Negative Southern Annular Mode develops, bringing snow, storms and colder conditions to southern Australia
A negative Southern Annular Mode (SAM) developed over the Southern Hemisphere on July 18, 2026, triggering a sharp shift in Australia’s winter weather. The change is expected to push cold fronts farther north through the remainder of July, bringing heavy rain, damaging winds, hail and low-level snow to Tasmania while leaving much of eastern New South Wales dry and unusually mild, according to Weatherzone meteorologist Ben Domensino. Forecast models indicate the negative phase is likely to persist for the rest of the month.
