Much of the snow arrived in August , May to July had just about no snow for those Aussie fields. Only in the last few weeks have we been seeing the deep southerlies on the weather charts for our region. Dunedin and Invercargill have had a lack of the usual sleet and snow events over winter.
Yes indeed, I agree, the problem I have with the way that article is written is that it says.....
The southern annular mode (Sam), which measures the strength of the vortex, has been at record highs in the past month, meaning the polar air has been locked around Antarctica.
....when it is clear that for our neighbours across the ditch, it hasn't been locked up, as you note when you mention deep southerlies. It might have been locked up so far as
NZ is concerned but the article infers much more than this.
I think it is clear that the Sam might be at records highs but it doesn't preclude polar air moving north.
Like the El Nino and La Nina events, it means certain weather patterns are more or less likely to occur, but never means there isn't a chance of exactly the opposite happening to what is meant to happen.