Snow prediction accuracy thread

Discussion in 'Weather' started by Jellybeans1000, Aug 4, 2017.

  1. Jellybeans1000

    Jellybeans1000 Dedicated Member
    Season Pass Gold

    Joined:
    Aug 24, 2015
    Messages:
    3,547
    Likes Received:
    2,706
    So this kinda explains it.
    An analysis of snow predictions from models, commercial forecasters and the government agencies. Just snow depths compared to each other. The brainchild of @The Plowking.

    This is the snow forecast according to the respective forecasters and models, for the 11-12 August period.
    [​IMG]
    Will fill in other parts of the table as we go...

    Please no snow predictions in this thread, keep them to the respective thread or BBQ.
    All chit chat and other talk to BBQ.
    Treat this as a recordbook to look at how the different forecasters perform.
    Over time, you could analyse the data and pick better forecasters for different types of events, etc.
    But this isn't a snow prediction thread, just a snow depth forecast analysis thread.

    Lets see how this goes...
     
  2. POW_hungry

    POW_hungry Part of the Furniture
    Season Pass Gold

    Joined:
    May 28, 2000
    Messages:
    10,757
    Likes Received:
    6,529
    What locale are you basing model data on? Major resort averages?
     
    Jellybeans1000 likes this.
  3. Jellybeans1000

    Jellybeans1000 Dedicated Member
    Season Pass Gold

    Joined:
    Aug 24, 2015
    Messages:
    3,547
    Likes Received:
    2,706
    Was wondering when somebody was going to ask...
    Jane: Her call
    Grasshopper: His call
    Frog: His call
    BOM: Based on Perisher
    Yr.no: Based on Perisher
    Model output: Based on NSW Main Range/Perisher/Thredbo area.

    P.S. If anyone should be added, just say.
     
    The Plowking and POW_hungry like this.
  4. Rat trap bindings

    Rat trap bindings New Member
    Season Pass Gold

    Joined:
    Jul 17, 2017
    Messages:
    45
    Likes Received:
    59
    Great thread idea!
    I'd like to throw into the ring snow-forecast.com as it is a worldwide prediction service with lots of info so for the period at Perisher they are saying 3cm. What effect though will the 80k wind prediction have I wonder?
     
    Jellybeans1000 likes this.
  5. Kelpieboy

    Kelpieboy Dedicated Member

    Joined:
    Jun 27, 2015
    Messages:
    1,128
    Likes Received:
    1,064
    I think CC will be disappointed he hasn't been included ;)
     
  6. POW_hungry

    POW_hungry Part of the Furniture
    Season Pass Gold

    Joined:
    May 28, 2000
    Messages:
    10,757
    Likes Received:
    6,529
    It's GFS, so no need to complicate the anaylsis IMO...
     
    Claude Cat and Jellybeans1000 like this.
  7. nfip

    nfip Part of the Furniture
    Season Pass Gold

    Joined:
    Jul 24, 2006
    Messages:
    10,961
    Likes Received:
    7,608
    Great thread.
    Worth that we add AXR to the table pls. ?
    Or is it same as BOM you have included.
    It seems to have been on the money , at least in the 3 day window I accept , where others have been not so.
    Yes it is one of my go to
     
    The Plowking likes this.
  8. Belly

    Belly Addicted Member
    Season Pass Gold

    Joined:
    Oct 22, 2003
    Messages:
    5,822
    Likes Received:
    1,299
    Great idea. But a few surfers have posted here, and I can't help but think of the wave size scale debate threads on surf forums.

    Key considerations for mine are; where will the measurements be taken (location altitude aspect etc), and when measuring over multiple days will the total 24hour reported numbers be added (best indicator of unsettled IMO) or will it be the net base change from the start date to the finish date?
     
    W0nkey D0nkey and nfip like this.
  9. Rat trap bindings

    Rat trap bindings New Member
    Season Pass Gold

    Joined:
    Jul 17, 2017
    Messages:
    45
    Likes Received:
    59
    If it's GFS then why the prediction of 3cm that is more in line with Jane and The Frog..? Big difference between the raw GFS at 5 to 10cm. Surely the interest will be in the punter with out the skills of deep analysis like me that would like to see what the easy understood report accuracy is?
     
  10. POW_hungry

    POW_hungry Part of the Furniture
    Season Pass Gold

    Joined:
    May 28, 2000
    Messages:
    10,757
    Likes Received:
    6,529
    It is GFS as published on their site:
    http://www.snow-forecast.com/pages/faq#model

    In answer to your question, I don't know the locale/model run you have highlighted in that screenshot... GFS updates 4 times a day.

    This is another reason why Snow-Forecast shouldn't be included, it's NOT a reliable resource IMO - they don't publish the run timestamp (only their 'publish date') so God only knows when the data is from. Could be out of date for all we know.
     
