We'd like to use analytics cookies to understand which symbols people look up, so we know what to research next. They are not used for advertising and we set none of them unless you say yes. What we store.
A tiny line drawing of how pressure has moved over three hours.
Also known as: Barometric tendency, Pressure trace
To the right of the station circle a small line drawing shows the shape of the last three hours of pressure change — rising, falling, rising then falling, steady. The shape matters as much as the amount: pressure falling and then steadying is a different forecast from pressure falling throughout.
Draws the shape of barometric change over the preceding three hours in one of a fixed set of small line forms.
Contexts: Navigation, Maps
Distinguishes patterns with the same net change, since falling-then-steady and steadily-falling imply different developments.
Contexts: Navigation, Maps
A short line bending once or twice, drawn beside a signed numeral at the right of the station circle.