Overview
- The World Meteorological Organization puts the odds of a weak La Niña at about 55% for December to February, and NOAA’s Climate Prediction Center favors a transition back to neutral between January and March 2026.
- The U.S. National Weather Service warns of dangerous, potentially record cold from the Midwest to the Northeast, with subzero readings and wind chills affecting tens of millions and disrupting travel.
- Forecasters expect three successive Arctic intrusions tied to a displaced polar vortex, with AccuWeather highlighting sustained cold and Judah Cohen noting a stronger surge likely by mid‑December.
- Mexico’s SMN notes Frente Frío 18 will keep rain, strong winds and high‑terrain snow or ice in the north, while Frente Frío 19 arrives Sunday with a sharper temperature drop and a Gulf ‘Norte’ of 50–70 km/h.
- Seasonal guidance translated locally points to a drier, hotter stretch for parts of Argentina such as Rosario, with fewer substantial rainfall accumulations and elevated daytime temperatures.