Tutorial La Nino and La Nina

Discussion in 'Alpine & Snow' started by Ian D, Aug 1, 2012.

  1. Ian D

    Ian D Pool Room Staff Member Administrator Moderator

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    Well actually it is El Niño and La Niña not La Nino and La Nina but it is amazing how many people search for la nino and la nina so I figured I would help them out as well!

    Basically these terms are used to describe ocean currents off the South American coast.

    El Niño relates to a warming of this current over normal and La Niña represents a cooling of this current. More generally it refers to the entire central and eastern tropical Pacific Ocean and is often referred to as ENSO (El Niño Southern Oscillation).

    The key thing for us in Australia and the snow fields is what does it do to the snowfalls here? Well that is not clear cut. Here are some AVERAGES for winter conditions in Australia.

    El Niño = reduced precipitation in Eastern Australia
    La Niña = increased precipitation in Eastern Australia

    El Niño = higher than average daytime temperatures in Eastern Australia
    La Niña = lower than average daytime temperatures in Eastern Austraila

    El Niño = normal or fractionally below average night time minimum temperatures in Eastern Australia
    La Niña = higher than average minimum night time temperatures in Eastern Australia

    The 12 big El Niño years are: 1914, 1940, 1941, 1946, 1965, 1972, 1977, 1982, 1991, 1994, 1997 and 2002.

    The 12 big La Niña years are: 1910, 1916, 1917, 1950, 1955, 1956, 1971, 1973, 1975, 1988, 1998 and 2010.

    If you check this against snowfall charts there is no clear correlation. Some seasons are cold and dry, others warm and wet and then sometimes we get it just right where it is cold and wet!

    The BOM offers a great resource if you are looking for more details.

    Comments and thoughts as always are welcome.
     
    #1 Ian D, Aug 1, 2012
    Last edited by a moderator: Dec 15, 2013
  2. Claude Cat

    Claude Cat On my bike Moderator Ski Pass: Platinum

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    As a gross generalisation neither strong El Niño or La Niña are good for snowfall in the in the Australian Alps.

    El Niño tends to be too dry - but cold.
    La Niña tends to be wet and warm.

    The best years for snow tend to be the neutral years (although this hasn't quite panned out this year at this point).
     
  3. Slushii

    Slushii Mostly missing in action... Ski Pass: Gold

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    Has anyone done correlations on El Nino/La Nina/Neutral years to snowfalls in any country (especially Australia?).
     
  4. Claude Cat

    Claude Cat On my bike Moderator Ski Pass: Platinum

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    Yes, Gerg has done this. Refer to SOI discussion

     
    #4 Claude Cat, Aug 1, 2012
    Last edited by a moderator: Dec 15, 2013
  5. Ian D

    Ian D Pool Room Staff Member Administrator Moderator

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    Excellent stuff, thanks Claude
     
  6. Claude Cat

    Claude Cat On my bike Moderator Ski Pass: Platinum

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    Current SOI can be seen here

    [​IMG]

    As you can see we're in distinctly neutral territory, having been in strong La Nina territory for the last two years.
     
    #6 Claude Cat, Aug 1, 2012
    Last edited by a moderator: Nov 12, 2013
  7. Sandy

    Sandy Dark Sith Lord of the Pool Room Moderator Ski Pass: Gold

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    For snow in Australia, between the 1950s and around the early 1980s, the worst values for SOI were larger than around +14( strong La Nina), and less than -13(Strong El Nino).

    In those days, the biggest seasons tended to have SOI values of around +6 to +12. It was colder in the 1950s-1960s, so the the increased precipitation during a strong La Nina meant more snow. These days, the higher SSTs mean that some of the better seasons are placed around +2 to +6, while values up towards +10 generally means a lot of rain.

    Also shifting are the other end, so that bad El Nino years more likely to be less than -16 or so.

    So all told, it's bit of a lottery, with values between +5 to -12 giving just about any result!!!!!
     
  8. Red_switch

    Red_switch Old n' Crusty Ski Pass: 30 Day

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    It's an even worse predictor for NZ, although SAM is a wee bit more useful for NZ.