have consistently shown up as the two strongest analogs. And as we all know, both of these years were followed by absolutely spectacular winter snowfalls.

    Unfortunately, 2013 has also consistently appeared as an analog, and we all remember what a disappointing Winter that was. Even so, there's clearly at least some potential there.

    Not saying this to get anyone's hopes up, just an observation! I've been keeping an eye on the SST analogs all year for the purposes of predicting the hurricane season and this has been a consistent feature since very early in the year.

    One thing to note is that horrible cold pool in the North Atlantic to our West, which did feature throughout summer 2017 but was noticeably absent from summer 2010. I have no idea if this has any basis in reality, but logic would denote that this makes any epic event this winter more likely to be backloaded a la 2017-18 as opposed to frontloaded a la 2010.

    One final observation is that the large warm pool in the North Central Pacific bears a strong resemblance to that of 2013, and it does concern me that this may provide the jet stream with a crap-ton of energy. But still too early to say.

    Thoughts?

    The current SSTA compared with the analog years:

    Current (last 30 days):

    1YDOi5H.png

    August 2017 (closest analog):

    LNSGXOr.png

    August 2010 (2nd closest analog):

    hUPJ9lu.png

    August 2013 (3rd closest analog):

    qu7m6Ne.png


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


    screamer wrote: »
    Looking at the weather the past few months, I noticed the wind coming from the north or northwest a lot. Seems like our weather is totally upside down, and I really think our seasons no longer match the weather we get.
    My prediction for this winter is that the Atlantic will dominate and we’ll have mild mucky weather. A few blasts of frost, but little to no snow.
    This is also not based on science just what I think.

    Unfortunately this is the most likely situation most winters, just as likely as a relatively cool and wet summer. However the past two winters were excessively mild even by Irish standards with last winter in particular an absolute train wreck for cold weather lovers not just in Ireland but also the UK and most of Europe including southern parts of Scandinavia. Last winter was dominated by an incredibly strong and dominant polar vortex which kept the cold locked up in the article circle throughout the winter and into the first half of Spring. Will the polar vortex be as strong again this year? Hopefully not, it will probably still be strong as usual but not to the same record breaking extent as last year.


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


    Teleconnections this far out don't mean much, but one thing people should be aware of is that in terms of Sea Surface Temperature analogs (that is, previous years in which the global SST anomaly resembled this year's so far), 2010 and 2017 have consistently shown up as the two strongest analogs. And as we all know, both of these years were followed by absolutely spectacular winter snowfalls.

    Unfortunately, 2013 has also consistently appeared as an analog, and we all remember what a disappointing Winter that was. Even so, there's clearly at least some potential there.

    Not saying this to get anyone's hopes up, just an observation! I've been keeping an eye on the SST analogs all year for the purposes of predicting the hurricane season and this has been a consistent feature since very early in the year.

    One thing to note is that horrible cold pool in the North Atlantic to our West, which did feature throughout summer 2017 but was noticeably absent from summer 2010. I have no idea if this has any basis in reality, but logic would denote that this makes any epic event this winter more likely to be backloaded a la 2017-18 as opposed to frontloaded a la 2010.

    One final observation is that the large warm pool in the North Central Pacific bears a strong resemblance to that of 2013, and it does concern me that this may provide the jet stream with a crap-ton of energy. But still too early to say.

    Thoughts?

    Like last year, my updates will be fewer and further between with no plans to issue a seasonal forecast as compared to pre-2019 years just due to loss of interest or life getting in the way. You're probably better off because I tend to waffle a lot :o

    However, every now and then, I will post an update on teleconnections or analogs that I feel could guide us through this annual rollercoaster.

    Firstly, yes good analogs there for North Atlantic SSTs. What I will say is that this is the most important factor to consider for winter. SST anomalies in both Nov 2018 and Nov 2019 were favourable of positive NAO, that's what we got. The latter year had a North Atlantic tripole (NAT) through the summer of 2019 and an extreme level of blocking corresponded with this around Greenland but this signal was well and truly gone by November. Nov 2017 was favourable of positive NAO too but that "cold blob" you speak of could have been associated with the rather unusual amount of cold zonality the season had. It wasn't a typical unsettled winter and the north had it very snowy overall in particular akin to the winter of 1983-84 which was known for its cold northwesterlies. These SSTs are not the be all and end all (what is with weather?) as shown by 2017's situation and in the exceptional mild winter of 1997-98, we did get a NAT with a negative NAO but we often got a "Sceuro High" (Scandinavian-Euro high) scenario with winds often from a southerly quarter. Let's see where the SSTs are by November.