  11. The Plowking

    The Plowking Part of the Furniture
    Season Pass Gold

    Joined:
    Aug 15, 2000
    Messages:
    14,337
    Likes Received:
    6,123
    Think 7 Days is easier

    11th August
    At 7 days
    GFS
    At 4 days

    11th August
    At 7 days
    AXSG
    At 4 days


    EC someone else, I dont subscribe to weatherzone and think it best we keep the same...pretty pictures...

    Will edit dates as per the op.
     

    Attached Files:

    #11 The Plowking, Aug 5, 2017
    Last edited: Aug 7, 2017
    Majikthise likes this.
  12. Jellybeans1000

    Jellybeans1000 Dedicated Member
    Season Pass Gold

    Joined:
    Aug 24, 2015
    Messages:
    3,547
    Likes Received:
    2,706
    EC...
     
    The Plowking likes this.
  13. Jellybeans1000

    Jellybeans1000 Dedicated Member
    Season Pass Gold

    Joined:
    Aug 24, 2015
    Messages:
    3,547
    Likes Received:
    2,706
    7 days will probably be easier as it aligns with AXS...

    AXS R and G are similar, will include them as one.
    BOM category details their Perisher (human) forecast.

    As I am using Perisher forecasts, I will use Perisher's 24 hour snow depths and stack them together within the particular event. I know Perisher's snow reporting isn't great, but it's the easiest option for me.

    As for snow-forecast.com, It is GFS with topography dressage.
    This. @Rat trap bindings No one is trying to be rude. I will think about adding snow-forecast.com, but I probably won't.

    And can we please stop the chit chat now. Just the snow predictions table and the model images from that particular day. Any additions or questions? Please send them via PM or take it to BBQ. All other chit chat to BBQ. Thanks all.
     
    SnowBound and The Plowking like this.
  14. The Plowking

    The Plowking Part of the Furniture
    Season Pass Gold

    Joined:
    Aug 15, 2000
    Messages:
    14,337
    Likes Received:
    6,123
    @Claude Cat
    Thread clean please!

    Relevant posts are
    #1
    #12
    #13

    @Jellybeans1000
    Perhaps edit first post explanation?
    And we're at 4 days...
     
    #14 The Plowking, Aug 7, 2017
    Last edited: Aug 7, 2017
  15. Jellybeans1000

    Jellybeans1000 Dedicated Member
    Season Pass Gold

    Joined:
    Aug 24, 2015
    Messages:
    3,547
    Likes Received:
    2,706
    [​IMG]
    3 day forecast...

    Model overview:



     
    Majikthise and The Plowking like this.
  16. Jellybeans1000

    Jellybeans1000 Dedicated Member
    Season Pass Gold

    Joined:
    Aug 24, 2015
    Messages:
    3,547
    Likes Received:
    2,706
    [​IMG]
    Next system, Tuesday to Friday next week. Leaving Saturday and beyond for the fairies...



    Most of the snow is forecast to fall on the Thursday and Friday...
     
  17. Claude Cat

    Claude Cat Gone Fishing
    Moderator Season Pass Gold

    Joined:
    Jul 6, 2001
    Messages:
    92,124
    Likes Received:
    28,788
    IMO one tendency I've noticed is that systems tend to slip in dates. Eg the system ends up delivering a day later than when it first appears say at 196 (or more) hours.
     
  18. Jellybeans1000

    Jellybeans1000 Dedicated Member
    Season Pass Gold

    Joined:
    Aug 24, 2015
    Messages:
    3,547
    Likes Received:
    2,706
    Hence why I am doing it. To see what happens to a system and get it recorded in a easy to read format. It does get tricky when it does slip. That's why I have given it such a wide range. If it merges with the next weekend system, I will merge the two records :)
     
    The Plowking and Claude Cat like this.
  19. Jellybeans1000

    Jellybeans1000 Dedicated Member
    Season Pass Gold

    Joined:
    Aug 24, 2015
    Messages:
    3,547
    Likes Received:
    2,706
    So our first results are in.
    [​IMG]
    In summary, the models and the Frog got it right.
    The other 'people' forecasters got a little bit over.
    Synoptic of system below...
     
    D_Dog, SnowBound and The Plowking like this.
  20. Jellybeans1000

    Jellybeans1000 Dedicated Member
    Season Pass Gold

    Joined:
    Aug 24, 2015
    Messages:
    3,547
    Likes Received:
    2,706
    And for the coming system...
    [​IMG]
    Predictive synoptics:


    Edit: I added in Saturday, because it was part of the system.
     
