The historic chill currently gripping the Eastern United States isn’t just a fleeting cold snap – it is the result of a “locked” atmospheric pattern that FOX Weather meteorologists warn could persist deep into February 2026.
The primary culprit behind this current “deep freeze” is a significant disruption of the polar vortex. Usually, this area of low pressure keeps frigid air bottled up over the Arctic. However, a combination of warm Arctic waters and heavy snow in Siberia has caused the vortex to “stretch” or elongate. Instead of spinning in a tight circle, the vortex has buckled, creating a direct conveyor belt of Arctic air flowing into the Eastern two-thirds of America. Experts note that once the polar vortex is disrupted in this way, it can take weeks for the circulation to stabilize, meaning the “floodgates” remain open for repeated cold surges.
The long-term pattern is being reinforced by high-latitude atmospheric blocking—specifically a “Greenland Block” (a negative phase of the North Atlantic Oscillation or -NAO). This high-pressure block acts like a dam in the atmosphere over the North Atlantic, preventing storms and cold air masses from progressing east. Because the air has nowhere to go, the record-shattering cold stalls over the East Coast, allowing temperatures to plummet day after day rather than moderating quickly.
While we are currently in a weak La Niña phase, which often favors warmer Southern winters, it is currently being overridden by a strongly positive Pacific North American (PNA) pattern. A massive ridge of high pressure is stuck over the Western U.S. (keeping it warm and dry), while a deep trough is carved out over the East. As snow cover builds in the Carolinas and Virginia, it reflects sunlight and cools the air further, helping to anchor the cold air mass in place.
The FOX Forecast Center says a brief reprieve or slight moderation in temperatures may occur mid-month, long-range models suggest this is not the end of winter. Forecasters are already tracking another potential cold blast in the second week of February, which could unleash another round of sub-zero temperatures and snow for the Northeast and Mid-Atlantic.