The monsoon hit the Kerala coast two days behind schedule in 2021, but has already covered two-thirds of the country.
GS-I: Geography (Important Geophysical Phenomenon, Climatology)
Dimensions of the Article:
- How far has the monsoon progressed?
- Why is it early this year?
- Is this early onset of Monsoon unusual?
- Does early onset mean more rainfall overall?
How far has the monsoon progressed?
- 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 entire country except West Bengal and the Northeast, Jammu and Kashmir and Ladakh, Kerala, and Gujarat had received cumulative rainfall in excess (20%-59%) or large excess (60% or more) of normal.
Why is it early this year?
- 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.
- Despite a two-day delay from its normal onset over Kerala, the southwest monsoon made fast progress in subsequent days. This 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 early onset of Monsoon unusual?
- 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 all the other seven years, arrivals were delayed over major cities or regions. Cyclone Vayu in 2019 and Cyclone Mora in 2017 had delayed the monsoon progress by a few days.
- But overall, advancement during these seven years was as per normal dates and the monsoon covered the country around July 15 (the normal date, followed until 2019).
- 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.
Does early onset mean 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.
- For instance, the monsoon took 42 days in 2014 and 22 days in 2015 to cover the entire country. Even with such distinct ranges, India recorded deficient rainfall during both years.
- Ion 2021, the monsoon is most likely to cover the entire country by the end of this month. Although it is too early to predict the seasonal rainfall, it is possible that June rainfall could end in surplus over the normal of 170 mm.
How does early rainfall impact paddy sowing?
- Early rainfall will not directly impact paddy sowing, with seedlings still in the nursery stage in most paddy growing states.
- However, with not much rainfall recorded over Madhya Maharashtra (except Kolhapur, Satara & Sangli districts and the ghat areas) and Marathwada (except bordering districts with Vidarbha) farmers may undertake sowing once these sub-divisions get sufficient rainfall.
-Source: Indian Express