Definition
An elongated area of relatively high atmospheric pressure extending outward from the center of a high-pressure system. On a surface weather map, a ridge appears as an outward bulge in the isobars, with the highest pressure running along its axis. Ridges are typically associated with descending air, light winds, fair weather, and few clouds.
Plain English
A long, narrow zone of higher pressure that sticks out from a high-pressure area. The weather along a ridge is usually calm and clear.
Context Anchor
Seen on surface weather maps when interpreting pressure patterns, wind flow, and likely weather changes along a route.
Derivation
From the everyday meaning of 'ridge' as a long raised strip — like the ridge of a roof or a mountain ridge. On a pressure map, the line of highest pressure forms a similar long, raised feature when you imagine the pressure field as terrain.
Why Pilots Care
Ridges usually bring stable air and lighter winds, helping pilots anticipate good VFR conditions and reduced turbulence.
Analogy
Think of a ridge on a weather map like a long raised area on a blanket. It is not one small peak; it stretches out in a line from a higher area.
Intuition Check
Do not read ridge as a mountain ridge here. In this weather-map context, it means a long area of higher air pressure.
Example Sentence 1
A ridge of high pressure was building over the region, so the pilot expected calm winds and clear skies for the cross-country flight.
Example Sentence 2
Crossing the ridge axis, the pressure gradient eased and our groundspeed increased with the lighter headwind.