Early Progress of South West Monsson

Syllabus- General Studies 1 (Geography)

Aspects of the Physical Geography of India – Structure and Relief, Climate, Soils and

Vegetation, Geomorphic set up (Mountain Ranges and Rivers and other Water Bodies).

Context

The monsoon hit the Kerala coast two days behind schedule, but has already covered two-thirds of the country.

Fast Progression

• On June 15, the northern limit of the monsoon (NLM) continued to pass through Diu, Surat, Nandurbar, Bhopal, Nagaon, Hamirpur, Barabanki, Bareilly, Saharanpur, Ambala, and Amritsar, according to the India Meteorological Department’s daily weather report.
• Across some areas of south peninsular and central India, the monsoon has arrived 7 to 10 days ahead of its scheduled date. So far, the monsoon has missed Northwest India — Gujarat, Rajasthan, western Madhya Pradesh, Haryana, Punjab and Delhi.
• As of June 15, the entire country except West Bengal and the Northeast, Jammu and Kashmir and Ladakh, Kerala, and Gujarat had received cumulative rainfall (since the official beginning of the southwest monsoon season on June 1) in excess (20%-59%) or large excess (60% or more) of normal.

Reasons for fast paced spread

• Cyclone Yaas, formed in the Bay of Bengal during the third week of May, helped the monsoon make a timely arrival over the Andaman Sea on May 21.
• The fast progress was mainly due to strong westerly winds from the Arabian Sea, and also the formation of a low-pressure system over the North Bay of Bengal on June 11 that currently lies over eastern Uttar Pradesh and Bihar.
• The monsoon currents strengthened and it advanced into the Northeast, West Bengal, Odisha, Jharkhand, Bihar and parts of Chhattisgarh.
• An off-shore trough, prevailing for a week between Maharashtra and Kerala, has helped the monsoon arrive early over Karnataka, Goa, Andhra Pradesh, Telangana, Maharashtra and southern Gujarat.

Is this Normal?

• In the last one decade since 2011, the monsoon has covered the entire country in June itself on four occasions — 2020 ( June 1–26) , 2018 ( May 28–June 29), 2015 (June 5–26) and 2013 (June 1–16).
• In the years when the monsoon has arrived early, its progress has picked up towards the final phase; that is, the North and Northwest India regions have witnessed early arrival.

Will it continue this pace?

• Although the monsoon has made rapid progress along the regions on the west and east coasts, and East, Northeast and some Central India regions, further progress is likely to be slower. This is not expected until around June 25. An advance will take place when there is a fresh pulse to revive the monsoon currents.
• Also, a stream of mid-latitude westerly winds is approaching Northwest India, which will hinder the monsoon advancement in the immediate coming days.

Does early onset translates to more rainfall overall?

The time of monsoon onset over a region has no direct impact on the rainfall quantum received during the season, or in the monsoon’s progress.

Impact on Paddy sowing

Early rainfall will not directly impact paddy sowing, with seedlings still in the nursery stage in most paddy growing states like Maharashtra, Odisha and Bengal.

The early monsoon also means a shorter summer. Is this unusual?

• Although the IMD considers June 1 as the beginning of the monsoon season over India, the summer in Northwest India is not yet over. In West and Northwest India, day temperatures remain above 40°C. For example, Fatehgarh in eastern UP recorded 42.4°C on June 14.
• According to IMD Pune-Recently, Rajasthan and neighbouring areas of Northwest India reported heatwave-like conditions. Once the low-pressure system weakens in the next two to three days, the temperatures over North and Northwest India – where the monsoon is yet to reach – will increase.,

Can this occurrence be linked with Climate Change?

• After the monsoon onset over Kerala, its progress can either be rapid, consistent or slow, based on ocean-atmospheric conditions. The onset of the monsoon over various parts of the country each year can be ahead of time, in time or late.
• These variations are generally considered normal, given the complexity of the monsoon.

However, climate experts have linked extreme weather events like intense rainfall over a region within a short time span or prolonged dry spell during these four months as indications of climate change.

Question- Describe the reasons for fast spread of south west monsoon this year in India? Can it be linked to climate change?

Article- https://indianexpress.com/article/explained/southwest-monsoon-rainfall-season-kerala-coast-7360834/