Monsoon stalls over Maharashtra: IMD
With the southwest monsoon stalled over southern Maharashtra, India is facing a nationwide rainfall deficit of 41 pc between June 4 and June 18, according to the latest data from the India Meteorological Department (IMD). The country has received just 42.6 mm of rainfall, compared with the normal 72.2 mm, during the above-mentioned period.
IMD’s region-wise rainfall departure map shows that rainfall deficits in central India, east and northeast India, the southern peninsula, and northwest India stand at 67 pc, 42 pc, 22 pc, and 6 pc, respectively.
The weather department said on Thursday that “the absence of favourable large-scale meteorological conditions” was the key reason why the southwest monsoon has failed to advance further into the remaining parts of Maharashtra in the past few days. There are five main factors behind the slowdown in the monsoon’s northward progress.
First, the current monsoon flow lacks a strong surge from the Arabian Sea, according to the IMD.
“Such surges are generally responsible for enhanced moisture incursion and widespread rainfall leading to further monsoon advance,” said the weather department.
Second, low-level southwesterly winds associated with the monsoon circulation have weakened over the Arabian Sea. This has led to reduced moisture transport towards the Maharashtra coast and interior regions.
Third, the cross-equatorial flow over the western Indian Ocean and the Arabian Sea, which serves as a moisture source for the southwest monsoon, has weakened in recent years, resulting in reduced monsoon activity, according to the IMD.
Fourth, monsoon weather systems such as low-pressure areas or cyclonic circulations over the Arabian Sea and Bay of Bengal, or an offshore trough (a belt of low pressure extending over a large area) of sufficient intensity along the west coast to facilitate monsoon advancement, are currently absent.
The last factor is the weak phase of the Madden-Julian Oscillation (MJO), a moving system of winds, clouds, and pressure that brings rain as it circles the equator.
When it is in an active phase, it brings more clouds to southern India, which are then carried northwards by the monsoon winds, leading to enhanced rainfall.
“As a result, rainfall activity over most parts of Maharashtra is likely to remain isolated during the next 4-5 days,” said the IMD.
The southwest monsoon’s slow northward progress, coupled with the recent emergence of El Niño conditions over the tropical Pacific Ocean, which lead to reduced rainfall in India, can have significant consequences for kharif crops, which need timely rainfall to thrive.
On Tuesday, Union Agriculture Minister Shivraj Singh Chouhan directed that districts with a possibility of low or uneven rainfall be identified and that crop-wise contingency plans be prepared in coordination with state governments.
