A cold weather pattern affecting the Eastern United States is projected to continue throughout February.
FOX Weather meteorologists indicate this is due to a "locked" atmospheric pattern.
Key Atmospheric Factors
The primary cause of the current cold temperatures is a disruption of the polar vortex. This low-pressure area typically contains cold air over the Arctic. Warm Arctic waters and heavy snow in Siberia have contributed to the vortex elongating and diverting Arctic air into the Eastern U.S. The stabilization of this circulation can take weeks, allowing for repeated cold air surges.
High-latitude atmospheric blocking, specifically a "Greenland Block" (a negative phase of the North Atlantic Oscillation or -NAO), is reinforcing the pattern.
This high-pressure block over the North Atlantic prevents cold air masses from moving east, causing them to remain over the East Coast.
While a weak La Niña phase is active, it is currently overridden by a strongly positive Pacific North American (PNA) pattern. This involves a high-pressure ridge over the Western U.S. and a trough over the East. Increased snow cover in areas like the Carolinas and Virginia further cools the air and helps anchor the cold mass.
Forecast Outlook
The FOX Forecast Center anticipates a brief moderation in temperatures mid-month.
However, long-range models suggest the cold conditions are expected to continue.
Forecasters are monitoring another potential cold air event in the second week of February, which could bring additional sub-zero temperatures and snow to the Northeast and Mid-Atlantic regions.