Question

Differenciate between retreating monsoon and south west monsoon?

Answer 1

When the retreating monsoon blows from the northeast across the Bay of Bengal, it picks up a significant amount of moisture, which is subsequently released after moving back onto the peninsula.That rainy extension of the generally dryretreating monsoon is called the northeast, or winter, monsoon.
The southwest monsoon - is generally expected to begin around the beginning of June and fade away by the end of September. The moisture-laden winds on reaching the southernmost point of the Indian Peninsula, due to its topography, become divided into two parts: the Arabian Sea Branch and the Bay of Bengal Branch.

Answer 2

Both refer the same. North east monsoon is also known as retreating monsoon. By end of september/early october wind reversal starts happening in north and central india.Mostly by end of october the winds change to easterlies in bay of bengal and arabian sea. During this time low pressure areas(LPA)/troughs form in bay of bengal and move towards TN/Sri Lanka coasts heralding the north east monsoon

Unlike south west monsoon, retreating monsoon does not have any semi permanent features and hence its very difficult to determine if it will be excess/normal/deficient in TN/south india.Usually before the start of north east monsoon/retreating monsoon depressions/cyclones form in bay of bengal in October. This in a way completes the wind reversal.

Retreating monsoon mainly gives rains to Tamil Nadu,Sri Lanka, Kerala and south coastal Andhra Pradesh. North coastal AP usually does not get much rain from retreating monsoon. Rest of south India including Karnataka does not receive heavy rains from this monsoon