Dryline
Also called dry line, dewpoint front, dryline symbol
Weather-map symbol. A chart convention, not a forecast icon.
Weather-map symbolsDryline meaning
A dryline is a dewpoint boundary drawn with scallops facing the moist air. The National Hurricane Center glossary describes it as a brown line. The scallops are the shape.
At a glance
- System
- Synoptic chart convention
- Used for
- A sharp dewpoint boundary
- Not the same as
- A cold front
Scallops facing the moist air. A moisture boundary, not a cold front.
The name. A dewpoint boundary. The National Hurricane Center glossary draws it with scallops toward the moist air.
Where it comes from
The NHC glossary calls a dryline a brown line with scallops facing the moist air. Brown is that glossary’s ink. A cold front’s triangles would say a different boundary. This drawing is a line of scallops in one gilt, facing one side, so the moist side is the side with the bumps. It does not encode a temperature change. Humidity is the field.
The line drawing is original to this cabinet. It is not an agency logo, a vendor icon, or the emoji for the same idea.
Weather
What it means
Moist air on the scalloped side, drier air on the other. Storms can fire on a dryline. The symbol does not mean they have. A trough can lie nearby and still be a pressure feature rather than a dewpoint front. Do not swap the scallops for triangles.
Questions
How is a dryline drawn?
The National Hurricane Center glossary describes a brown line with scallops facing the moist air. Brown is the ink. The scallops tell you which side is moist.
Is a dryline a cold front?
No. A cold front is a temperature boundary with triangles. A dryline is a moisture boundary. They can sit near each other on a plains map and still be two symbols.
Near this
- Cold frontA line with triangles in the direction of motion. Cold air is advancing. The color is a publisher’s aid.
- TroughElongated lower pressure and a wind shift. Not a front. The dash is a common habit, not a second alphabet.
- Squall lineA line of thunderstorms. The ticks on this drawing are a reading aid, not a required ornament.
- ThunderstormA forecast icon for thunder and lightning. Not a decorative bolt, and not ordinary rain.
Sources
Named when the entry depends on a text, a date, or a standard. Catalog numbers are not invented.
Your margin
Private. It stays in this browser and never joins the canon.
symbol.wiki, edited as Sigilla. Last reviewed 18 October 2026. A reading of public tradition, not a ruling.