Monsoon prediction for 2021

Introduction

A good monsoon will aid agriculture, now one of the few bright spots in the economy

IMD predictions

If everything aligns, India could see a third consecutive year of surplus rainfall.
The IMD has said that monsoon rains will likely be 101% of the Long Period Average (LPA) of 88 cm.
In 2020, it was 109% of the LPA and in 2019, 110%.
While the forecast 101% LPA is short of the rainfall received in these years and still within the range of what the IMD considers ‘normal’ rainfall.
The current forecast is ‘above normal rainfall in the core agricultural zone.
- This zone includes States where agriculture is significantly rain-fed including Madhya Pradesh, Bihar, Odisha and West Bengal.
The IMD’s estimate of the distribution of this rainfall also suggests that except for the Northeast, where rainfall is expected to be ‘below normal, other regions are expected to get above normal rainfall.
- A general pattern of the monsoon is that weakened rains over Northeastern India — which has a higher base rainfall than other parts of India — translate into stronger rainfall in Central India.

Reason for above normal rainfall

No excess sea-surface temperatures at the Equatorial Pacific conditions.
There are also ‘negative’ IOD (Indian Ocean Dipole) conditions over the Indian Ocean during the monsoon season, meaning warmer water and greater precipitation in the eastern Indian Ocean.
Put together, they mean that these larger climate factors are, as of now, unlikely to have a significant influence over the prevailing monsoon.
A good monsoon could aid agriculture.
Boost in storage in the key reservoirs.
Forecast for a bounteous monsoon is the possibility of flash floods, landslides and disease outbreaks.
In the last year and before it, the IMD had not, in June, warned about the exceptionally high rains.
While three consecutive years of above-normal rain are exceedingly rare, the IMD itself assigns a 22% probability of it occurring, which is just below the 40% probability of ‘normal’ rainfall.

Way forward

India is now moving to a system where medium-range forecasts, or expected changes in monsoon or larger weather patterns over two weeks, are better captured by the monsoon models deployed.
These inputs must be used by the Government to better prepare infrastructure in the eventuality that excessive rains can wipe out the potential gains for agriculture.
It may also be worthwhile to encourage farmers to sow higher-value crops than only rice via the MSP route.
The favourable tidings should not be an excuse to abandon caution.