Historic Pacific Warmth Set to Shape US Winter Weather

Far out in the tropical Pacific, ocean temperatures are running well above normal, signaling the arrival of an El Niño event that NOAA predicts could be historic. This massive pool of warm water heats the air above it, triggering thunderstorms and altering global air circulation patterns like the jet stream. During a strong El Niño, the jet stream typically shifts south to carry more storms across the southern United States, while limiting bitter Arctic air in the north. NOAA's winter outlook favors wetter-than-average conditions in the South and warmer temperatures across much of the northern US and Alaska. While seasonal outlooks reflect broad trends rather than daily forecasts, communities in the South are advised to prepare for potential heavy rains and flooding. Meanwhile, northern regions may experience slippery roads from freezing rain and slush rather than steady snow.