A rare polar vortex split, the earliest in 70 years, threatens to unleash Arctic blasts across North America and Europe just as winter peaks.
Story Snapshot
- November 2025 Sudden Stratospheric Warming (SSW) split the vortex into two cores, creating direct Arctic air corridors.
- Prolonged cold projected for late January through February 2026 in US Midwest, East Coast, Canada, and northern Europe.
- Weak La Niña and easterly QBO amplify disruptions, challenging mild winter forecasts.
- Forecasts evolve: initial split predictions shift to stretching, with renewed cold risks mid-February.
- Impacts hit energy, travel, agriculture; historical analogs confirm severe outbreaks.
Polar Vortex Splits into Two Cores After Record-Early SSW
Late November 2025 marked the earliest major SSW in 70 years. Rapid temperature rises at the 10 mb level reversed zonal winds at 60°N, meeting major SSW criteria. Upward-propagating Rossby waves from Rockies and Himalayas disrupted the Polar Night Jet. The vortex split into cores over North America and Asia by December, opening Arctic air paths to mid-latitudes. This stratospheric-tropospheric coupling synchronized with weak La Niña and easterly QBO, boosting polar wave energy.
Historical Precedents Set Stage for Prolonged Cold
Analog years like 1958, 1968, and 2000 saw early splits trigger December-January freezes across continents. Recent SSWs in 2019 and 2021 brought later US snaps, but never this prematurely. The polar vortex, a low-pressure Arctic cyclone encircled by westerly winds, deforms when high-pressure anti-vortices intrude. Negative North Atlantic Oscillation reinforces Greenland blocking, locking cold patterns. These factors align to challenge seasonal models predicting mild winters.
Distinguishing this event, direct corridors from splits differ from typical displacements, funneling purer Arctic air southward. Common sense dictates preparation over denial; conservative values prioritize self-reliance amid unreliable forecasts from overreliant models.
Current Vortex Status Shows Distortion and Stretch
As of late January 2026, the vortex distorts into an oval at 10 mb, stretching toward North America rather than fully splitting per latest guidance. Arctic air plunges into central and eastern US, Canada, with a Nor’easter bombarding the East Coast. Southwest and Florida remain spared. Models signal mid-February SSW potential with over 50°C anomalies and blocking highs, renewing outbreaks. NOAA CPC notes neutral AO, with East US warming and West wetter.
Impacts Strike Midwest, Energy, and Travel Hardest
Short-term frigid temperatures and storms grip US Midwest and East for 5-14 days, hitting Minnesota severely. Northern Europe faces similar chills, while southern areas stay mild. Energy demand spikes raise heating costs; travel disruptions from power outages and blizzards mount. Agriculture risks crop damage; insurance braces for claims. Western snowpack benefits water supplies, easing drought—a silver lining in chaos.
Long-term, confirmed SSW could extend cold into late winter, straining unprepared regions. Social pressures build on vulnerable communities, underscoring need for robust infrastructure over government overreach.
Expert Views Clash on Split Versus Stretch
H24 Weather News calls it a “Polar Express” with split cores prolonging cold via negative NAO. Severe-weather.eu and Futura-Sciences predict true Arctic surges and February chaos. FOX Weather and CPC adopt conservative stance: stretching and displacement dominate, not full split, with AO neutralizing deep freezes. Sven Sundgaard warns Minnesota faces max stretched vortex risks. Rossby wave physics supports analogs’ intense cold predictions.
Sources:
Polar Vortex Collapse: Why February Is Shaping Up to Be Weather Chaotic
Polar Vortex Extreme Cold Spell East February Outlook
Polar Vortex is Stretched to the Max, Minnesota Could Get Hit Hard Again in February
