Overview

• Temperatures 30–50C above average in the Antarctic stratosphere have confirmed a rare sudden stratospheric warming, previously observed only in 2002 and 2019.
• The disrupted polar vortex is already altering surface patterns with dry westerlies, clearer skies and unseasonable heat along Australia’s east coast, while western Tasmania is more likely to see increased rainfall.
• The Bureau of Meteorology has downgraded its October outlook to no clear wet or dry signal, with short‑term guidance leaning toward warmer and drier conditions across much of eastern and southern Australia as the Southern Annular Mode trends less positive.
• Researchers note that such events can increase the chance of strong westerly bursts, gales and higher fire‑danger days in southern Australia even as recent wet conditions temper immediate bushfire risk.
• Competing climate drivers introduce uncertainty, with a negative Indian Ocean Dipole and a possible weak La Niña in play, and a smaller Antarctic ozone hole is a likely side effect of the stratospheric warming.