    The Plowking likes this.
  21. Rush

    Rush Pool Room
    Season Pass Gold

    Joined:
    Jul 26, 2000
    Messages:
    42,231
    Likes Received:
    9,833
    Best thread ever.
     
  22. Jellybeans1000

    Jellybeans1000 Dedicated Member
    Season Pass Gold

    Joined:
    Aug 24, 2015
    Messages:
    3,547
    Likes Received:
    2,706
    [​IMG]
    I did this Tuesday night, just forgot to hit the upload button....

    You might notice some changes, EC and yr.no have been merged, thanks to a revelation of mine.
    And I have added in WZ snow forecasts.

    Next update: Tomorrow Night
     
    nickxylophone and The Plowking like this.
  23. Jellybeans1000

    Jellybeans1000 Dedicated Member
    Season Pass Gold

    Joined:
    Aug 24, 2015
    Messages:
    3,547
    Likes Received:
    2,706
    [​IMG]
    The results from last week's system.

     
    Bloke and D_Dog like this.
  24. Jellybeans1000

    Jellybeans1000 Dedicated Member
    Season Pass Gold

    Joined:
    Aug 24, 2015
    Messages:
    3,547
    Likes Received:
    2,706
    [​IMG]
    Incoming two systems(Monday and Wednesday). I did this on Saturday, yet again I forgot to press post.
     
    The Plowking likes this.
  25. Jellybeans1000

    Jellybeans1000 Dedicated Member
    Season Pass Gold

    Joined:
    Aug 24, 2015
    Messages:
    3,547
    Likes Received:
    2,706
    ####
     

    Attached Files:

    #25 Jellybeans1000, Aug 21, 2017
    Last edited: Aug 31, 2017
    The Plowking likes this.
  26. Jellybeans1000

    Jellybeans1000 Dedicated Member
    Season Pass Gold

    Joined:
    Aug 24, 2015
    Messages:
    3,547
    Likes Received:
    2,706
    [​IMG]


    Latest system coming up....
     
    W0nkey D0nkey likes this.
  27. Nidecker

    Nidecker Dedicated Member
    Season Pass Gold

    Joined:
    Aug 5, 2009
    Messages:
    2,228
    Likes Received:
    973
    this thread could be really good :) But its missing something, I can't quite put my finger on it
     
  28. Jellybeans1000

    Jellybeans1000 Dedicated Member
    Season Pass Gold

    Joined:
    Aug 24, 2015
    Messages:
    3,547
    Likes Received:
    2,706
    What would that be? Always up for improvements:)
     
  29. Wardy

    Wardy Well-Known Member

    Joined:
    Jun 7, 2010
    Messages:
    958
    Likes Received:
    354
    It's tops. What were the results for the last two August systems...?
     
  30. Majikthise

    Majikthise Sage
    Moderator Season Pass Gold

    Joined:
    Jan 1, 1970
    Messages:
    27,238
    Likes Received:
    8,220
    Needs some points system to build a league table... ;)
     
  31. Jellybeans1000

    Jellybeans1000 Dedicated Member
    Season Pass Gold

    Joined:
    Aug 24, 2015
    Messages:
    3,547
    Likes Received:
    2,706
    [​IMG]
    Results for the earlier system.
    I didn't keep going with the other one, because I was too busy skiing.
     
    Wardy and The Plowking like this.
  32. Jellybeans1000

    Jellybeans1000 Dedicated Member
    Season Pass Gold

    Joined:
    Aug 24, 2015
    Messages:
    3,547
    Likes Received:
    2,706
    Will do, when it finishes for the season.
     
  33. Nidecker

    Nidecker Dedicated Member
    Season Pass Gold

    Joined:
    Aug 5, 2009
    Messages:
    2,228
    Likes Received:
    973
    Thats the improvement I was looking for. :) I was being a little tongue in cheek, we all appreciate the time and effort many of you guys put into the weather thread .....
     
    Wardy and Jellybeans1000 like this.
  34. Jellybeans1000

    Jellybeans1000 Dedicated Member
    Season Pass Gold

    Joined:
    Aug 24, 2015
    Messages:
    3,547
    Likes Received:
    2,706
    That's fine. I just didn't press the post button on that one.
     
    Nidecker likes this.
  35. Jellybeans1000

    Jellybeans1000 Dedicated Member
    Season Pass Gold

    Joined:
    Aug 24, 2015
    Messages:
    3,547
    Likes Received:
    2,706
    [​IMG]
    This would be the current system....
    Taken Monday night, Saturday night and This morning. My timing be very off, but changing systems do that.
     
