Monsoon depression
Topic: Climate of India and the Monsoon · NCERT: Beyond NCERT
Meaning
A monsoon depression is a low-pressure system that forms over the head (northern end) of the Bay of Bengal during the southwest monsoon. A low-pressure system is an area where air rises, which draws in moist winds and makes clouds and rain.
The depression moves west-northwest across central India along the monsoon trough, the long low-pressure belt over north India. As it moves, it brings heavy rain to the places on its path. A large share of the season's rain over central and north India comes from these depressions.
Example
In July or August, a depression forms over the northern Bay of Bengal near the Odisha-West Bengal coast. It moves inland over Odisha, Chhattisgarh and Madhya Pradesh, bringing heavy rain to each in turn.
Don't confuse with
- Tropical cyclone: this is a much stronger storm with very fast winds. In India cyclones strike mostly in the retreating monsoon season (October-November), especially the east coast deltas. A monsoon depression is weaker and is mainly a rain-maker.
Related concepts
- Southwest monsoon season
- Arabian Sea branch of the monsoon
- Rain shadow area
- Bay of Bengal branch of the monsoon
- Mawsynram
- Cherrapunji
- Dry Tamil Nadu coast in the southwest monsoon
- Break in the monsoon