An elongated area of low pressure on a weather map, associated with increased cloudiness, rain and unsettled conditions.
phenomenaWhat is Trough (Low Pressure)?
Troughs are extensions of low-pressure systems that appear as elongated dips in the isobars on weather maps. A monsoon trough is a semi-permanent trough that sits over mainland Southeast Asia during the wet season, enhancing convergence and rainfall. When the monsoon trough is active and well-defined, it produces the heaviest sustained rainfall of the monsoon season. Tropical cyclones can form within or near the monsoon trough.
Key points
- An elongated area of low pressure on a weather map, associated with increased cloudiness, rain and unsettled conditions.
- Category: phenomena
Related terms
See also: trough is connected to other weather concepts. Browse the full glossary for related definitions.