Now we know that the monsoon advance does not take on a day-by-day basis. It is a step-by-step process.

Ideally, starting from June 1, on an average, it takes nearly 45 days, i.e., by July 15, for the advance process to be completed.

The Arabian Sea branch of the SW Monsoon first hits the Western Ghats in Kerala, thus making this area the first state in India to receive rain from the SW Monsoon. This branch of the monsoon moves northwards along the Western Ghats – Coastal Karnataka, Konkan and Goa – with precipitation on coastal areas. Side by side, peninsular India and central India too are covered.

Meanwhile, the Bay of Bengal branch of the SW Monsoon that goes over the Bay of Bengal heads towards north-east India and Bengal. After the arrival at the Eastern Himalayas, the winds turn towards the west, travelling over the Indo-Gangetic Plains.

Then, bringing rains to Delhi-NCR region, Haryana, parts of Punjab and parts of north-west Madhya Pradesh, east Rajasthan, monsoon finally reaches the borders of West Rajasthan. The accompanying image is an old one but serves the purpose to explain the journey.

The two ends of our country – the Thar desert in the west and the Eastern Himalayas – offer contrasting picture when it comes to rains and yet, in some ways, have a similarity. While several places in Thar Desert are those that receive the least amounts of rains in India, in the Eastern Himalayas, Mawsynram situated on the southern slopes of the Khasi Hills in Meghalaya is one of the wettest places on Earth.

Tomorrow we see what the similarity is.


Image credit: By Saravask, based on work by Planemad and Nichalp.




---- to be continued