    Secondly, we have a La Nina in development in the Pacific. Historically, La Ninas favour the earlier part of the winter to be colder with a higher chance of positive NAO later on. The reverse is true with El Ninos. If we get a strong event however of either, it sort of scuppers the chances of high latitude blocking developing - again speaking historically rather than scientifically. There was an interesting paper published late last year (see link below) of the impacts of ENSO on the MJO and the results for the North Atlantic Oscillation which of course is the index that reflects the pressure pattern in the North Atlantic. Researchers found that +NAO is strongly teleconnected during El Nino years with the opposite for La Nina years and SSW events more likely during La Nina years too which makes sense.

    The long range modelling suggests a weak to moderate La Nina is likely whilst a minority forecast a strong event. This is a matter of nowcasting and watch how the situation develops in the Pacific. If I were a betting man, I would say moderate at most with highest chance being a weak event much like 2017-18.

    https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2019GL084683

    Thirdly, this is a new thing I'm discussing because research confirmed this impacted the Northern Hemispheric winter pattern of 2019-20, however I never heard anyone mentioning before then so not sure what to make of it myself! I have linked another paper below discussing how the Indian Ocean Dipole (IOD) was a driver in the positive NAO phase of 2019-20.

    Key points made include: The El Nino-Southern Oscillation (ENSO) was in neutral state for much of the winter so believed to have had little impact. With the winter being well forecasted to incredible extents, there must have been a driver of some sorts that would strongly correlate with a very positive NAO. Using the observed SSTs in the Indian Ocean in November 2019, what happened was a Rossby wave originated in the Indian Ocean and propagated through the Pacific into the Atlantic. This wave train reduced the magnitude of the Aleutian cyclone which typically acts as a buffer to the development of the stratospheric polar vortex (SPV) but due to the reduction, this allowed the SPV to take off to anomalously strong levels.

    This year, the IOD is on the weak to negative side so likely to not have the same impacts as last year.

    https://rmets.onlinelibrary.wiley.com/doi/full/10.1002/asl.1005


  • Registered Users Posts: 1,480 ✭✭✭Hooter23


    We can stop having delusions of getting sun in summer...now we can start having delusions of getting snow in winter


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


    sryanbruen wrote: »
    Like last year, my updates will be fewer and further between with no plans to issue a seasonal forecast as compared to pre-2019 years just due to loss of interest or life getting in the way. You're probably better off because I tend to waffle a lot :o

    I think I speak for everyone here when I say

    Darth-Vader-No-Gif.gif
    However, every now and then, I will post an update on teleconnections or analogs that I feel could guide us through this annual rollercoaster.

    I think I speak for everyone here when I say:

    tenor.gif?itemid=4624104

    With that out of the way, fantastic and ridiculously informative post as always Sryan. If you think you waffle too much, just remember that you're frollicking amongst us weather nerds on this forum and as such no amount of waffle from an expert such as yourself can in any way be described as too much ;)

    I've never actually considered the IOD as a factor in Irish Winter or indeed Irish Weather generally, simply because teleconnections generally propagate from West to East with events diminishing in impact the further West one goes from the starting point. On the other hand, having literally only just begun to learn about upper atmospheric waves and VP anomalies this summer, it makes a lot of sense that the Indian Ocean could start a chain reaction as you describe, in much the same way as it's known to influence ENSO. The lack of a positive IOD has been widely commented on with regard to hurricane season in the Atlantic, as has the likelihood of a weak to moderate La Nina, so from the sound of things we could well be in with a chance of seeing something interesting this year - at the very least, it sounds like model watching will be far more interesting this Winter than it was last year, with only one or two interesting scenarios showing up even in FI if I remember correctly.

    It's interesting that you've mentioned a weak to moderate ENSO event giving us a better chance at wintry conditions than either extreme end of the scale - reminds me of the paradox in certain hormone or neurotransmitter medicines and dietary supplements in which the effects can completely reverse if one increases the dosage too much. It's amazing how often this occurs in nature, wherein too much of a usually X promoting factor can actually inhibit far more than too little of it.

    Remind me at what time of year one can begin to monitor the SPV for signs of how strong or weak it may end up establishing itself?

