Polar vortices, while not new, are becoming more severe due to rising Arctic temperatures. Evidence shows a common pattern in their frequency and intensity.
Weather tracker: Warm air engulfs parts of Argentina as winter temperatures soar
A plume of warm air will sink southwards from neighbouring Paraguay on Monday, lingering through Tuesday, before giving way to a cold front on Wednesday.
Update: Winter weather advisory affecting the Greater Lake Tahoe Area until Sunday midday
Travelers in the Greater Lake Tahoe Area should exercise caution due to significant snowfall and hazardous conditions from Friday night through Sunday morning.
