PUNE: A major rainfall deficiency was observed in 2018 during August and September of the southwest monsoon. The forecasting of monsoon and other aspects were discussed by experts during a workshop on Thursday at the Indian Institute of Tropical Meteorology (IITM). The topic was ‘Role of weather and climate observations and forecasting on increasing agriculture productivity and risk management’.
During the workshop, AK Srivastava from the IMD, Pune, spoke on ‘An overview of SW Monsoon 2018’.
“It was seen that in the month of August and September, there were 16 subdivisions each, which had deficient rainfall. Also, in September, there were seven subdivisions, which had a large rainfall deficiency. The rainfall in August was 92 per cent of the Long Period Average (LPA) and for September, it was 76 per cent of the LPA,” said Srivastava.
He added that last year, El Nino was not fully developed.
“Along with El Nino, there were other factors, which may have played a vital role. In September, there was an absence of an atmospheric gradient, which may have been responsible for the poor rainfall activity,” said Srivastava.
He highlighted that the southwest monsoon last year witnessed less low-pressure events.
“There were formations of fewer low-intensity systems in the Indian oceans. Also, the movement of the low-intensity system on land was very fast, which caused less rainfall on land. There were also above normal cyclogenesis over the western Pacific oceans,” said Srivastava.
Along with this, he also highlighted that the season witnessed a lot of extremely heavy rainfall events.
“In June, Malvan in Konkan and Goa received 49 centimetres (cm) of rainfall on June 9, while Cherrapunji in Assam and Meghalaya received 38 cm of rainfall on June 24. Along with Kerala, many other places in the country reported high rainfall,” he said.