    And given your intention to step back from forecasting, feel like nominating a successor to create our Strat Watch thread? I'm still nowhere near knowledgeable enough to do it myself, the opening post would be horrifically lacking in details :D:D:D


  • Moderators, Business & Finance Moderators, Recreation & Hobbies Moderators Posts: 24,647 Mod ✭✭✭✭Loughc


    sryanbruen wrote: »
    Like last year, my updates will be fewer and further between with no plans to issue a seasonal forecast as compared to pre-2019 years just due to loss of interest or life getting in the way. You're probably better off because I tend to waffle a lot :o

    However, every now and then, I will post an update on teleconnections or analogs that I feel could guide us through this annual rollercoaster.

    Understandable mate. Personally I’m a big fan of your posts but life comes first. Thanks for all your posts and information to date.

    Bring on the emotion rollercoaster of winter 20/21!!


  • Registered Users Posts: 6,335 ✭✭✭SouthWesterly


    Tabnabs wrote: »
    Huge crop of blackberries here on the east coast this year, have been ripe and ripening for over a month now. Two apple trees laden with fruit also. A bumper year for us.

    Will we have snow this winter? god no. It will be rain, 14 degrees at Christmas and the odd blast of a storm. It's Ireland...

    Same in kerry. Berry's are ripening. Already got 3kg on Monday.


  • Registered Users Posts: 6,335 ✭✭✭SouthWesterly


    sryanbruen wrote: »
    Like last year, my updates will be fewer and further between with no plans to issue a seasonal forecast as compared to pre-2019 years just due to loss of interest or life getting in the way. You're probably better off because I tend to waffle a lot :o


    Let me be the first to say that if you're not willing to do the job you're not paid to do then you're fired from the job you don't have. :D

    I Always enjoy not understanding the techno babble


  • Registered Users Posts: 1,524 ✭✭✭SeaBreezes


    My Hopes are definately up after HatrickPatrick and Syran updates!!

    (Assuming i understood it correctly)

    Thank you both.


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


    When you give up on the weather the weather gives.

    I've given up on ever seeing a cold snowy Winter like 2010 ever again but who knows. Maybe this year.

    One thing that's almost a given now is that we will get lots of rain.


  • Registered Users Posts: 32,634 ✭✭✭✭Graces7


    About 2010?

    "Age and forgetfulness sweeten memory" applies. OK? OK!


  • Closed Accounts Posts: 544 ✭✭✭Hawthorn Tree


    I hope we get a bitterly cold winter with loads of snow.
    I am not sure exactly how I managed it but I have packed my shed with about 3 years of turf and logs. Stockpiling I guess.
    My stove will be hopping and I also plan to do a lot of winter hiking.


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


    So, just to recap here:
    Not saying this to get anyone's hopes up, just an observation!
    SeaBreezes wrote: »
    My Hopes are definately up after HatrickPatrick and Syran updates!!

    worldburn-top.jpg


  • Registered Users Posts: 1,813 ✭✭✭NickNickleby


    So, just to recap here:





    worldburn-top.jpg

    heheheh

    Too late. You've created a monster:)::pac::pac::pac:

    Now, where are those snow-shoes I bought in 2011??:eek:


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


    10 year anniversary this year.....could it happen again??! Hey, it's 2020! :D



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


    This likely won't be much an issue here as compared to Netweather but I thought I should mention it anyway.

    A weak stratospheric polar vortex in late autumn is a good starting point but rarely does it coincide with a season of consistently weak SPV, 2009-10 being such a year. Recent years have had the tendency to feature a weak SPV through the autumn period or a disconnection between the trop and strat before a big ramp up or reconnection by December or January. This was especially the case in 2016-17. The life span of the SPV is non-linear, every season has maximum and minimum spikes to various degrees.

    I used models like the CFSv2 in years such as 2018-19 (my most recent winter forecast) in helping to anticipate major sudden stratospheric warming (SSW) events at long ranges. The issue with this is the model has a negative bias with hindcasting zonal mean zonal winds at 60N 10hPa that might not necessarily reflect the actual forecast. Simon Lee has a great thread on this matter below.

    https://twitter.com/SimonLeeWx/status/1306929368288178176?s=20

    I felt confident on using this model to anticipate a major SSW of some kind during December 2018 or January 2019 due to a theory regarding increased risk of such when the QBO is transitioning from easterly to westerly. Fortunately, this indeed verified but the effects were very different from the major SSW event in February 2018 of course. The hindcast of the CFSv2 is again showing weak zonal mean zonal winds for the autumn into the winter period but not to be relied upon and I don't have any other factors like the QBO in 2018-19 to make me consider otherwise this time.

