Officially, monsoon withdraws from Bengal around October 10 after it arrives in early June. By Friday, Bengal had received 1,186.2mm rain against the normal count of 1,336.8mm, a deficit of 11%. The corresponding figures for Kolkata, too (1,086.7mm against 1,336.6mm), show a deficit of 19%.
The low-pressure formation, over northeast and adjoining east central Bay of Bengal, could bring at least moderate rainfall – of about 20mm a day – until Monday.
The Regional Meteorological Centre’s bulletin, released Friday, says the low pressure is “likely to become a well marked low pressure area and move northwestwards towards north Odisha and adjoining West Bengal coasts over the next 48 hours.” It ias likely to bring “enhanced rainfall activity… between September 29 to October 3,” the bulletin adds.
“We are likely to have moderate rainfall until at least Monday, possibly bringing 10mm to 20mm of rainfall to Kolkata a day,” said G K Das, director of RMC.
Lack of moisture led to dry spells
Despite a promising 40mm of rain on the first day of the season, monsoon arrived in Kolkata after a nine-day delay instead of the usual June 10. However, it soon ran out of steam, with June ending with a 38% rain deficit. This was further compounded by a 60% monthly deficit in July, which is usually the wettest month.
Lack of moisture entering the coastline from infrequent developments of relatively large systems like cyclonic circulations and low pressure areas in Bay of Bengal resulted in several consecutive days without showers in the first three monsoon months.
G K Das, the director of the Regional Meteorological Centre, said: “During a weak monsoon, there tends to be more localised rainfall. Then, the September surplus is carried over into the next month due to delayed monsoon withdrawal.”
