Weather map symbols

Fronts

Symbols	Description
	A heat front is displayed by placing a number of red semi-circles on a line. This can be, for example, a long-lasting rain area, which in most cases leads to a cloud increase and simultaneously a slowly rising temperature.
	A cold front is represented by a line of blue triangles. Usually when there is a cold front, there is an unstable weather type where there is frequent thunderstorms and heavy showers. The air temperature goes down.
	An occlusion front is displayed by alternately placing purple triangles and semi-circles. An occlusion occurs when a rapidly moving cold front overtakes a slower heat front and merges with it. Because the heat and cold front at the core of the low-pressure area are closer together as a spiral, an occlusive front will manifest here first. Within an occlusion, the weather remains unstable with a lot of rain.
	Stationary fronts are represented by a line with alternating blue triangles and semi-circles on both sides of the line. A stationary front often lies between two pressure systems and therefore does not or hardly change position. The weather type is often characterized by thick layers of clouds, light or no precipitation at all, little or no wind and / or misty weather.
	Trough lines are drawn with a dashed line. A trough is an area with a relatively low air pressure connected to a low-pressure area where the isobars are most strongly curved, often behind a cold front. A trough is often characterized by showers.