A rare Super El Niño is building fast. See when it could start steering storms, unlocking Arctic air and shaping an early U.S ...

A fresh blast of Arctic air is poised to spill across a wide swath of the United States, and the latest polar vortex map makes clear which regions are most exposed. Forecast models show a sharp ...

Arctic air is expected to bring “near record cold” along with “dangerous wind chills” as it tracks south from the Northern High Plains on Friday, spreading into the Central Plains and Ohio Valley on ...

Two types of jet stream patterns seem to be causing persistent heat domes over Europe, with big questions for the future ...