Overview

• NOAA recorded stratospheric temperatures over Antarctica up to 50C above average from September 12–21, confirming a Sudden Stratospheric Warming that is uncommon in the Southern Hemisphere.
• The Bureau of Meteorology has downgraded spring expectations, with no clear wetter signal for October and short‑term modelling tilting drier and warmer for much of Australia as the Southern Annular Mode eases.
• Dry westerlies have dominated in recent weeks, clearing skies and driving unseasonable heat along the east coast, including Sydney averaging about 26C for maximums this week.
• Weatherzone expects the disrupted jet to pull cooler air toward southern states into early October, bringing more rain and westerlies in parts of Tasmania, Victoria, South Australia and Western Australia, with drier‑than‑average conditions in the east.
• BOM research led by Eun‑Pa Lim finds SSWs can outweigh IOD and ENSO influences in spring and early summer, increasing the likelihood of hot, dry and fire‑conducive weather in subtropical eastern Australia despite concurrent negative IOD and a possible weak La Niña.