Definition
A large-scale weather system in which air circulates around a center of low atmospheric pressure. In the Northern Hemisphere the circulation is counterclockwise; in the Southern Hemisphere it is clockwise. Cyclones are typically associated with rising air, cloud formation, and unsettled weather.
Plain English
A weather system built around a low-pressure center, with air spiraling inward and upward. Lows on a weather chart are cyclones, and they generally bring clouds, wind, and precipitation.
Context Anchor
Seen in aviation weather reports, forecasts, weather briefings, and discussions of large-scale weather systems.
Derivation
From the Greek 'kyklon,' meaning 'moving in a circle' or 'whirling around.' That captures the essential idea: air rotating around a central point.
Why Pilots Care
Cyclones bring turbulence, icing, low ceilings, and strong winds that require route changes, altitude adjustments, or delays for safety.
Grounding Statement
Picture a broad weather system pulling air inward and making it turn as it moves toward the low-pressure center.
Intuition Check
A cyclone does not always mean a tornado or a hurricane. In aviation weather, it more generally means a rotating low-pressure system.
Example Sentence 1
The forecaster noted that a cyclone moving in from the west would bring lowering ceilings and rain along the planned route.
Example Sentence 2
We routed around the cyclone to avoid the associated widespread precipitation and turbulence.