The base observatory at Santacruz-Mumbai recorded 346.9mm of rainfall in June, against the normal figure of 493.1mm. The opening month of monsoon remained deficient by a huge 30% rainfall. Typical Mumbai rains with three-digit rainfall in 24 hours were missing. The highest 24-hour rainfall figures were 69mm and 66mm on 10th and 28th June respectively. The first three days of July gathered 61.7mm of rainfall and 52mm of these were recorded on 02nd July 2024.
The month of June has a shortfall of 146.2mm of rainfall. July is the rainiest month with an average rainfall of 840.7mm. Nearly 1000mm of rainfall is required in July to catch up with the deficiency. It is an uphill task and more so, when nothing big looks promising in the opening week of July 2024. Weather activity may pick up briefly during the next week.
The main triggers for monsoon rainfall along the Konkan Coast in general and Mumbai in particular are the off-shore trough along the Western Ghats and monsoon lows and depressions over the Bay of Bengal. Both these features have remained dormant for most of the time over the Indian seas, on either side of the coastline. Monsoon has been sailing, so far, under its own internal energy and dynamics and therefore remained on the life support systems for quite sometime in the month of June. Immediate recovery is unlikely and the lean phase will continue, to raise the rainfall deficit.
The distant sign of hope for revival, albeit marginal and brief, lies on a likely system over the northwest Bay of Bengal around the end of this week. This will not be a very strong system but still a broad cyclonic circulation may form over the Bay of Bengal, off the Odisha coast. This feature will quickly shift inland and move across Chhattisgarh and Madhya Pradesh. The presence of associated cyclonic circulation, while over West Madhya Pradesh, may trigger and intensify the westerly stream along the West Coast, between Coastal Karnataka, Goa and Konkan regions. Mumbai may get moderate to heavy rainy spells, short and sweet, between the 08th and 09th of July. It may not be adequate at all, to reduce the margin of shortfall, substantially. But, yes, it will break the jinx of thirsty conditions for the financial capital of India.