Definition
An area of the atmosphere where the air pressure is greater than that of the surrounding air. In a high-pressure system (or 'high'), air descends from above and spreads outward near the surface. In the Northern Hemisphere, the Coriolis force deflects this outflowing air to the right, producing a clockwise circulation around the center of the high.
Plain English
A region where the air is heavier and pressing down harder than the air around it. The air sinks and flows outward, and because of the Earth's rotation, it spirals clockwise in the Northern Hemisphere.
Context Anchor
Seen on weather charts, forecasts, and discussions of large-scale wind flow, especially when studying how Earth’s rotation bends moving air.
Derivation
Pressure comes from a Latin word meaning “to press.” That helps here because atmospheric pressure is literally the weight of air pressing on the Earth’s surface. “High” means that pressing force is greater than in surrounding areas.
Why Pilots Care
High pressure systems shape wind direction and speed, influence weather stability, and guide route and altitude choices for smoother, safer flights.
Grounding Statement
Picture air slowly sinking over a wide area and then spreading out along the ground away from the center of that area.
Intuition Check
High pressure does not mean “strong wind” by itself. It means higher air pressure than nearby areas; the wind depends on how quickly pressure changes from one place to another.
Example Sentence 1
A high-pressure system was building over the region, so the pilot expected calm winds and clear skies for the morning departure.
Example Sentence 2
Pilots checked the high pressure area on the chart to anticipate clockwise wind flow around its center.