    Ozgirl likes this.
  36. Jellybeans1000

    Jellybeans1000 Dedicated Member
    Season Pass Gold

    Joined:
    Aug 24, 2015
    Messages:
    3,547
    Likes Received:
    2,706
    [​IMG]
    Current system.
    Previous system (BOO3) results out tomorrow
     
    The Plowking likes this.
  37. Jellybeans1000

    Jellybeans1000 Dedicated Member
    Season Pass Gold

    Joined:
    Aug 24, 2015
    Messages:
    3,547
    Likes Received:
    2,706
    BOO3 results.
    [​IMG]
    So I added up all the reported snowfall totals at Perisher and Thredbo, and Falls for balance.
    It was really big at Perisher as you may know.
     
    #37 Jellybeans1000, Sep 14, 2017
    Last edited: Sep 15, 2017
    rime noreason and Ian like this.
  38. The Plowking

    The Plowking Part of the Furniture
    Season Pass Gold

    Joined:
    Aug 15, 2000
    Messages:
    14,337
    Likes Received:
    6,123
    Absolutely unconvinced re perisher numbers.
     
    Alfred14 likes this.
  39. Jellybeans1000

    Jellybeans1000 Dedicated Member
    Season Pass Gold

    Joined:
    Aug 24, 2015
    Messages:
    3,547
    Likes Received:
    2,706
    Well that's the only data I got. Spencer's Creek unfortunately doesn't come in nice daily increments.
     
    The Plowking likes this.
  40. Undies

    Undies Part of the Furniture
    Season Pass Gold

    Joined:
    May 15, 2002
    Messages:
    16,837
    Likes Received:
    7,254
    Image no load. :(
     
  41. Jellybeans1000

    Jellybeans1000 Dedicated Member
    Season Pass Gold

    Joined:
    Aug 24, 2015
    Messages:
    3,547
    Likes Received:
    2,706
    Fixed :thumbs:
     
    Undies likes this.
  42. Undies

    Undies Part of the Furniture
    Season Pass Gold

    Joined:
    May 15, 2002
    Messages:
    16,837
    Likes Received:
    7,254
    166cm?!?!??!? Wowsers.
     
  43. Alfred14

    Alfred14 Active Member

    Joined:
    Sep 27, 2009
    Messages:
    633
    Likes Received:
    38
    Very surprising to see such a massive difference between Perisher and Falls, first it was 5cm increments now its measure the deepest wind drift in the resort.
     
    The Plowking likes this.
  44. The Plowking

    The Plowking Part of the Furniture
    Season Pass Gold

    Joined:
    Aug 15, 2000
    Messages:
    14,337
    Likes Received:
    6,123
    Just put an * after perisher.
    Maybe thredbo is a better option?
     
    Jellybeans1000 likes this.
  45. Jellybeans1000

    Jellybeans1000 Dedicated Member
    Season Pass Gold

    Joined:
    Aug 24, 2015
    Messages:
    3,547
    Likes Received:
    2,706
    Maybe. Thredbo has 133cm for their upper slopes for the period.
    I have asked the Perisher folk for some help.
     
    The Plowking likes this.
  46. Jellybeans1000

    Jellybeans1000 Dedicated Member
    Season Pass Gold

    Joined:
    Aug 24, 2015
    Messages:
    3,547
    Likes Received:
    2,706
    @The Plowking got info from the Perisher forums, that Perisher snow reporting has been pretty good this year. Strong winds would have blown a lot of snow from the ranges onto leeward aspects (much of Perisher). So 166cm probably didn't fall down as snow at that particular spot over that week, but there was 166cm there because of windloading plus proper snowfall. And I thought Buller's westerly wind situation was confusing....

    So I just put Thredbo's obs in to kind of gauge how much snow fell across the area a little better. And I will probably just use Perisher's numbers for the big tally at the end of the season.
     
  47. The Plowking

    The Plowking Part of the Furniture
    Season Pass Gold

    Joined:
    Aug 15, 2000
    Messages:
    14,337
    Likes Received:
    6,123
    If every big resort recorded snowfall as a leeward measurement they all would have got a similar amount.
    Spencers creek real data makes a mockery of Perishers measurements.
     
    Alfred14 likes this.
  48. The Plowking

    The Plowking Part of the Furniture
    Season Pass Gold

    Joined:
    Aug 15, 2000
    Messages:
    14,337
    Likes Received:
    6,123
    Didnt happen.
     
  49. Jellybeans1000

    Jellybeans1000 Dedicated Member
    Season Pass Gold

    Joined:
    Aug 24, 2015
    Messages:
    3,547
    Likes Received:
    2,706
    I was told that 147cm was the real number, and that sounds a little more realistic.
     
  50. The Plowking

    The Plowking Part of the Furniture
    Season Pass Gold

    Joined:
    Aug 15, 2000
    Messages:
    14,337
    Likes Received:
    6,123
    *leeward ;)
     
    Jellybeans1000 likes this.