One Over the Bay Turned the Rain Tide for Telangana
“Cyclones,” he explained, “are entirely different, much stronger and bigger. While a cyclonic formation has a vertical height of around 15 to 18 kilometres from the surface, a deep depression is smaller with a height of around 5 km to maybe up to 8 km.”
Hyderabad: The rainfall deficit until 10 days ago in Telangana that was at a whopping 33 per cent, collapsed to a more healthy minus-5 per cent, that could be made up with few more good spells of rain as that experienced over the past few days.
So what changed? Did the ‘Super’ El Nino in the Central Pacific stop exerting its influence over India’s Southwest Monsoon season? Or did the Indian Ocean Dipole, the countervailing force that can help the monsoon overcome El Nino influence, decide to put in its appearance?
According to meteorologists, what appears to have ‘rescued’ the monsoon over Telangana, at least for now, was a depression. And a deep one at that, which formed over the Bay of Bengal, and moved inland slowly, churning the air, drawing moisture from the seas, and dumping it over Telangana, parts of Madhya Pradesh, Chhattisgarh, Maharashtra, and Karnataka.
Depressions and deep depressions are a normal weather phenomenon over the Bay of Bengal during the Southwest monsoon season. “The thing is these draw moisture not just from the Bay, but also from the Arabian Sea on the west. When there is a low pressure over the Bay, winds rush in over land, across the peninsula carrying with them moisture from the Arabian Sea adding to what the low pressure may be carrying from the Bay. There is convergence from all sides, but much of this is driven from the Arabian sea,” Dr G.N.R.S. Srinivas, senior meteorologist from the India Meteorological Department (IMD) said.
Typically, these weather phenomena, during the southwest monsoon season, begin forming because of the temperature difference between the landmass and the Bay of Bengal as the wind flows from the southwesterly direction, resulting in formation of either low pressure areas, or, if the conditions are conducive, depressions or deep depressions.
“Cyclones,” he explained, “are entirely different, much stronger and bigger. While a cyclonic formation has a vertical height of around 15 to 18 kilometres from the surface, a deep depression is smaller with a height of around 5 km to maybe up to 8 km.”
For Telangana, such depressions could be just the solution when the monsoon from the southwest takes a break, as has been the case this year for much of July. “For three weeks we had no rain, and suddenly in two to three days, here we are, at a minus-5 per cent deficit, which was exactly where the state was on July 31, 2025. Just 20 days ago, we were at minus-33 per cent,” he said.
Though similar low pressures or depressions also can form over the Arabian Sea during the monsoon season, they take their rain towards Gujarat, Northwest Maharashtra, with some spilling over northwest Telangana, Dr Srinivas said.
