Southwest monsoon stalls over Maharashtra
New Delhi, June 18: 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 India Meteorological Department (IMD) data.
The country has received just 42.6 mm of rainfall against the normal 72.2 mm during the above-mentioned period.
IMD’s region-wise departure rainfall 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 Arabian Sea, which acts as a moisture source for the southwest monsoon, has weakened during the recent period, resulting in a reduction in 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 to a large area) of sufficient intensity along the west coast that facilitates monsoon advancement, are absent as of now.
The last factor is the weak phase of the Madden-Julian Oscillation (MJO), which is a moving system of wind, cloud, and pressure that brings rain as it circles around the equator. (PTI)
