Advancing Monsoon:

The advancing monsoon refers to the onset of the summer monsoon season in a particular region. This occurs when the southwest trade winds carry moisture-laden air from the Indian Ocean towards the landmass. It is a crucial weather phenomenon that brings much-needed rainfall to many parts of South Asia, including India, Nepal, Bangladesh, and Sri Lanka. Here are the key characteristics of the advancing monsoon:

1. Onset: The advancing monsoon begins with the arrival of the southwest trade winds over the Indian subcontinent. These winds start blowing from the Arabian Sea and Bay of Bengal, carrying moisture and causing a change in weather patterns.

2. Rainfall: The advancing monsoon is associated with heavy rainfall. As the warm and moist air reaches the landmass, it rises and cools, leading to the condensation of water vapor and the formation of clouds. The clouds then release precipitation in the form of rain, resulting in significant rainfall during this period.

3. Duration: The advancing monsoon typically lasts for several months, starting from around late May or early June and continuing until September. The duration may vary slightly depending on the specific region and its geographical features.

Retreating Monsoon:

The retreating monsoon, also known as the northeast monsoon, occurs when the southwest trade winds shift their direction and start blowing from the northeast. This phenomenon marks the end of the monsoon season in South Asia and affects mainly the southeastern coastal regions of India, such as Tamil Nadu, Andhra Pradesh, and parts of Sri Lanka. Here are the key characteristics of the retreating monsoon:

1. Onset: The retreating monsoon begins with a change in wind direction, as the southwest trade winds start shifting towards the northeast. This change is triggered by the movement of the sun towards the southern hemisphere, leading to a reversal in wind patterns.

2. Rainfall: The retreating monsoon is characterized by relatively lighter rainfall compared to the advancing monsoon. While the intensity of rainfall decreases during this period, some areas still experience intermittent showers and thunderstorms.

3. Duration: The retreating monsoon typically occurs between October and December. It is a transitional period between the summer monsoon and the winter season, as the weather gradually shifts from wet to dry conditions.

In conclusion, the advancing monsoon refers to the onset of the summer monsoon season with heavy rainfall, while the retreating monsoon marks the end of the monsoon season with lighter rainfall. Understanding these distinct phases of the monsoon is crucial for agricultural planning, water resource management, and overall climate analysis in South Asia.

*Arrival of monsoon is known as advancing of monsoon.
*Retrieval or ending of the monsoon season is known as retreating of monsoon. It is usually marked clear skies.