Definition
A mass of very cold, dry, stable air that forms over the snow- and ice-covered regions of the Arctic and moves southward into mid-latitudes, often producing sharp drops in temperature and clear, dry weather along its leading edge.
Plain English
A large body of extremely cold, dry air that builds up over the far north and slides south, bringing sudden cold snaps and usually clear skies behind the cold front.
Context Anchor
Seen in aviation weather discussions, area forecasts, pilot weather briefings, and cold-weather flight planning.
Derivation
From the Greek arktikos, meaning 'near the Bear,' a reference to the Ursa Major and Ursa Minor constellations in the northern sky. The term came to describe the far north, and in meteorology it labels air masses that originate there.
Why Pilots Care
It can rapidly lower temperatures, increase the risk of icing, reduce aircraft performance, and require cold-weather starting and anti-icing procedures.
Grounding Statement
Picture air that has been sitting over the frozen Arctic for weeks, drained of moisture and chilled to extreme cold, then spilling south like cold water pouring out of a tilted bowl.
Intuition Check
Arctic air does not just mean any air that feels cold. It means an air mass that formed in, or came from, Arctic regions.
Example Sentence 1
The forecaster warned that a surge of Arctic air would push temperatures below freezing by morning, so the crew planned for cold-weather engine starts.
Example Sentence 2
With Arctic air in place the temperature dropped to minus fifteen, and we added extra time to the preflight to clear any frost from the wings.