Bay of Bengal Low Pressure May Bring Telangana Rain; El Niño Keeps Deficit at 24%

A low-pressure area that has formed over the Bay of Bengal is expected to bring "good" rainfall to Telangana over the next three days, with the system likely to move towards Chhattisgarh and Gujarat. The spell offers some relief, but it does not change the larger picture: the State remains in the grip of a strong El Niño event, which meteorologists describe as one of the most intense in nearly three decades.

The Telangana Development Planning Society (TGDPS) says the prevailing weather pattern has contributed to a significant shortfall during the current southwest monsoon season. Telangana has received 48.8 cm of rainfall so far against a normal of 64 cm — a deficit of 24%. Of the State's 33 districts, 20 remain rainfall deficient.

El Niño refers to the warming of the central and eastern equatorial Pacific Ocean, a phenomenon that can weaken the Indian monsoon. Meteorologists classify conditions as strong when sea surface temperature anomalies in the equatorial Pacific exceed 1.5°C. The current event is around 1.8°C.

Senior weather consultant Y.V. Rama Rao said Telangana last experienced a comparably strong El Niño in 1997, when the monsoon deficit stood at 33%. Another poor monsoon year was 2014, when the overall deficit reached 29%, with monthly shortfalls of 58% in June, 36% in July, 14% in August and 16% in September.

"This year, rainfall was 12% below normal in June and 1% below normal in July. The deficit widened to 38% in August and has remained particularly severe in September — 79% so far — when rainfall has been almost absent in many parts of the State," Mr. Rama Rao said.

He noted that the impact on the rest of India was less severe in 1997 because of a positive Indian Ocean Dipole (IOD), a climatic phenomenon that can enhance rainfall over parts of the country and partially offset El Niño's influence. Its benefits, however, are not distributed evenly and may not significantly aid Telangana. Mr. Rama Rao added that since 2019, Telangana has generally recorded excess rainfall, particularly in August and September.

The dry spell has had another effect. Prolonged clear skies have pushed daytime temperatures 3°C to 4°C above normal, with maximum temperatures ranging between 35°C and 38°C. In Hyderabad, temperatures have generally stayed 2°C to 3°C above normal, at 33°C to 35°C. The city has recorded 37.4 cm of rainfall against a normal of 51.5 cm, a deficit of 27% till date.

There may be further relief towards the end of the month. According to Mr. Rama Rao, another low-pressure system is likely to develop over the Bay of Bengal after September 22, potentially bringing widespread rainfall to the State into the first week of October.

Monsoon performance is closely tracked in Telangana, where agriculture and water storage depend heavily on seasonal rainfall. The figures cited by the TGDPS are as recorded till the date of the assessment, and the outlook for the remaining days of September could still alter the final season tally.