The first of multiple Arctic blasts expected this month brought record-low temperatures across the Midwest on Thursday, December 4, 2025, with reports of over 40 record lows for the day. More record lows are expected as the Arctic wave moves through the Northeast on Friday, December 5.
Heavy snow squalls are forecast to hit much of the U.S. Northeast through Thursday, December 4, 2025, with New York State and parts of New England expected to see the strongest impact. The snow squalls triggered by, and arctic surge will create dangerous travel conditions across key routes including the I-90 corridor.
The polar vortex is forecast to settle near Hudson Bay, sending repeated waves of Arctic air into the central and eastern U.S. during the first half of December 2025.
A sudden stratospheric warming event has begun, deforming the Polar Vortex and setting the stage for a colder start to winter across the United States, Canada, and Europe.
An arctic blast could be in forecast for the U.S. during December 2025, with a sudden stratospheric warming (SSW) being forecast to disrupt the polar vortex. This will result in a spill of arctic air across mid-latitudes and below average temperatures across the U.S.
An early stratospheric warming developing over the Arctic in late November 2025 is raising the likelihood of colder conditions and increased snowfall across parts of the United States, Canada, and possibly Europe in December.
An early-season stratospheric warming event is forecast to weaken the polar vortex in the coming weeks, potentially influencing winter 2025–26 weather across North America and Europe.
Forecast data indicate an early weakening and displacement of the stratospheric polar vortex over the Arctic in October 2025, as a developing high-pressure anomaly over Greenland interacts with the circulation earlier than usual, increasing the chances of colder air movement toward the mid-latitudes of North America and Europe.
A rare stratospheric warming event is disrupting the Antarctic polar vortex in September 2025, with forecasts suggesting wetter southern Australia, drier eastern Australia, and a higher chance of abnormally hot days.
A sudden stratospheric warming event is unfolding over Antarctica in early September 2025, rapidly weakening the southern polar vortex. Forecast models indicate potential downstream effects on the Northern Hemisphere jet stream, with implications for winter 2025/26 in the USA and Canada.