    To answer a question set forth by hatrickpatrick, I think the earliest the annual stratosphere watch thread should be created is late October. You or anybody else are obviously more than welcome to do so any time but that's just my opinion.

    Meanwhile, on the ENSO side of things, we are firmly into weak La Nina now and it's looking more like an East Pacific (EP) Nina at the moment. Models like Glosea5 and CanSIPS show the possibility of this La Nina strengthening to strong levels by the end of the year. As mentioned prior, strong ENSO events historically do not correlate well for high latitude blocking dominated winters in our part of the world though the analog record of such is small. I think the chances of a strong La Nina are low at the moment with moderate having the highest probability. La Nina events favour the earlier part of the winter to having an increased chance of -NAO whilst the latter part favours +NAO so La Nina winters tend to be more front-loaded although, especially with weak events, this link is weak with decent number of exceptions from the past.

    Anyway, I digress.


  • Registered Users Posts: 6,235 ✭✭✭Oneiric 3


    Fairly typical 'La Nina' pattern over the N. American continent:

    Nina_impacts_flat_620.png

    which would suggest that explosive lows would easier develop of the eastern seaboard, but which really means nothing for us as 1. this could amplify high pressure zone over the central or NE Atlantic or, just keep the pattern flat and stormy over us, with the latter pattern slightly more likely if the La Nina remains in weak state.

    New Moon



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


    And to simplify what the above showed, most of the negative Arctic Oscillation / North Atlantic Oscillation combo (which indicates blocking in the high latitudes and cold air displaced into the mid latitudes like Ireland) winters have been associated with cool ENSO or La Nina events since 1990 as compared to El Nino.

    The pattern of the Octobers preceding these La Nina winters bears a striking resemblance to the projected synoptic profile across the Northern Hemisphere in late September / early October 2020 with including, but not limited to, blocking high pressure over the Urals and a corresponding trough near or over Ireland.

    The last tweet shows the 500mb height anomaly for the following November/December which both feature Greenland blocking and a southerly tracking jet stream. This is an overall average for the analog years and of course, extreme years like 2010 will skew things somewhat but interesting nonetheless and each of the years featured high latitude blocking at some point through their respective months.

    All food for thought and for fun, nothing more, nothing less.


  • Registered Users Posts: 820 ✭✭✭lapua20grain




  • Registered Users Posts: 1,524 ✭✭✭SeaBreezes




  • Registered Users Posts: 32,634 ✭✭✭✭Graces7


    Memories keep coming of my Orkney decade. Snow was part of every winter at some stage. But we were well equipped, not like the disruption in less experienced places. My home help would arrive with the shopping on the family tractor in two feet of snow.

    The island lorry ( rubbish collection etc) had a snowplough attachment. One year ( and I could see the lane from my door, but, thankfully, not hear the language..) it got stuck in the snow and had to be pulled out by a tractor....

    Watching my hens emerge into the snow, and be horrified to LOSE THEIR FEET! They have such expressive faces.

    " Ah yes, I remember it well.!"


  • Registered Users Posts: 32,634 ✭✭✭✭Graces7


    There was one week when the power failed on the whole island; there was thick snow on the ground..

    Romantic soul that I am, I stood at my front door in the moonlight, gazing at the silent expanses of white, dreaming of the "old days" when no one had electricity and life was a balancing act.... Then my practicai streak reminded me that there was a freezer and cupboards full of food behind me and that thankfully we will never know that kind of dire poverty again.

    But it was so utterly lovely, that snow silence. Whiteness in the moonlight.

    Snow seems to do that; take us back to "times long past"; maybe as it is blessedly rare we romanticise it? It is an adventure! And the utter silence it instils, So you hold your breath.,

    In those Orkney years I saw the reality of annual snow. The last snowman I made was there; I made it too near the back window and it used to make me jump as I thought someone was out there!

    If we get snow , I will put a large snowman on guard on the drive!

    Well, we can dream ..How about a thread on snow dreams! Later I mean..We have the autumn gales to get through first...


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  • Registered Users Posts: 1,960 ✭✭✭mcburns07


    I wasn't aware that snow was a common thing in Orkney, I know it's quite far north but it's surprising considering it's in a small island.


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