The monsoon is expected to be normal in August and September, the India Meteorological Department said on Thursday in its forecast for the second half of the four-month rainfall season.
Quantitatively, the rainfall across the country as a whole during the two-month period is likely to be 100% of the Long Period Average (LPA) with a model error of plus or minus 8%, the IMD said.
The rainfall in August is likely to be 99% of the LPA with an error margin of plus or minus 9%, it said.
The LPA of the rainfall over the country as a whole for the second half of the monsoon season (August to September) based on the 1961-2010 period is 42.83 cm.
“The probabilistic forecast suggests that the rainfall across the country during the second half of the Southwest Monsoon season is most likely to be normal (94-106% of LPA) with a probability of 45%,” the IMD said.
In April, the IMD had made the forecast of a normal monsoon.
Mritunjay Mohapatra, Director General of IMD, said the next two weeks are expected to bring good rainfall due to formation of a low pressure area in the north Bay of Bengal.
The official rainfall season in India starts from June to September.
The overall rainfall deficiency in the country until July 31 was minus 9%. The deficiency on June 30 was 33%.
The coming two months are expected to be good as El Nino has entered a neutral phase and the Indian Ocean Dipole (IOD) is also positive.
“Currently, the sea surface temperatures (SSTs) as well as the atmospheric conditions over equatorial Pacific Ocean indicate El Nino Southern Oscillation (ENSO) neutral to borderline El Nino conditions,” according to the forecast.
“In addition to ENSO conditions over the Pacific Ocean, other factors such as the Indian Ocean SSTs (sea surface temperatures) have also some influence on Indian monsoon. Currently, positive Indian Ocean Dipole (IOD) conditions are prevailing over equatorial Indian Ocean,” it said.
El Nino is associated with heating of the Pacific waters while a positive IOD is linked to cooling of the Indian Ocean waters. Both are believed to impact the monsoon.
