The monsoon did not make further progress towards North on Tuesday, apparently waiting for the Bay of Bengal to get active and push more rain into central and east India. Global models have been suggesting the formation of a low-pressure area off the Andhra Pradesh-Odisha coast this week to boost the monsoon in the region.
‘Low’ expected India Met Department has spotted an upper air cyclonic circulation over west-central Bay of Bengal off north Andhra Pradesh-south Odisha coasts. Its projections too favour the formation of a ‘low,’ which would cross coast and travel almost along a straight line across central India towards Mumbai-Gujarat.
This would likely bring another round of heavy to very heavy rainfall over central India and west India, covering Andhra Pradesh, Maharashtra, Gujarat, Madhya Pradesh, Chhattisgarh and Odisha.
The European Centre for Medium-Range Weather Forecasts and the US Climate Prediction Centre agree with this outlook.
The US Centre predicts that the rains will cover entire east India and northern parts of northwest India (Uttarakhand, Himachal Pradesh and Jammu and Kashmir) by June 28.
Dipole event The Application Laboratory (APL) of Jamstec, the Japanese national forecaster, persists with the outlook that the Indian Ocean would witness a ‘positive dipole phase’ soon.
It could start influencing the regional weather (which includes Indian monsoon) from August, the APL said in its latest update.
Indian Ocean Dipole mimics El Nino-La Nina in the equatorial Pacific; the positive phase is when the western part of the ocean warms up relative to the east, and vice versa.
The positive dipole phase has come to the rescue of the Indian monsoon in the past, notably in 1997, which was a strong El Nino year.
July trend It will be interesting to watch how this El Nino year plays out with a positive phase of the dipole being forecast.
The Japanese forecaster also said that India would likely witness a deficient monsoon in July.
August may turn predictably better with excess rain seen for central India and parts of adjoining north-west and east India. South India too may get good precipitation. But come September, the situation may reverse again with rain deficit forecast for most parts except in the east and north-east.
This goes to cast doubts on the strength or tenure of the positive dipole event.
Earlier on Tuesday, the Australian Met Bureau credited the good monsoon to unexpected support from the higher levels of the atmosphere in the form of a passing wave to the east.