A fresh low-pressure area is expected to develop over north Bay of Bengal and adjoining coastal Bangladesh and West Bengal around Monday. A preparatory cyclonic circulation will pop up over the region the previous day (Sunday). This became apparent after an existing low-pressure area over Odisha and adjoining plains of West Bengal weakened on Friday.
Shifting fortunes
The shifting fortunes of monsoon unfolded through Friday after the existing ‘low’ stalled earlier this (Friday) morning, with a trough from south-east Arabian Sea to Odisha across south Gujarat; northern parts of Madhya Maharashtra; Vidarbha; and Chhattisgarh merging with a larger trough east-west trough from south-west Rajasthan to Bangladesh across East Rajasthan; north Madhya Pradesh; north Jharkhand; and plains of West Bengal.
Monsoon trough prospects
The existing ‘low’ will now yield place to the emerging successor over north Bay of Bengal, effectively bending the eastern end of the east-west trough, in all likelihood proxy for the crucial monsoon trough, to dip into the Bay waters. This would accord likely lend better credibility, stability and sustenance for the trough, considered the backbone of the seasonal rainfall system.
The northern limit of the monsoon has stalled further over North India, and could likely get a move on once the monsoon trough forms, which would go on to ensure its arrival into Delhi around the normal time of June 30 and extend reach to entire country in next 2-3 days, India Meteorological Department (IMD) said.
Triggers heavy rain
Despite all its tantrums, the ‘low’ over Odisha and West Bengal brought extremely heavy rain over Assam and Meghalaya during the 24 hours ending on Friday morning. Heavy to very heavy rain lashed Odisha; Himachal Pradesh; East Rajasthan; West Madhya Pradesh; eastern Gujarat; Saurashtra and Kutch; Vidarbha; Tamil Nadu, Puducherry and Karaikal; South Interior Karnataka; and Kerala and Mahe.
Surpasses June estimates
Heavy rain lashed hills of West Bengal and Sikkim; Jharkhand; Uttarakhand; Haryana-Chandigarh-Delhi; Punjab; West Rajasthan; East Madhya Pradesh; Konkan and Goa; Madhya Maharashtra; Chhattisgarh and Coastal Karnataka. Overall rainfall for country as a whole remained at 9 per cent, surpassing IMD estimates for June, though masking major deficits across individual meteorological subdivisions. This explained why any monsoon need not ensure equitable distribution of rainfall across spatial and temporal scales.