After the third lowest June rainfall in the recorded rain history of Kerala, July offers a sense of optimism and hope with the southwest monsoon, for the time in the current season, entering a vigorous mode. An offshore trough that now runs from the south Gujarat coast to the Kerala coast and the combined effect of a monsoon trough and cyclonic circulations over the Bay of Bengal have helped the monsoon revive after a month-long dry spell.
According to the statistics available with the India Meteorological Department (IMD), the lowest June rainfall deficit was recorded in 1976 with the opening month registering 196.8 mm of rainfall, followed by 244.93 mm in 1962, and 260.3 mm in 2023. As per the long-period average of Kerala, the State gets its highest share of rainfall in July (32.9% of the southwest monsoon rainfall’s seasonal total of 2018.7 mm), while June gets 32.6%, followed by August and September with 21% and 13%, respectively.
According to an IMD scientist, the current synoptic conditions are favourable for an active monsoon spell in July. However, the intensity of the current active spell may reduce by around July 7 and it will take at least one more week to get the monsoon to enter another vigorous mode over Kerala.
The current position of the offshore trough will slightly be changed in the coming days which may reduce the strength of the monsoon. However, it will be in its position soon. Though July offers some hope, the looming threat of El Niño is expected to have a direct bearing on the monsoon precipitation in August and September, he said.
Already, the central and eastern Pacific sea surface temperatures (SSTs) have exceeded the El Niño thresholds, and all international climate models suggest further warming of the central and eastern tropical Pacific Ocean. The only ray of hope is the development of a positive Indian Ocean Dipole (IOD) which is currently neutral in the week ending July 2, said the IMD sources.
The weekly SSTs for the period ending July 2 are above average across large areas of the central and western tropical Indian Ocean, and further warming of the Indian Ocean could reduce the ill effects of the El Niño, which typically brings dry weather to the Indian subcontinent, added the IMD sources.
