A spring of Sam (Southern Annular Mode) and La Nina summer?

5 September 2022

While there’s a slim chance regions of Australia may yet be spared a third consecutive wet, rainy, La Niña weather event this summer, the outlook for spring is not so promising.

The Bureau of Meteorology advised last week parts of eastern Australian can expect higher than usual rainfalls, thanks to another meteorological phenomenon, a positive Southern Annular Mode, or Sam, for short:

Further, Dr Bettio said a positive Southern Annular Mode (SAM) is also likely, which pushes weather systems south, bringing wetter easterly winds to NSW and fewer cold fronts to western Tasmania. Dr Bettio said parts of Western Australia and western Tasmania are likely to experience below average rainfall this spring. Almost all of Australia is likely to experience warmer than average nights, while cooler days are likely for large parts of the mainland except the tropical north.