AAO swings our way

The Antarctic Oscillation (AAO) is the strongest single effect in the statistical snow prediction model. AAO is a measure of how tightly the circumpolar flow blows around the pole. A loose pattern (negative AAO) means polar storms track further north and are more likely to bring us snow. The AAO tends to moves in regular short term cycles (weeks), but it also exhibits longer term swings with considerable coherence (months). The recent longer term trend has been strongly positive (bad), but in the latest update the 3-month average is back near zero, and appears headed negative. The June average AAO index was -0.27. We may yet see some decent falls this season.

3-month running mean AAO

2 comments to AAO swings our way

  • theflyingfordanlgia

    What is the main driver behind the AAO? Would melting sea ice (as a result of anthropogenic climate change) result in a positive AAO? Does the AAO have links to other teleconnections e.g. SOI, PDO and IOD? In addition to this, if a positive AAO has a negative effect on our snow seasons, why is it that 2000, the best season of the past decade, had a positive AAO??

    • Gerg

      A good question, to which I’ve yet to see a good answer. Looking…

      Oddly, despite correlations with our southern weather apparently at least as strong as ENSO, AAO seems to attract little attention in Australia. It gets much more in NZ.

Leave a Reply to theflyingfordanlgia Cancel reply

You can use these HTML tags

<a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>