A renewed Antarctic outbreak is driving temperatures toward -20C (-4F) across southern Patagonia.Argentina's weather service has maintained its highest-level "red cold alert" across large areas, including Santa Cruz. Provincial Civil Protection expects lows down to -18C (0F) through Thursday, with isolated readings below -20C.The latest pulse follows several days of severe cold. El Calafate, Río Turbio and Gobernador Gregores all fell to around -17C (1F), while Río Gallegos reached -14.5C (6F), with a wind chill of -20.3C (-5F).A reported minimum of -16C (3F) circulated for Gobernador Gregores on July 27.Snow and ice have already forced Santa Cruz to suspend in-person classes across the entire province from July 27 through July 29, with frozen roads and sidewalks making travel increasingly hazardous.Farther north, "historic" snow buried El Bolsón, Río Negro, according to locals—a valley town at 420 m (1,380 ft).The Antarctic air mass is expected to hold through the remainder of the week, with further snow forecast. To the north, winter warmth currently dominates, but long-range models point to a sharp retreat come August: